Source string | Question string | Answer string | Question_type string | Referenced_file(s) string | chunk_text string | expert_annotation string | specific to paper string | Label int64 |
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IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | $$ \\frac { \\epsilon _ { x , I D s } } { \\epsilon _ { x } } = \\frac { 1 } { 1 + \\displaystyle \\frac { I _ { 2 , I D s } } { I _ { 2 , d i p . } } } $$ From Equation 1 we can also express the energy loss per turn as a function of $I _ { 2 , d i p }$ : $$ U _ { 0 } = P _ { 0 } / I \\approx \\frac { C _ { \\gamma } }... | augmentation | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | EXPERIMENTAL RESULTS The filter transmission functions, an example of which is presented on Fig. 4 left, are far from the desired $1 0 0 \\mathrm { n m }$ bandwidth ideals. This fact introduces an ambiguity in the transformation from the measured induced voltage to the beam distribution $U _ { i } \\to \\rho ( \\lambda... | augmentation | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | Patterned coatings had been developed elsewhere [5] to suppress eddy currents and, thereby, allow thinner coatings. Following this idea, we developed a patterned coating design with $2 { - } 3 \\Omega / \\mathrm { s q }$ and low field attenuation. The impedance and field attenuation were analyzed using CST Studio [6]. ... | augmentation | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | For a magnet with small gradient of its fringe field, the excitation efficiency drops down mostly due to vertical size increase of the $\\mathrm { H } ^ { 0 }$ beam at the interaction point (see Fig. 5) Beam size increases over the drift length $_ { \\mathrm { L } = 3 0 \\mathrm { c m } }$ due to initial angular spread... | augmentation | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | In this paper, we propose an improved lattice that takes chromatic effects into account and explore a method to compensate it. Simulations has been performed with the tracking program ASTRA [9] and the results demonstrate that a transverse emittance ratio of approximately 840 can be achieved by using the proposed metho... | augmentation | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | In this paper, we present the fully detailed design of XT72, along with the fabrication, RF tuning and high-power test results of the first XT72 structure. The results demonstrate its ability to operate at a gradient of ${ 8 0 } \\mathrm { M V / m }$ with a lower BDR. DESIGN We choose $2 \\pi / 3$ phase advance per cel... | augmentation | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | Table: Caption: Table 1: Lattice performance comparison between the standard lattice (STD) and the mini- $\\beta$ lattice (MB7). Tracking simulations are done with errors and corrections. The lifetime is calculated for $1 0 \\mathrm { p m }$ vertical emittance and $Z / n { = } 0 . 5 2 \\Omega$ . The brilliance is calcu... | augmentation | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | Figure 5 shows the resulting electric field profiles on the $z$ -axis along the first two cells at di!erent cell $\\# 0$ dimensions. Shorter gaps imply greater peaks of gradient, thus greater surface fields, although smaller than in regular cells where fields are more critical (Kilpatrick’s limit). It is also wor... | 1 | NO | 0 |
IPAC | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | Two optimization functions were defined. The first with an objective of minimization was the design’s volume $f _ { 1 } ( k )$ : $$ f _ { 1 } ( k ) = \\left[ k _ { 1 } ( 2 k _ { 2 } - 1 ) ( 2 k _ { 1 } + t ) + k _ { 1 } ^ { 2 } ( 2 k _ { 2 } + 2 ) + 4 8 k _ { 1 } \\right] 2 d k _ { 3 } , $$ where $t$ is the groov... | 1 | NO | 0 |
Expert | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | $$ { \\bf J } ( { \\bf r } , \\omega ) = \\frac { q } { 2 \\pi } { ( 2 \\pi \\sigma _ { x } ^ { 2 } ) } ^ { - 1 / 2 } \\mathrm { e } ^ { - x ^ { 2 } / 2 \\sigma _ { x } ^ { 2 } } \\mathrm { e } ^ { - i k _ { y } y } \\widehat { { \\bf y } } $$ with $k _ { y } = \\omega / \\nu$ . Using this expression, the electromagnet... | augmentation | NO | 0 |
Expert | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | 3D Simulations. 3D finite-element-method (FEM) frequency-domain simulations were performed in COMSOL to analyze effects originating from the finite height of the structure and beam. The structures were assumed to be $1 . 5 \\mu \\mathrm { m }$ high on a flat silicon substrate (Figure 1b). The spectral current density h... | augmentation | NO | 0 |
Expert | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | allows to design the spectrum $( \\omega )$ , spatial distribution $\\mathbf { \\Pi } ( \\mathbf { r } )$ , and polarization (e) of radiation by favoring one kind $| \\mathbf { e } { \\cdot } \\mathbf { E } ( \\mathbf { r } , \\omega ) |$ and penalizing others, $- | \\mathbf { e } ^ { \\prime } { \\boldsymbol { \\cdot ... | augmentation | NO | 0 |
Expert | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | A 200-period-long version of the inverse-designed structure was fabricated by electron beam lithography $\\bar { ( } 1 0 0 \\ \\mathrm { k V } )$ and cryogenic reactive-ion etching of $1 - 5 \\Omega \\cdot \\mathrm { c m }$ phosphorus-doped silicon to a depth of $1 . 3 \\big ( 1 \\big ) \\mathsf { \\bar { \\mu } m }$ .... | augmentation | NO | 0 |
Expert | Why does the inverse-designed grating exhibit higher efficiency than a conventional rectangular grating? | Because the photonic inverse design tailors the dielectric distribution to maximize directional emission and resonant coupling for the target wavelength. | Reasoning | haeusler-et-al-2022-boosting-the-efficiency-of-smith-purcell-radiators-using-nanophotonic-inverse-design.pdf | DISCUSSION Comparing the measured emission spectrum of the inverse design to its simulated profile shows that the observed emission was not as powerful and spectrally broader. We identify two causes: First, the electron beam current deteriorates as the beam diverges, where electrons hit the boundaries of the channel an... | augmentation | NO | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | Masks were made with hole diameters of 3mm and 5mm, to investigate decoherence caused by possible phase fluctuations across a given hole. Observations were made with integration times (frame times) of 1 ms and 3 ms, to investigate decoherence by phase variations in time. Thirty frames are taken, each separated by 1 sec... | 1 | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | D. 3ms vs 1ms coherences: 5 hole data We consider the affect of the integration time on coherence and closure phase on the 5-hole data (see Section VII for further analysis with other masks). Figure 22 shows the coherence at 3 ms vs 1 ms integrations. The 3 ms coherences are lower by about 2 - 10%. The rms of 3 ms cohe... | 4 | Yes | 1 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | We explore radii of 3, 5, 7, and 9 pixels, considering coherences and closure phases. Figure 19 shows the closure phases versus the u,v aperture radius. The closure phase values tend toward smaller values with increasing aperture size. The RMS scatter decreases substantially with aperture size until 7pix radius. Figure... | 4 | Yes | 1 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | Next we pad and center the data so that the centre of the Airy disk-like envelope of the fringes is in the centre of a larger two-dimensional array of size $2 0 4 8 \\times 2 0 4 8$ . To find the correct pixel to center to we first smooth the image with a wide (50 pixel) Gaussian kernel, then select the pixel with high... | 2 | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | Table I also lists the gains derived after image averaging, with and without Airy disk centering. In this case, the gains are essentially unchanged (within $1 \\%$ ), relative to the mean from the time series (row 1). This similarity for gain results from data that clearly involved decoherence of the visibilities thems... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | ‚Ä¢ The outlier dataset is the 5-hole 3ms data (yellow). This data set also has dropouts (see also Figure 23), but further, all of the points appear low, with a mean value substantially lower than all the other data sets, and with the largest rms scatter: $1 6 8 \\pm 1 1$ . Hence, comparing the 1ms data (5 and 3 holes)... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | I. INTRODUCTION We consider the measurement of the ALBA synchrotron electron beam size and shape using optical interferometry with aperture masks. Monitoring the emittance of the electron beam is important for optimal operation of the synchrotron light source, and potentially for future improved performance and real-ti... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | B. Processing Errors: Gaussian Random Approximation Beyond photon statistics, there are a number of processing steps that affect the resulting coherences, and hence the fit to the source size, including: uv-aperture size, bias subtraction, image centering, and others. In this section, we perform modeling of the uv-data... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | V. PROCESSING CHOICES The analysis presented herein is meant as supporting material for other papers that present the science results. Our main focus is to justify the choices made in this new type of analysis of laboratory optical interferometric data. A. Centering: phase slopes For reference, Figure 14 shows the cent... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | Figure 13 shows the closure phases for all ten triads in the uv-sampling, and the values are listed in Table III. All the closure phases are stable (RMS variations $\\leq 0 . 7 ^ { o }$ ), and all the values are close to zero, typically $\\leq 1 ^ { o }$ . The only triads with closure phases of about $2 ^ { o }$ involv... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | To check if some of the decoherence of 3 ms vs 1 ms data could be caused by changing gain solutions in the joint fitting process, in Figure 25 we show the illumination values for the 5-holes derived from 1 ms vs. 3 ms data from the source fitting procedure. The illumination is defined as $\\mathrm { G a i n ^ { 2 } }$ ... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | In radio interferometry, the voltages at each element are measured by phase coherent receivers and amplifiers, and visibilities are generated through subsequent cross correlation of these voltages using digital multipliers (Thomson, Moran, Swenson 2023; Taylor, Carilli, Perley 1999). In the case of optical aperture mas... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | IX. SUMMARY AND FUTURE DIRECTIONS A. Summary We have described processing and Fourier analysis of multi-hole interferometric imaging at optical wavelengths at the ALBA synchrotron light source to derive the size and shape of the electron beam using non-redundant masks of 2, 3, and 5 holes, plus a 6-hole mask with some ... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | We extract the correlated power on each of the baselines by calculating the complex sum of pixels within a circular aperture of 7 pixels, centered at the calculated position of the baseline. With the padding used here 1 mm on the mask corresponds to 2.54 pixels in the Fourier transformed interferogram. An illustration ... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | $$ where, $\\star$ denotes a complex conjugation. The process of calibration determines these complex voltage gain factors. In general, calibration of interferometers can be done with one or more bright sources (‚Äòcalibrators‚Äô), whose visibilities are accurately known (Thomson, Moran, Swenson 2023). Equation (2) is ... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | Figure 16 shows the center pixel locations derived using Airy disk centering for the 3-hole and 5-hole data. The X values are the same. But the Y values differ by 5 pixels. The largest departures from zero closure phase for the 5-hole data all involve baseline 0-2, which is the $1 6 \\mathrm { m m }$ vertical baseline ... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | A curious result from the source size analysis (Nikolic et al. 2024), was that the electron beam size derived with from the 5-hole mask with 3 ms averaging data resulted in a larger derived beam size than the 5-hole 1 ms data. We initially assumed this was due to temporal decoherence of the 3 ms data. However, the rota... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | III. EXPERIMENTAL SETUP The Xanadu optical bench setup at the ALBA synchrotron light source was the same as that used in Torino & Iriso (2016), including aperture mask location, reimaging optics to achieve far-field equivalence, narrow band filters centered at 538 nm with a bandwidth of 10 nm, and CCD camera imaging. T... | augmentation | Yes | 0 |
expert | Why is a non-redundant mask preferred in Carilli’s setup? | To ensure unique fringe spacings and avoid phase ambiguity from redundant baselines. | Reasoning | Carilli_2024.pdf | Note that the target source size is $\\leq 6 0 \\mu m$ , which at a distance of $\\mathrm { 1 5 . 0 5 m }$ implies an angular size of $\\leq 0 . 8 4 \\$ . For comparison, the angular interferometric fringe spacing of our longest baseline in the mask of $2 2 . 6 \\mathrm { m m }$ at $5 4 0 ~ \\mathrm { n m }$ wavelength... | augmentation | Yes | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | BEAM TEST The final beam experiment was carried out at BNL-ATFUED beamline. The 1.7MeV photoemission beam was injected to the FC lens. Three retractable Beam Profile Monitor (BPM) screens and associated cameras are the primary diagnostic tools. The upstream beam was focused using the RF photogun solenoid. Two upstream ... | augmentation | NO | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | Beam Position Monitors Figure 6 shows a typical example of the position measurement from a BPM against the set displacement. One BPM sits before the IP and another after; these plots are interpolations to the IP. Table 4 summarizes the agreement of the set and measured values for each scan taken. A slope of “1” cor... | augmentation | NO | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | File Name:BEAM-BASED_ALIGNMENT_OF_BEAM_POSITION_MONITORS.pdf BEAM-BASED ALIGNMENT OF BEAM POSITION MONITORS AT SLS 2.0 M. Böge→, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland Abstract Large initial beam position monitor (BPM) o!sets have to be reduced by one order of magnitude by means of beambased calibrat... | augmentation | NO | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | Table: Caption: Table 1: FCC-ee Mid Term Review (MTR) Parameters [2] Body: <html><body><table><tr><td>Running mode</td><td>Z</td><td>WW</td><td>ZH</td><td>tt</td></tr><tr><td>Beam energy [GeV]</td><td>45.6</td><td>80</td><td>120</td><td>182.5</td></tr><tr><td>Bunches /beam</td><td>11200</td><td>1780</td><td>440</td><t... | augmentation | NO | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | Over the past few years, we have focused on testing two beam size measurement setups, both based on x-ray diffraction optics. The first one is based on using Fresnel zone plates (FZP) and the second is based on diffraction using multiple crystals. FZPs allow imaging the beam in 2D, providing size and tilt information s... | augmentation | NO | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | Energy Calibration A principle task for the FCC-ee is ultra-precise measurement of electroweak $Z$ and $W$ ) observables, for which an accurately determined collision energy is key. This involves beam energy calibration every 10-15 minutes using noncolliding polarised pilot bunches (pilots), which circulate simultaneou... | augmentation | NO | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | A generator with the same properties used for the simulations was constructed, with the resulting beam propagated over $1 4 0 \\mathrm { m }$ . The measured transversal profiles are shown in Fig. 5. A clear resemblance to the simulation can be seen. The beam is optimized such that the central part of the pattern is vis... | augmentation | NO | 0 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | All the BPMs were calibrated at the start of the run with nominal intensity bunches, by looking at the reconstruction of the beam position while the beam orbit was fixed and the jaws were moved together in ten steps of $2 0 0 \\mu \\mathrm { m }$ . The calibration showed an excellent slope of $1 . 0 0 3 \\pm 0 . 0 4 3$... | augmentation | NO | 0 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | D. Coupling dependence of the measured beam profiles The coupling dependences were measured by changing the currents of the skew-quadrupole coils wound on two kinds of sextupole magnets. Figure 20 shows the typical beam profiles when a skew correction was carefully carried out [Fig. 20(a)] and all of the skew-quadrupol... | 5 | NO | 1 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | The Q-scan curve obtained for the y-direction is shown in Fig. 3. Where $\\sqrt { | K | }$ is a value proportional to the focusing force of the quadrupole magnet. Fitting using Eq. (3) results in an emittance $8 \\%$ lower than the simulation input. This is because the beam in the y-direction is shaved o! about $1 \\%$... | 4 | NO | 1 |
IPAC | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | ALIGNMENT TOLERANCES & BBA Two optics were developed, named the Global Hybrid Correction (GHC) and Local Chromatic Correction (LCC) optics, respectively. Table 2 presents the rms misalignments of arc quadrupoles and sextupoles leading to $1 \\%$ rms beta beating or $1 \\mathrm { m m }$ rms spurious vertical dispersion,... | 4 | NO | 1 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | This paper is organized as follows. In the next section, we briefly present the principle of the FZP monitor. In Sec. III, we show the experimental setup of the FZP monitor, especially the improvements. Some measurement results by using the improved FZP monitor are shown in Sec. IV. The last section is devoted to concl... | 2 | NO | 0 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | As the shutter opening time becomes shortened, the background component becomes larger than the peak signal of the obtained beam image. In order to measure the beam profiles precisely and analyze them in detail, we carefully subtracted this background component from the data of $\\mathbf { X }$ -ray CCD, as follows. Th... | 4 | NO | 1 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | E. X-ray pinhole mask The background on the CCD image mainly consists of the readout noise of the $\\mathbf { X }$ -ray CCD circuit and the $\\mathbf { \\boldsymbol { x } }$ -ray beam transmitted through the FZPs, which is not focused at all. The transmitted x rays through the MZP appear on the x-ray CCD as a square of... | 4 | NO | 1 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | DOI: 10.1103/PhysRevSTAB.10.042801 PACS numbers: 07.85.Qe, 07.85.Tt, 41.75.Ht, 41.85.Ew I. INTRODUCTION A. Introduction to the FZP monitor The production of low-emittance beams is one of the key techniques for electron accelerators and synchrotron light sources. For example, a third-generation synchrotron light source ... | augmentation | NO | 0 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | We briefly summarize the history of measurements of emittance in the ATF damping ring. First, the horizontal emittance was successfully measured by the tungsten and/ or carbon wire scanner set on the extraction line [3], and was also measured by a double-slit SR interferometer. However, the vertical emittance was not c... | augmentation | NO | 0 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | Beam emittance in the ATF damping ring is dominated by the intrabeam scattering effect [2]. In a high current of the single-bunch mode, the emittance increases as the beam current become high, and the coupling ratio decreases. In order to estimate the coupling ratio of the ATF damping ring and validate these measured b... | augmentation | NO | 0 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | $$ where the $\\lambda$ is the wavelength of a photon and $f$ is the focal length for the wavelength. The spatial resolution $\\delta$ which is the transverse size of a point-source image for the 1st-order diffraction on the focal plane, is determined by $$ \\delta = 1 . 2 2 \\Delta r _ { N } , $$ where $\\Delta r _ { ... | augmentation | NO | 0 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | The diffraction limit is determined by the wavelength of x-ray SR $\\lambda = 0 . 3 8 3 ~ \\mathrm { { n m } }$ , which corresponds to $3 . 2 4 \\mathrm { k e V } \\mathrm { x } .$ - ray energy, and the divergence angle $\\sigma _ { { \\mathrm { S R } } }$ of $1 2 6 \\ \\mu \\mathrm { r a d }$ , which is obtained from... | augmentation | NO | 0 |
Expert | Why is beam-based alignment critical for the FZP monitor? | It prevents optical aberrations that distort beam profile measurements. | Reasoning | Sakai_2007.pdf | The beam-profile monitor with x-ray imaging optics will allow precise and direct beam imaging in a nondestructive manner because the effect of the diffraction limit can be neglected by using x-ray SR. Some beam-profile monitors based on the x-ray imaging optics were performed by using FZP and a refractive $\\mathbf { \... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | associated with varying delays in the digitization paths for different groups of channels. INTRODUCTION Ionization Profile Monitors (IPMs) have been developed at Brookhaven National Laboratory (BNL) to measure transverse beam profiles in RHIC [1–3]. When the beam passes through the beamline, it ionizes the background... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | The dependence of the axially symmetrical beam density on the radius is measured by averaging one arch of beam imaged discussed above. The centre of the distribution is reconstructed from the shape of the arch. An example of the beam arch picture at $1 4 0 0 { \\mathrm { ~ e V } }$ is presented on Fig. 5 (left). The sc... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | INTRODUCTION With the increasing demand for hadron beam therapy, there is a parallel rise in the demand for online, non-invasive beam diagnostics. However, most of the commercially available diagnostics are either fully invasive to the beam or if less invasive, can still effect the properties during the measurements. T... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | A laserwire diagnostic is under development for installation on the Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) [5]. FETS consists of 5 sections; an ion source, a low energy beam transport (LEBT), a radiofrequency quadrupole (RFQ), a medium beam energy transport (MEBT), and a laserwire diagn... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | At the entrance of the beam delivery pipe, a motorized platform is present, which hosts the beam entrance diagnostics. These include a Faraday Collector to measure beam intensity and an optical system to display the beam spot on a fluorescent ceramic. In order to reduce the scattering of the beam, the propagation in th... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | Beam Position Monitors Figure 6 shows a typical example of the position measurement from a BPM against the set displacement. One BPM sits before the IP and another after; these plots are interpolations to the IP. Table 4 summarizes the agreement of the set and measured values for each scan taken. A slope of “1” cor... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | Table: Caption: Table 1: Transport Matrix Elements Body: <html><body><table><tr><td colspan="4">SlitstoFODOStart</td></tr><tr><td></td><td>Sim.</td><td>Meas.</td><td>|△|</td></tr><tr><td>M11</td><td>-0.359</td><td>-0.388 ± 0.000</td><td>0.03</td></tr><tr><td>M12</td><td>0.161</td><td>-0.262 ±0.002</td><td>0.42</td... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | $$ \\mathcal { T } _ { j } = \\frac { \\mathrm { v } } { c S } j + \\mathcal { T } _ { 0 } $$ $$ I _ { j } = C _ { t o t } \\frac { \\sum _ { i } \\mathcal { P } _ { i j } } { \\sum _ { i j } \\mathcal { P } _ { i j } } \\frac { c S } { \\mathrm { ~ v ~ } } $$ The pair $\\{ \\mathcal { T } _ { j } , I _ { j } \\}$ repr... | augmentation | NO | 0 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | The measurement was performed by focusing the beam on the first FC using the Tandem injector ion optics [4]. Then measuring the profiles in the plane of the first FC and in the plane of the second FC in steps of $1 \\mathrm { m m }$ in $y$ direction. Obtained beam profiles as a function of Faraday cup position $y _ { F... | 4 | NO | 1 |
IPAC | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | This also leads to having unusable data points when individual pre-amplifiers for a channel fail giving disconnected data points within a profile. During data analysis, the channels that were marked to be inoperative were set to the average value of the overall IPM data set to eliminate the poor MCP issue. Out of all 6... | 2 | NO | 0 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | V. CONCLUSION In this paper, we have presented an improvement of the FZP monitor and measurement results of the ultralow emittance beam in the ATF damping ring under various conditions. First, by thermally disconnecting the Si crystal from the stepping motor, the position drift of the obtained image was drastically red... | 5 | NO | 1 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | From these measurements, we conclude that the beamsize enhancement, especially vertically, is caused by the $1 0 0 ~ \\mathrm { H z }$ oscillation; the FZP monitor, itself, is working well, and electron beam might be oscillated with $1 0 0 ~ \\mathrm { H z }$ frequency. 3. Data analysis and results For data analysis, f... | 5 | NO | 1 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | B. Si monochromator The Si crystal monochromator can be rotated horizontally by using a goniometer and vertically by using a stepping motor, which is attached to the support of a Si crystal in a vacuum. With the old monochromator, the vertical position of the beam image on the CCD camera had largely drifted because the... | 4 | NO | 1 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | FIG. 10. (Color) Typical beam image obtained by the FZP monitor after the background was subtracted. Beam current was a $4 . 4 \\mathrm { \\ m A }$ in a single-bunch mode. The shutter opening time was fixed to $1 \\ \\mathrm { m s }$ . The horizontal and vertical bars of $5 0 ~ \\mu \\mathrm { m }$ show the scales at t... | augmentation | NO | 0 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | Beam emittance in the ATF damping ring is dominated by the intrabeam scattering effect [2]. In a high current of the single-bunch mode, the emittance increases as the beam current become high, and the coupling ratio decreases. In order to estimate the coupling ratio of the ATF damping ring and validate these measured b... | augmentation | NO | 0 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | IV. MEASUREMENT OF THE ULTRALOW EMITTANCE BEAM IN THE ATF DAMPING RING A. Beam tuning and condition We obtained a data set of the beam profile mainly for three days with various damping-ring conditions after improving the FZP monitor. In all cases the ATF ring was operated at $1 . 2 8 \\mathrm { G e V }$ in single-bunc... | augmentation | NO | 0 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | Table: Caption: TABLE I. Expected spatial resolution of each parameter and the total expected spatial resolution. Body: <html><body><table><tr><td>Parameters</td><td>Definition</td><td>Resolution (1σ)[μm]</td></tr><tr><td>Diffraction limit (λ= 0.383 nm)</td><td>λ/4TTOSR</td><td>0.24</td></tr><tr><td>Airy pattern o... | augmentation | NO | 0 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | D. Fast mechanical shutter 1. Layout The time resolution of this monitor is determined by the minimum shutter opening time of the mechanical shutter. We newly install a fast mechanical shutter in the $\\mathbf { X }$ -ray beam line in order to improve the time resolution to less than $2 0 ~ \\mathrm { { m s } }$ . Figu... | augmentation | NO | 0 |
Expert | Why is it important to measure the tilt of the beam profile in the FZP monitor? | Because x–y coupling can distort the vertical size measurement if beam tilt isn’t accounted for. | Reasoning | Sakai_2007.pdf | $$ where the $\\lambda$ is the wavelength of a photon and $f$ is the focal length for the wavelength. The spatial resolution $\\delta$ which is the transverse size of a point-source image for the 1st-order diffraction on the focal plane, is determined by $$ \\delta = 1 . 2 2 \\Delta r _ { N } , $$ where $\\Delta r _ { ... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | INTRODUCTION Particle accelerators are among the grandest machines of the twentieth century because of their contributions to medicine, materials development, renewable energy, and the many fields of high-energy physics and life sciences, with roughly a third of all Nobel Prizes in physics being related to the use or a... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | INTRODUCTION In recent years charged particle acceleration using solidstate nanostructured plasmas has attracted attention as a novel method of achieving ultra-high acceleration gradients, beam manipulation and gamma- or $\\mathrm { \\Delta X }$ -ray generation $[ 1 -$ 10]. In this context, PIC simulations have shown t... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | Starting from the idea proposed by Tajima and Dawson [1], who first suggested accelerating electrons produced by the interaction of a laser with a plasma, there have been many advances in laser wakefield acceleration (LWFA) over the years. These advances are largely due to significant progress in laser technology, whic... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | INTRODUCTION To perform physics precision studies or discover physics beyond the Standard Model, high-energy colliders such as the existing Large Hadron Collider (LHC), the past Large Electron-Positron (LEP) or the Future Circular Collider (FCC) [1, 2] are desireable. However, limitations such as speed or radio-frequen... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | File Name:ION-ION_COLLISIONS_IN_PLASMA_WAKEFIELD_ACCELERATORS.pdf ION-ION COLLISIONS IN PLASMA WAKEFIELD ACCELERATORS M.Yadav‚àó, K. Letko, J.B. Rosenzweig University of California, Los Angeles, California, USA Abstract The plasma wakefield accelerator, with acceleration gradients ranging from $\\mathrm { G e V / m }$ ... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | File Name:DESIGN_AND_MODELING_OF_DIELECTRIC_A_WAKEFIELD.pdf DESIGN AND MODELING OF DIELECTRIC A WAKEFIELD ACCELERATOR WITH PLASMA IONIZED WITNESS BUNCH N.M. Cook,‚àó RadiaSoft LLC, Boulder, CO, USA G. Andonian, K. Kaneta, A. Pronikov, RadiaBeam Technologies, Santa Monica CA, USA Abstract A planned experiment at the Arg... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | File Name:SiPM_INTEGRATION_TESTING_FOR_FACET-II_PAIR_SPECTROMETER.pdf SiPM INTEGRATION TESTING FOR FACET-II PAIR SPECTROMETER J. Phillips‚àó, B. Naranjo, M. Yadav, J. B. Rosenzweig University of California, Los Angeles, CA, USA Abstract A pair spectrometer, designed to capture single-shot gamma spectra over a range ext... | augmentation | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | File Name:CHARACTERIZATION_OF_METER-SCALE_BESSEL_BEAMS_FOR.pdf CHARACTERIZATION OF METER-SCALE BESSEL BEAMS FOR PLASMA FORMATION IN A PLASMA WAKEFIELD ACCELERATOR T. Nichols ‚àó, R. Holtzapple, California Polytechnic State University, San Luis Obispo, CA, USA R. Ariniello, S. Gessner, SLAC National Accelerator Laborato... | 2 | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | The Livingston plot, shown in Figure 1, illustrates how the progress in achieving the energy frontier has been enabled by the history of invention in accelerator science and technology. One can clearly see that over several decades, there has been an exponential growth in the maximum attained energy. But the exponentia... | 2 | NO | 0 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | THE AWAKE EXPERIMENT AWAKE is an R&D experiment at CERN with the aim to develop proton-driven based plasma wakefield acceleration. The wakefields are driven by highly-relativistic ${ \\mathrm { 4 0 0 G e V } }$ , relativistic factor $\\gamma _ { p + } \\sim 4 2 7 )$ and energetic $( > 1 9 \\mathrm { k J } )$ proton bun... | 1 | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | The beam has geometric transverse emittances of $\\varepsilon _ { x } = 9 . 5 \\times 1 0 ^ { - 1 0 } \\mathrm { m }$ and $\\varepsilon _ { y } = 1 . 2 \\times 1 0 ^ { - 1 0 } \\mathrm { m }$ . It is focused with a quadrupole doublet to a spot with $1 0 \\mu \\mathrm { m }$ radius at the entrance of the plasma. With th... | 5 | NO | 1 |
IPAC | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | Plasma wakefield accelerators must be able to replicate the performance of large particle accelerators to be viable for applications in colliders and light sources. Both applications require high-quality electron beams with low emittance. The incoming electron beam possesses a divergence in the transverse direction inv... | 4 | NO | 1 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | At each of the two planes, the particle distribution is measured by imaging Cherenkov radiation emitted as the electrons pass through a $1 5 \\mathrm { - m m }$ -wide air gap established by two silicon wafers (not shown in Fig. 1), positioned at an angle of $4 5 ^ { \\circ }$ to the beam. The second wafer acts as a mir... | augmentation | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | File Name:Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf Energy doubling of 42 GeV electrons in a metre-scale plasma wakefield accelerator Ian Blumenfeld1, Christopher E. Clayton2, Franz-Josef Decker1, Mark J. Hogan1, Chengkun Huang2, Rasmus Ischebeck1, ... | augmentation | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | Thus, the full ionization extends over a radius of more than $1 0 0 \\mu \\mathrm { m }$ and ionization begins far earlier than the peak of the bunch current. Because the ionization region extends over a radius larger than the plasma collisionless skin depth $c / \\omega _ { \\mathrm { p } } ,$ where $\\omega _ { \\mat... | augmentation | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | In a plasma wakefield accelerator large-amplitude electric fields result from space-charge waves excited by the passage of an ultrarelativistic electron beam through a plasma12. A fully ionized plasma can be formed in a neutral vapour when the radial electric field of the electron beam exceeds the field ionization thre... | augmentation | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | We used simulations to explain the maximum electron energy observed in the experiment. Figure 2b shows a comparison of the measured energy spectrum with one derived from simulations. The electron current distribution is extracted from the energy spectrum of the beam measured upstream of the plasma by comparing it to a ... | augmentation | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | Recent plasma wakefield accelerator experiments have shown high-gradient acceleration of electrons using a 10-cm-long plasma11. To obtain energy gains of interest to high-energy physics, these high gradients must be extended over metre-scale plasmas. Such an extension transitions the plasma wakefield accelerator from a... | augmentation | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | Images of the dispersed electrons are recorded along with the relevant beam parameters on a shot-to-shot basis. The energy gain achieved for each shot is determined as described in the Methods section. Figure 2 shows one example of the electron energy distribution between 35 and $1 0 0 \\mathrm { G e V }$ after travers... | augmentation | NO | 0 |
expert | Why is lithium used in plasma wakefield accelerators | Because of its low ionization potential | Fact | Blumenfeld_et_al._-_2007_-_Energy_doubling_of_42_GeV_electrons_in_a_metre-scale_plasma_wakefield_accelerator.pdf | When the length of the lithium vapour column was extended from $8 5 \\mathrm { c m }$ to $1 1 3 \\mathrm { c m }$ , the maximum energy in an event with a similar incoming current profile was measured to be $7 1 \\pm 1 1 \\mathrm { G e V }$ . Less than $3 \\%$ of a sample of 800 consecutive events showed an energy gain ... | augmentation | NO | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | Finally, particular attention has to be paid to the shape of the distributions in Fig. 9(b). They are not Gaussian. For such a high fluxes, this cannot depend on the detector resolution, at least for the CpFM 2 channel which has the better efficiency. This can be demonstrated deriving the CpFM 2 resolution for an incid... | 1 | Yes | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | beam profile monitors) Cherenkov detectors In-vacuum detectors High-energy particle accelerators A B S T R A C T The UA9 Experiment at CERN-SPS investigates channeling processes in bent silicon crystals with the aim to manipulate hadron beams. Monitoring and characterization of channeled beams in the high energy accele... | 1 | Yes | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | 5.2.1. Channeled beam profile In the channeling plateau, the linear scan shown in Fig. 8(b) basically corresponds to integrate the channeled beam profile in the horizontal plane. Therefore it can be fitted with an error function: $$ e r f ( x ) = A \\cdot { \\frac { 1 } { \\sigma { \\sqrt { 2 \\pi } } } } \\int _ { 0 }... | 2 | Yes | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | File Name:CpFM_paper.pdf Commissioning and operation of the Cherenkov detector for proton Flux Measurement of the UA9 experiment F.M. Addesa a,‚àó, D. Breton d, L. Burmistrov d, G. Cavoto a,b, V. Chaumat d, S. Dubos d, L. Esposito c, F. Galluccio e, M. Garattini c,g, F. Iacoangeli a, J. Maalmi d, D. Mirarchi c, S. Mont... | augmentation | Yes | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | 1. Introduction The primary goal of the UA9 experiment [1] is to demonstrate the feasibility of a crystal-based halo collimation as a promising and better alternative to the standard multi-stage collimation system for high-energy hadron machines. The main installation of the experiment is located in the Long Straight S... | augmentation | Yes | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | 3.2. PMT gain optimization While choosing the PMT gain for both proton and ion runs, the maximum expected flux has to be considered together with the photoelectron yield per charge and the WaveCatcher dynamic range. To determine the optimal gain is noticed that the saturation of the ADC occurs at $2 . 5 \\mathrm { V }$... | augmentation | Yes | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | Using the value above and the value of the $\\sigma$ of the channeled beam obtained by the fit shown in Fig. 8(b), it is also possible to extrapolate the angular spread of the particles exiting the crystal. It can be derived subtracting the equivalent kick for $x _ { C p F M } = { \\bf c } \\pm \\sigma$ from $\\theta _... | augmentation | Yes | 0 |
expert | Why the CpFM features to identical fused silica bars? | One bar is devoted to the direct beam flux measurement , the other one to the background characterisation. | Fact | CpFM_paper.pdf | In Fig. 7 the angular scan of the UA9 crystal-1 during a proton run is shown. It is displayed both by the BLMs and the CpFM (CpFM position is such that both the bars intercept the whole channeled beam when the crystal is in the optimal channeling position). The first and the last angular regions (angle $< - 2 7 0 0$ μ... | augmentation | Yes | 0 |
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