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618d66f6-a8b9-4610-80a2-11f6b4317262 | 24Online optimization at SXFEL
Validity test in the control room
Improving FEL lasing intensity
Testing various optimization algorithms
Challenges for online tuning and control
Lasing output often decays with time
Periodic jitters is hard to eliminate
H
V11 pm ~ 6 am
Subway Line 2
1.3 km
Maglev train line
0.3 k... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD2_talk.pdf | 23 |
1a792711-a234-4cf0-8d0e-cccd46ac9d2d | 25Conclusion
ML approaches have been widely investigated in operation of XFELs/accelerators,
automatic control and online optimization
Thank you for your attention!
zhuzihan@sinap.ac.cnRemaining challenges
Fill in the gap between simulation and measurement
More physics-informed, sample-efficient, general ML method... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD2_talk.pdf | 24 |
e7d73c2a-dd9e-4dd1-b254-5201578da4a3 | Efficient tuning of particle accelerator
emittance via Bayesian algorithm execution
and virtual objectives
Ryan Roussel*, Sara Miskovich, Willie Neiswanger, Auralee Edelen, Dylan Kennedy
Daniel Ratner
rroussel@slac.stanford.edu | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 0 |
437e5674-21d3-4331-ba5f-c81ae5210b2a | 2Outline
•Motivation
•Emittance optimization and multi -point measurements
•Methods
•Standard Bayesian optimization approach
•Information based Bayesian optimization using virtual objectives
-Bayesian Algorithm Execution (BAX)
•Results
•Online optimization of emittance at LCLS | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 1 |
383ad98f-2829-4357-b4b8-64c183f1fbb4 | 𝜎𝑥2=1+𝑑𝑙𝑘2𝝈𝟏𝟏+21+𝑑𝑙𝑘𝝈𝟏𝟐+𝑑2𝝈𝟐𝟐
𝜀=𝜎11𝜎22−𝜎122
3Online Emittance Optimization in Accelerators
Quadrupole scan emittance measurement:
•Minimizing transverse beam
emittance is critical to the
performance of accelerators, including
light sources and colliders
•Hand tuning accelerator parameters to
m... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 2 |
0f12345f-039b-450a-bfe8-6be3ba79bd3c | 𝜎𝑥2=1+𝑑𝑙𝑘2𝝈𝟏𝟏+21+𝑑𝑙𝑘𝝈𝟏𝟐+𝑑2𝝈𝟐𝟐
𝜀=𝜎11𝜎22−𝜎122
4Online Emittance Optimization in Accelerators
Quadrupole scan emittance measurement:
Replace with autonomous optimizer:
~10-30 measurements
One emittance measurement
(1-3 mins) | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 3 |
e35ee2ff-9751-42e8-875b-e972f3ebb551 | 5Bayesian Optimization (BO)
Create a computational
model of the systemPick the point that
maximizes valueDetermine the value of
potential future
measurements
Why?
-Surrogate model assisted optimization performs better than
conventional optimization algorithms –especially for global optimization
-Bayesian surrogate... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 4 |
e53b03b4-a9a8-47ec-b1ab-a1e2a5f647ec | 6Bayesian Optimization of Emittance in Accelerators
~10-30 measurements
One emittance measurement
(1-3 mins)
Emittance measurement
Note: vertical axis
normalized by
minimum ground
truth emittanceAcquisition function LCLS injector simulation Surrogate model (Gaussian process) | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 5 |
22cbaf80-9a51-451e-b440-7b92d7fa45b1 | 7Challenges Facing Emittance Optimization
~10-30 measurements
One emittance measurement
(1-3 mins)
Tuning param
(e.g.solenoid)
Measurement parameter
(e.g.matching quadrupole)Emittance
measurement
Beam size measurement
𝜀1 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 6 |
25409492-1118-44db-974f-ceea7940963d | 8Challenges Facing Emittance Optimization
~10-30 measurements
One emittance measurement
(1-3 mins)
Tuning param
(e.g.solenoid)
Measurement parameter
(e.g.matching quadrupole)Emittance
measurement
Beam size measurement
𝜀1𝜀2 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 7 |
4151cea8-6253-4e57-959f-80b505d8ec43 | 9Challenges Facing Emittance Optimization
~10-30 measurements
One emittance measurement
(1-3 mins)
Tuning param
(e.g.solenoid)
Measurement parameter
(e.g.matching quadrupole)Emittance
measurement
Beam size measurement
𝜀1𝜀2
𝜀3 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 8 |
3bf06b2a-64f7-439f-b49b-a081a4458f83 | 10Challenges Facing Emittance Optimization
~10-30 measurements
One emittance measurement
(1-3 mins)
Tuning param
(e.g.solenoid)
Measurement parameter
(e.g.matching quadrupole)Emittance
measurement
Beam size measurement
𝜀1𝜀2
𝜀3𝜀4 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 9 |
54f775b5-a650-4479-9711-e2ff9b22aa55 | 11Challenges Facing Emittance Optimization
~10-30 measurements
One emittance measurement
(1-3 mins)
Tuning param
(e.g.solenoid)
Measurement parameter
(e.g.matching quadrupole)Emittance
measurement
Beam size measurement
𝜀1𝜀2
𝜀3𝜀4𝜀5 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 10 |
c639d4c5-b29f-400e-8ce1-1273f2b2da16 | 12Challenges Facing Emittance Optimization
~10-30 measurements
One emittance measurement
(1-3 mins)
Tuning param
(e.g.solenoid)
Measurement parameter
(e.g.matching quadrupole)Emittance
measurement
Beam size measurement
𝜀1𝜀2
𝜀3𝜀4𝜀5Issues w/ multi -point measurements:
•Sample inefficient
•Information inefficient
•... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 11 |
7b01c3cd-f3d7-4748-a51d-1304a3e6f2c0 | 13An Alternative Approach
~10-30 measurements
One emittance measurement
(1-3 mins)
Tuning param
(e.g.solenoid)
Measurement parameter
(e.g.matching quadrupole)Emittance
measurement
Beam size measurement
Instead:
•Build a surrogate model from
beam size measurements
(much easier to measure)
•Predict emittance from vir... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 12 |
87dc0323-9fd8-492a-bc5d-a82aebed5872 | 14Bayesian Algorithm Execution (BAX)
Our goal:
Determine the ideal tuning
configuration 𝒙∗which
minimizes emittance
Beam size model
Predict beam emittance as a
function of tuning config.
(with uncertainty)
Predict optimal tuning config.
(with uncertainty)
Miskovich, et. al., arXiv:2209.04587 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 13 |
7b37812f-4953-43cf-b0d4-afe8b6b14785 | 15Bayesian Algorithm Execution (BAX)
Our goal:
Determine the ideal tuning
configuration 𝒙∗which
minimizes emittance
Beam size model
The BAX algorithm chooses beam
size measurements that reduce
uncertainty in 𝒙∗→without
measuring emittance directlyPredict beam emittance as a
function of tuning config.
(with unce... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 14 |
4c339d16-2666-4652-84c5-9656439f21a3 | 16LCLS Simulated Demonstration
Note: vertical axis
normalized by
minimum ground
truth emittance•In simulation BAX significantly reduces
(20x) the number of beam size
measurements needed to find optimal
tuning configuration
•Compare beam size model predictions
with experimental measurements to
gauge convergence ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 15 |
06cfe28c-71de-4e81-ab75-f9dab7bf848e | 17LCLS Experimental Demonstration
Miskovich, et. al., arXiv:2209.04587
10 random initial beam size
measurements~ 2 minutes runtime
(model convergence)== a few quad scans | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 16 |
50cbbf94-8cb6-4aa0-b185-2f3a3786c6c8 | 18Future Work
•Embedding physics -informed structure into the
GP model
•Incorporate measurement constraints
•Integration into the open -source framework for
advanced optimization, Xopt (poster THPL164)
(https://christophermayes.github.io/Xopt/ )
Enforce known
quadratic dependence
from first -order beam
optics
Bad... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 17 |
70e632b2-131a-457b-9f46-1d2944cf455f | 19Conclusion
•Bayesian Algorithm Execution (BAX) significantly (~20x) reduces the time
needed to optimize multi -point measurements like beam emittance using
virtual objectives
•Data driven algorithms can be used in a variety of contexts in order to
speed up optimization of multi -point experimental measurements. | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 18 |
3d358711-1e94-4f72-86ee-f2d744c35364 | 20Questions? | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 19 |
47fa1601-eaa4-41f0-8e4a-febfe6a48a46 | 21Our Approach: Bayesian Algorithm Execution (BAX)
Bayesian
optimization
cycle:
BAX optimization cycle:Real →virtual
measurementEmittance measurement
Beam size measurement | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 20 |
4ab75c68-7bdd-48de-b7d9-c6aa778e7ff2 | 22BAX: Virtual Emittance Measurements
Virtual emittance measurement:
•Draw samples from the beam
size model
•Fit 2ndorder polynomial for each
sample at each tuning parameter
•Calculate emittance from each
sample
•Aggregate emittance data into a
predictive distribution | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 21 |
999a8b95-116f-4610-bd36-6b51fc6f35d9 | 23BAX: Predicting Ideal Tuning Parameters
Determine the ideal tuning
parameter 𝒙𝒕∗that minimizes
emittance:
•For each sample of the emittance
function find the tuning parameter
𝑥𝑡∗that corresponds to the
minimum emittance
•Calculate the distribution 𝑝(𝑥𝑡∗)𝑝(𝑥𝑡∗) | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 22 |
41f4f3d8-b157-4b34-8542-6de18a32b7b3 | 24BAX: Information Gain
Additional observations {𝑥,𝑦}result in
information gain (IG) about the ideal tuning
parameter 𝑥𝑡∗
𝑝(𝑥𝑡∗)with new data
set𝐷∪𝑥,𝑦
(low uncertainty)Information
gain
𝑝(𝑥𝑡∗)
𝑝(𝑥𝑡∗)with original
data set 𝐷
(high uncertainty) | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 23 |
cf373458-4ef1-4117-823b-e5fbe11fbc4a | 25BAX: Expected Information Gain Acquisition Function
Uncertainty of 𝑥𝑡∗reduced
(information gained)𝐸𝐼𝐺𝑥=𝔼𝑝𝑦𝑥,𝐷[𝐼𝐺(𝑥,𝑦)]Pick observation points 𝑥that are likely to increase the
information gain the most:
Expected information gain
Samples drawn from
beam size modelInformation gain | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOD - MC06.1 - Beam Instrumentation, Controls, Feedback & Operational Aspects (Contributed)\MOOD3_talk.pdf | 24 |
bee4dec8-b134-49e7-9668-d1684d853f67 | X-BAND ACTIVITIES AT INFN-LNF
F. Cardelli∗, D. Alesini, F. Anelli, M. Bellaveglia, S. Bini, B. Buonomo, S. Cantarella,
G. Catuscelli, M. Ceccarelli, R. Ceccarelli, A. Cecchinelli, P. Chimenti, M. Cianfrini,
R. Clementi, C. Di Giulio, E. Di Pasquale, G. Di Raddo, R. Di Raddo, A. Falone,
L. Faillace, G. Franzini, A. Gall... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 0 |
20bae5ee-35cf-4838-ae10-5af63b3d54ef | thelastyearsinordertoprovethereliabilityandfunctionality
oftheX-bandtechnologyatveryhighpeakpower. Themain
stepofthisactivityhasbeentheimplementationofaX-band
teststationTEX,basedonanRFpowersourcecapableto
deliver50MWRFpulsesthatareusedforacceleratingstruc-
turesandRFcomponentsconditioningandtesting. Thistest
facilityh... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 0 |
cdacd67c-9f2f-4ed2-80ab-0891f8bcba13 | Frascati national laboratories of the INFN, on the X-band
radio-frequency technology. This technology has proven to
increasetheperformanceoflinearacceleratorsintermsof
maximum accelerating gradient (> 100 MV/m) and com-
pactness. For this reason it was chosen as the basic tech-
nology for the realization of the Linac b... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 0 |
be35d6db-6219-4814-8dc6-90bc3dee287d | Figure1reportsasketchoftheRFLinac. Toincreasethe
FELperformancesafutureupgradeof theinjectorwithan
high repetition rate C-band (5.712 GHz) Gun working at
400 Hz is being studied [3]. The booster RF module con-
sistsina25MWklystronbasedpowersourcefeedingtwo
acceleratingstructuresinparallelbymeansofaBOCtype
∗fabio.cardel... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 0 |
10ce3279-0793-4b83-ac39-4b2b62345615 | InthispaperwereportthestatusandfutureworkoftheTEX
facility, and the progress on the design and testing of the
different RF components that realize the X-band module of
the Linac, with particular attention to the pulse compressor
and the X-band accelerating section prototypes.
Figure 1: View of the EuPRAXIA@SPARC_LAB Li... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 0 |
d95e32f3-4ad2-4346-b561-b0642fb7e958 | powerisdividedwitha3dBhybridandsenttotwotravelling
waveX-bandacceleratingstructuresterminatedonspiralRF
loads. The RF signals (forward and reflected) are measured
via directional couplers, positioned after the klystron and at
the input and output of the sections. In Fig. 2 we report the
sketchedlayoutofthesingleRFmodul... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 0 |
dc524035-c938-44f7-a62b-99d233f18a96 | the ongoing R&D and testing activity related to the main
components of the RF module.
Figure 2: a) Sketch of the RF module. b) Details of the
distribution line to the RF structures.
POWER SOURCES AND TEX FACILITY
ForthechoiceofthefinalX-bandsourcetwomainsources
are currently under study. The first is based on klystron
... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 1 |
23064bf7-668e-4be1-99c7-56075335cd34 | allowtohalvethenumberofsourcesgoingtofeed4struc-
turespersource,butdoublingthepeakworkingpowerfor
the pulse compressor and all RF components of the mod-
ule. BoththetwosolutionswillbetestedatLNFandtheir
performance and reliability compared. Currently a power
sourcebasedonCPIVKX8311klystronisinoperationin
our test facil... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 1 |
331e91d0-70c1-44cd-87b7-354bde50fbff | the all waveguide distribution terminated on two titanium
spiral loads, realized withadditivemanufacturing, was com-
pleted in February 2023. In Fig. 3 is possible to see the
loadsconditioninghistory,wherethetrendoftheloadsin-
putpower(blue),theklystronforwardpower(yellow)and
the RF pulse length (red) are reported. Dur... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 1 |
c2859c37-9d5c-4702-8a97-986cef23f6ca | system. The TEX operation has been interrupted at the end
of February by construction work inside the building that
houses the facility. In April 2023 an accelerating section
of the T24 CLIC type [7], on loan from CERN, has been
installed inside thebunker as preparation of thenextexper-
imentalrun. Thistestwillbeuseful... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 1 |
64c03be6-12b2-47a0-9a85-9535e971d652 | BOC PULSE COMPRESSOR AND RF
COMPONENTS
For the energy upgrade of the current RF source of the
TEX facility, a BOC type pulse compressor will be installed
alongtheline. ThisX-bandBOCisbeingpurchasedfrom
thePSI.Atthesametime,forthefuture25MWstation,that
willbeinstalledatTEX,anotherpulsecompressorisneeded.
Therefore, we a... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 2 |
c5b4ad54-6454-4316-888a-2652b406b43d | ofthegaskettosealthecavitywiththewaveguidethatsur-
roundsit. InTable1arereportedthemaindesignparameters
oftheBOC.Thechoiceoftheresonantazimuthalmodeand
thereforethequalityfactor 𝑄0andthecouplingcoefficient 𝛽
were guided by the optimization performed during the elec-
tromagneticdesignoftheEuPRAXIAacceleratingstructure... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 2 |
f00d44fd-8e9a-4e23-9300-3ea02fbc59a0 | have beencarried outin parallel. In Fig. 5are reportedthe
snapshotofthemagnitudeoftheelectricfieldobtainedfromtheEM simulationand thepreliminarymechanicallayout
of the BOC components. The mechanical design still needs
tobefinalizedinordertorealizeaprototypebytheendof
this year. Many of the other X-band components that ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 2 |
94f5c6d2-473e-4a99-9916-0fd0440f1603 | unit in circular waveguide we based our design on the so
called"wraparound"modeconverter[11]. Aprototypeof
mode converter with circular waveguide pumping unit is in
construction and will be soon available for testing. Another
component that we are realizing is a modified version of the
Titanium spiral loads made by add... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 2 |
4809661a-8e4c-452f-a1f8-76fcfc1b4e6c | is being manufactured.
Figure 6: Entire view and section of the modified Spiral
Load for machining and brazing.
X-BAND ACCELERATING STRUCTURE
The EuPRAXIA@SPARC_LAB X-band accelerating
structureiscurrentlyinaprototypingphase. Theelectromag-
netic design of the structure has been completed, it aimed
to minimize the modi... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 2 |
80d252e3-c909-4b0c-93a2-ac3ce7081a1a | Hzand400Hz. Fourcoolingchannelsareintegratedintothe
cell,runninglongitudinallyalongthestructure,withinlets
and outlets on the couplers. By means of this analysis it has
been verified that the cooling system is able to compensate
the increase of temperature and the consequent detuning of
thecavitiesduringtheoperationfor... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 3 |
9c85ee3a-8035-48b3-8cb5-71a8032835f1 | somereiterationswiththemechanicaldesignandsubsequent
modification,haveledtothefinalmechanicaldesign. The
prototypingactivityinvolvesfourmainsteps. Thefirstisthe
onejustdescribed,concerningthecreationofsmallsamples
of cells to optimize the brazing process and complete the
mechanical project. This activity has been also ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 3 |
8ba72727-d009-4bec-94fe-e68568cd9e12 | tain the alignment of the structure during the assembly of
the cells and during the brazing phase, each cell is fixed
to the next by means of screws. The cells are assembled
together before brazing on an ultra-precise graphite support,
inserting the brazing alloy and fixing each cell to the next
by means of three screw... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 3 |
c26e3225-553d-45af-b6a5-1a3a7d41c967 | TEXfacility. Currentlythecellsofthisstructurearebeing
machinedand then willbe brazedin our laboratory. TheRF
powertestisexpectedlaterthisyear. Finally,afull-scaleRF
prototype will be built to be tested at TEX and conditioned
at full power.
CONCLUSION
In the framework of the EuPRAXIA@SPARC_LAB
project, which involves th... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 3 |
5b8659f7-9b29-4b2b-9204-88e7277e7eef | Average Acc. Gradient MV/m 60
Structure per module 2
Average Iris radius mm 3.5
Tapering Angle degree 0.04 0
N. of cells 112
Shunt impedance 𝑀Ω/𝑚93-107 100
Effective Shunt impedance 𝑀Ω/𝑚350 347
Average input power MW 51
Average dissipated power kW 1
𝑃𝑜𝑢𝑡/𝑃𝑖𝑛 % 25
Peak mod. Poynting Vec. 𝑊/𝜇𝑚23.6 4.3
Peak ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 3 |
dd40134d-980c-4f56-9e97-9d24518f87da | REFERENCES
[1]M. Ferrario et al.,"EuPRAXIA@SPARC_LAB Design study
towards a compact FEL facility at LNF" , Nuclear Instruments
and Methods in Physics Research Section A: Accelerators,
Spectrometers,DetectorsandAssociatedEquipment,vol.909,
pp. 134-138, Jan. 2018.
doi:10.48550/arXiv.1801.08717
[2]D. Alesini et al.,"EuPRA... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 4 |
1989dd3e-caa3-4cd0-827e-ba504a58c827 | Bangkok, Thailand, Jun. 2022, pp. 1148-1151.
doi:10.18429/JACoW-IPAC2022-TUPOPT061
[6]S.Pioli,F.Cardelli, P.Ciuffetti,C.DiGiulio,R.Gargana,and
D.Moriggi,“ControlandFunctionalSafetySystemsDesign
forReal-TimeConditioningofRFStructuresatTEX”,in Proc.
IPAC’22, Bangkok, Thailand, Jun. 2022, pp. 751-753.
doi:10.18429/JACoW-I... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 4 |
d52bdad3-8cc2-4ae1-a370-bf5d883ae68b | doi:10.18429/JACoW-IPAC2022-MOPOMS019
[10]N.Catalan-Lasheras et al.,“HighPowerConditioningofX-
BandRFComponents”,in Proc. IPAC’18 ,Vancouver,Canada,
Apr.-May 2018, pp. 2545–2548.
doi:10.18429/JACoW-IPAC2018-WEPMF074
[11]S. Tantawi et al.,"Evaluation of the TE(12) mode in circular
waveguide for low loss, high power RF t... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1.pdf | 4 |
346b7a93-aa02-43a9-8556-028b899fb120 | X-band activities at INFN- LNF
Fabio Cardelli
On behalf of the EuPRAXIA and the TEX technical team
National Institute of Nuclear Physics, INFN -LNF, Frascati, Italy14th International Particle Accelerator Conference -IPAC23
May 7 - 12, 2023 Venice, Italy | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 0 |
d1bde76b-b12a-4bbb-9208-c45a52196e2f | Outline
1.EuPRAXIA@SPARC_LAB project and linac
2.X-band RFmodule layout
3.TEX facility
•Conditioning ofwaveguide and loads
•Current layout
4.RFpower source
5.X-band RFcomponents
•Machined spiral load and mode converter
•Brazing free BOC pulse compressor
6.X-band accelerating structure
•Electromagnetic and mechanical de... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 1 |
3768fdf8-f7fe-4c81-a686-64110e971656 | EuPRAXIA @SPARC_LAB project
»The project EuPRAXIA@SPARC_LAB aims at constructing a FEL radiation source
(λFEL=3 nm) based on RF linear accelerator combined with a plasma module [1,2]
»We are currently in a preparatory phase of the TDR for this machine
»The project is one of the pillar of the European Project EUPRAXIA ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 2 |
a80d2cda-b4b9-46a8-8cc9-3747b3aa4bde | S-band structure and 3x2mTWS-band structures
»X-band (11.994 GHz) booster composed by16x
TW, 0.9maccelerating structures with anominal
gradient of60MV/mNormal conducting RF linac
S-band power
stationsX-band power
stations
Magnetic
chicanePlasma
acceleration
module
[1] Ferrario et al., NIM A 909, (2018) pp.134- 138... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 2 |
33165caa-acef-4155-b76e-852ab960d42b | X-band RF Module Layout
BOC pulse compressor
(PSI design or INFN brazing free)
Hybrid
(CERN design)
Pumping units
(CERN design)
NEXTORR Pumps
(SAES)X band structures
(INFN design)
DC
(CERN design)Power Source: Solid State
Pulsed Modulator + KlystronMode converter
(INFN -SLAC design)
Spiral RF LOADS
(CERN Design)
ci... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 3 |
8881134d-7bd8-4945-b5bb-2c49417b80d3 | TEX Facility
»The TEst -stand forX-band (TEX) isconceived forR&D and test onhigh
gradient X-band accelerating structures, RFcomponents, LLRF systems,
Beam Diagnostics, Vacuum system and Control System
»Ithasbeen co-funded byLazio region intheframework oftheLATINO
project (Laboratory inAdvanced Technologies forINnOvatio... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 4 |
03e3c6d1-ce8e-4958-8de5-b1dbe9ef355b | RF output amplitude
stability< 0.09 %
RF output phase
stability20.9 fs»The civil engineering works inthebuilding has
been concluded inAugust 2021
»The installation and commissioning ofthe
Modulator and klystron hasbeen completed in
February 2022 [3].Atthe same time LLRF
system [4],EPICS control system have been
commiss... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 4 |
d1a21a4b-6a06-4400-8600-b3e6c463f5e9 | Solid State Modulator
Scandinova k400Klystron CPI
VKX8311AX-band RF Power Source
Currently wehave a test stand based on CPI VKX8311A Klystron
Two other klystrons will be tested at TEX:
A.CANON E37119
»Low modulator peak power requirement
»Very high repetition rate (Interesting for a future upgrade of the
machine)
»... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 5 |
2f59f576-f420-4758-ba65-e102fa9c5a64 | RF pulse length μs 1,5
Repetition Rate Hz 400 100 100
Gain dB 47 50 47
Efficiency % 40 55 40
Status :
•Test station based ontheVKX8311 Aklystron already commissioned
and inoperation atTEX facility
•CANON E37119 klystron with modulator isinprocurement phase
(expected delivery 01/2024)
•CPI VKX8311 HE isinprocurement pha... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 5 |
7cc184ba-8f88-44c1-badb-c4757d6002c7 | Conditioning of waveguides and Spiral Loads
»Aconditioning run ofthe waveguide distribution line terminated ontwo 3D
printed Titanium Spiral Load hasbeen completed inFebruary 2023
»Afinal forward klystron peak power of42MW with 250 nspulse length at50Hz
has been reached in3weeks .The test has been interrupted toperform... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 6 |
02ce7ad1-e96b-4c68-84cb-5a7b4db3e3e9 | Current TEX layout
»In April 2023 we installed, inside the bunker, a CERN accelerating section of the T24 CLIC type. The complete setup is being implemented in
these weeks
»This test will be preparatory to the conditioning of the first EuPRAXIA accelerating structure prototype , which will take place by September
202... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 7 |
fdb19a25-397a-4b6c-8487-637ad319a9ef | X-band RF components
»Many ofthe X-band components needed forthe EuPRAXIA module are
based onCERN design and have been manufactured, purchased and
installed inthe TEX layout :directional couplers, pumping units, splitter,
loads [6]
»AnX-band BOC hasbeen ordered toPSI
»Atthesame time, wearedeveloping other components :
... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 8 |
342b9898-8cbe-4cda-a7dd-c336e83bf879 | •EMand mechanical design: done
•Manufacturing byacompany :ongoing
[6] N. Catalan- Lasheras , et al., 9th Int. Particle Accelerator Conf. (IPAC18), Vancouver, BC, Canada, May 2018, paper WEPMF074.
[7] S. Tantawi, et all. (2000). Reviews of Modern Physics –doi: 10.1103/PhysRevSTAB.3.082001 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 8 |
f07be9c0-9c04-4369-a07b-e227590676ef | Brazing free BOC pulse compressor
»We are developing a new design
for X -band BOC that implements
the INFN -LNF brazing -free
technology
»The brazing free or “clamping”
technology is based on the use
of special RF/vacuum gaskets
[8,9]
»The choice of the mode to
increase the Q0keeping the size
of the BOC reasona... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 9 |
bf88309c-f394-4ef1-8135-1b6e61356ca9 | X-band Accelerating structures design
PARAMETERValue
Quasi -
Constant
GradientConstant
Impedance
Frequency [GHz] 11.9942
Average acc. gradient [MV/m] 60
Structures per module 2
Iris radius a [mm] 3.85 -3.15 3.5
Tapering angle [ deg] 0.04 0
Struct. length Lsact. Length [m] 0.94
No. of cells 112
Shunt impedance R [MΩ/m]... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 10 |
976f4722-aa67-4da0-97a4-cd7bb2afacf3 | average irisradius design towork with anaverage acceleration gradient of60
MV/m .The single cell and RFstructure optimization has been completed
developing asemi -analytical code toconsider also the power gain from the BOC
pulse compressor [10]:done
»Thermo -mechanical simulations todemonstrate the correct sizing ofthe... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 10 |
239391d0-05c4-4280-ac45-11c38ed4fc09 | Structure Prototyping Activity
Four main steps ofprototyping :
• Pre-prototypes on3-cells and simplified couplers to
test and optimize the brazing procedure, cells
assembly, alignment etc:done
• Full scale mechanical prototype :0.9mprototype
totest the overall brazing process ofthe full
structure and thecell-to-cell al... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 11 |
277f0fdd-1a2c-4461-b056-b65b5c53963a | Full- Scale Mechanical Prototype Brazing
•Vacuum test OK (except one coupler for a
miss -positioning of the brazing alloy)
•Straightness ±15 µm obtained after brazing
(±30 µm required by BD)Results on the brazed structure
Next steps
•CI 15 cells RF prototype expected by July 2023
•Final full- scale structure expected... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 12 |
d8c30245-41d6-473f-b8af-c4f9ab8f3df0 | Conclusions and Acknowledgements
Aknowledgements :
INFN -LNF: D. Alesini, S. Bini, B. Buonomo , S. Cantarella , R. Clementi, A. Gallo, C. Di Giulio, E. Di Pasquale, G. Di
Raddo , A. Liedl, V. Lollo , L. Piersanti, S. Pioli, R. Ricci on behalf of the TEX and EuPRAXIA technical team, INFN -LNF
Accelerator Division and ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 13 |
eb0f20d8-521a-4852-8f45-04b5b1d1b88d | willbetested inthenext months
»Anew X-band RFsource based onthe25MW, 400Hz E37119 klystron willbecommissioned atTEX
starting from February 2024
»Ahigh efficiency klystron version ofthe 50MW VKX8311 Adeveloped byCPI/CERN should be
available from beginning 2025
»Many X-band RFcomponents ofthe EuPRAXIA RFmodule have been ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG1_talk.pdf | 13 |
8a4b9670-bf21-4318-a782-539f950975c7 | CHARACTERISATION OF MICROBUNCHING INSTABILITY AT THE
FERMI FREE ELECTRON LASER
A. D. Brynes∗
Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy
Abstract
A systematic study of microbunching instability is being
carried out in the FERMI free-electron laser linac driver.
This contribution will report about modelli... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 0 |
8db67f92-a6d5-44a4-915f-b44af842ad37 | energy spread ( <0.1%) in the case of the latter [1,2]. One
ofthemostsignificantfactorsthatcanpreventtheelectron
beamfrommeetingtheserequirementsisthemicrobunching
instability[3 –5], acollectiveinteractionthatcancausean
increaseinthesliceenergyspreadoftheelectronbunch,and
a highly non-uniform current profile [6,7]. Bot... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 0 |
3e29a1ed-1ecf-4501-811b-e139ec0fc650 | beam can be reduced by controlling the longitudinal disper-
sionandtransverseopticsinthelinac-to-FELtransferline
(alternatively known as the spreader).
THEORY
Examplesofthecollectiveeffectsthatcandrivethemi-
crobunching instability at medium-to-high energies in an
FEL are coherent synchrotron radiation (CSR) [11,12], g... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 0 |
f11caba9-c290-4370-b683-e2b79812db25 | Intheabsenceofcollectiveeffects,thefinalbunchingfactor
is given by:
∗alexander.brynes@elettra.eu𝑏𝑓(𝑘)=𝑏𝑖(𝑘0)exp
−1
2 𝑘𝑓𝑅56𝜎𝛿,02
×
exp
−1
2𝑘2
𝑓"
𝜖𝑥,𝑖𝛽𝑥,𝑖
𝑅51−𝛼𝑥,𝑖
𝛽𝑥,𝑖𝑅522
−𝜖𝑥,𝑖
𝛽𝑥,𝑖𝑅2
52#!
.(1)
the𝑅5xparameters givethe linear componentsof the 6×6
transfer matrix [19], and 𝜖,𝛽a... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 0 |
d1fc360f-6a48-4d05-8970-342dba68e594 | asthedispersioninvariant,givenbytheterminthesquare
bracketsofthesecondexponentialterminEq.1. Thestan-
dard method employed at a number of short-wavelength
FEL facilities is to increase the initial energy spread 𝜎𝛿,0,
throughtheuseofa‘laserheater’ [8,25 –27]. Thisdevice,
placed in the low-energy ( ≈100–300MeV) section... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 0 |
b6bc4a1d-da4b-4f8c-a00e-3decd6966e5a | demonstratedtheimportanceofthistechniqueforimproving
FELperformance,andtheyareregularlyemployedduring
the operation of these facilities.
However,thereareotherpossibleroutestoreducing 𝑏𝑓,
namely through the linear transfer matrix terms 𝑅51,𝑅52
and𝑅56. As will be shown below, through controlling these
terms in the s... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 0 |
90bcd240-220d-40f9-b601-d4c02d9d2330 | cally,anditiscalibratedsuchthattheverticalpositionofthe
streaked electrons is correlated with their longitudinal posi-
tioninthebunch,providingameasurementofthecurrent
profile of the bunch. The bending magnet acts as a spec-
trometer, and thereforeby imaging the electron bunch after
the magnet, a full measurement of th... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 1 |
d3984a1f-0a24-4fe9-87ed-320f8ca88e60 | be employed [7] – see Fig.2 for an example image . This
method is an extension of the ‘standard’ 1D analysis which
takes only the current profile of the bunch. The benefit
of performing the analysis in two dimensions is that the
modulationsinbothenergyandcurrentcanbecharacterised
simultaneously, along with the interpla... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 1 |
c290db13-7c2a-4a80-9fd7-c0663aa9aee3 | the infrared range as the electron beam passes through it,
depending on the wavelength of modulations present in the
longitudinal profile of the beam. This CTR is directed onto
aCaF2prism,whichactsasaspectrometer,andtheIRpulse
can then be sent to one of two monitors: a pyrodetector and
aPbSedetector,bothofwhichcanbeuse... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 1 |
3cc51150-886b-4986-a737-92621e08f4ad | This informed the choice of detectors; neither are able to
covertheentirerange,butbyusingbothofthemformultiple
measurements,itispossibletocharacterisethestrengthof
modulationsinthebunchacrosstheentireregionofinterest.
More details on the system are to be given in Ref. [30].
Initial commissioning results can be seen in ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 1 |
a26bf203-22be-4dfa-9e77-05fbc2708202 | involves chirping the initial laser pulse, sending it through a
Michelson interferometer with a variable delay on one arm,
and recombining the pulses in order to achieve a laser pulse
with a wavelength ranging from tens to hundreds of µm. By
impinging this laser pulse on the electron beam in the laser
heater, modulatio... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 1 |
73097c62-9ea7-41e1-bc0b-6ff2baf40b92 | Figure 3: Schematic of the infrared spectrometer (SPIR).
Theelectronbeampassesthroughanaluminiumfoil,gen-
eratingcoherenttransitionradiation(CTR)intheinfrared
range. This is then dispersed in a CaF 2prism, and is re-
flectedbyasphericalmirrorontoeitherofthetwodetectors
–apyrodetectorandaPbSedetector. Bothoftheseareplac... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 2 |
3884c102-53c0-4970-ad83-2be7565db4a3 | oftheresultspresentedheredemonstratetheabilityofthe
SPIRtoprovideusefulinformationonthemicrobunching
wavelength and intensity in the electron beam.
Figure5: MeasurementsoftheSPIRintensityforelectron
bunches that had modulations imposed on them in the laser
heaterthroughtheuseofthechirped-pulsebeatingtechnique
[31,32]. ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 2 |
759be2b4-af03-4619-abc4-c62eca55a2c8 | theeffectsofCSR[34];however,experimentswithanon-
isochronousspreader |𝑅56|>0[35]demonstratedthatthe
phase-mixingeffectduetoanon-zerolongitudinaldisper-
sion,whichdampsthemicrobunchinggain,canhaveamore
positiveimpact onthe FEL performancethan thereduced
CSR-inducedemittancegrowththatcanbeobtainedwhen
the𝑅56is zero.
Du... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 2 |
8f42b7b4-5708-47b2-924b-f06c9e21f8d9 | Figure6: FELbrightness(totalsignalintensityoverFWHM
bandwidth)asafunctionofthelaserheaterpulseenergy,for
threevaluesofthe 𝑅56inthespreader: 0(orange),+3mm
(blue) and−3mm (green). Image taken from Ref. [35]
of the central wavelength FWHM), respectively. Both of
thesefiguresrepresentscansofthelaserheaterpulseenergy
for ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 3 |
91e73bc9-72ac-412f-a0a1-89e5041a752f | signalasafunctionofthelaserheaterpulseenergy,forthree
valuesofthe 𝑅56inthespreader;thecolourschemeisthe
same as Fig.6. Image taken from Ref. [35]ThisimprovementinFELperformancecanalsobeseen
whenlookingtothespectraforthethreesettingsof 𝑅56at
twovaluesofthelaserheaterpulseenergy,asshowninFig.8.
The phase-mixing for pos... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 3 |
41afd2d5-338a-4ba6-a92b-f6f3bc90a532 | to damp the microbunching instability.
Figure8: AveragedFELspectrumforthreesettingsofthe
𝑅56in the spreader, with two different laser heater pulse
energies. Image taken from Ref. [35]
Transverse Optics Control
Further sets of experiments were performed in which the
dispersion invariant H𝑥was varied along thespreader ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 3 |
a99758ae-81ef-46c7-98f0-e52ebd1076c9 | spreader were calculated first by measuring the emittance
using a single-quad scan at the exit of the linac [37], then
readinginthequadrupolestrengthsalongthespreaderline
and tracking forward using the OCELOT code [38].
The first set of experiments were performed on FEL1,
which does not have access to the SPIR; therefo... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 3 |
f6821eb5-b1a3-4f34-a458-38cc6ca4b2c5 | Figure 9: Average number of peaks in the FEL spectrum for
two differenttransverse optics settingsin thespreader,as a
function of the laser heater attenuator (i.e. pulse energy);
the nominal settings lead to max (H𝑥)≈75, whereas the
modifiedopticshasmax (H𝑥)≈160. Theerrorbarsrepre-
sent the standard error per step.
th... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 4 |
5a7097f5-6d96-4254-a794-a4e484bde8db | settings lead to max (H𝑥)≈5, whereas the modified optics
has max(H𝑥)≈11. The error bars represent the standard
error per step.
Furtherconfirmationoftheexpectedsuppressionofthe
microbunching gain through increasing H𝑥was observed
on the FEL2 line; in this case, we can look to the FEL in-
tensity, as seen in Fig.10. F... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 4 |
3817183f-a074-483a-a13d-1f67b24a0b44 | inferred from these measurements are given in Fig.11, in
whichtheSPIRwavelengthwasscannedforthetwospreader
optics configurations. Deeper analysis is required, however,
in order to confirm this inference.
Figure 11: Integrated intensity of the SPIR as a function of
IRwavelengthforthesameopticsshowninFig.10;thelaser
heat... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 4 |
245b5fe5-00a6-4bf6-aa6a-48452d163822 | ments have shown that the microbunching content can be
reduced, and the FEL performance improved, by control-
ling the longitudinal and transverse optics of the electron
bunch in the spreader line. These results have provided a
path towards new methods for microbunching mitigation,
potentiallyleadingtofurtherimprovemen... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 4 |
30225270-770e-4b74-8a9d-ed43f0d92d6d | REFERENCES
[1]P. Schmüser, M. Dohlus, J. Rossbach, and C. Behrens. Free-
electron lasers in the ultraviolet and x-ray regime . Springer,
2014.
[2]Z. Huang and K.-J. Kim. Phys. Rev. ST Accel. Beams ,
10:034801, 2007.
[3]R. Akre et al. Phys. Rev. ST Accel. Beams , 11:030703, 2008.
[4]S.DiMitriandS.Spampinati. Phys. Rev. ... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 5 |
9389cb14-5f1c-4337-a7b3-b8a5f266281a | 5:074401, 2002.
[13]Z. Huang et al. Proceedings of PAC’03, Portland, OR, USA ,
2003.
[14]J. B. Rosenzweig et al. Nucl. Instrum. Meth. A , 393(2):376 –
379, 1997.
[15]E.L. Saldin, E.A. Schneidmiller, and M.V. Yurkov. Nucl.
Instrum. Meth. A , 490(1):1, 2002.
[16]E. L. Saldin, E. A. Schneidmiller, and M. V. Yurkov. Nucl.
... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 5 |
8b891ad9-39cb-4718-a720-cce931631aea | [23] C.-Y. Tsai et al. Phys. Rev. Accel. Beams , 23:124401, 2020.
[24]B. Li and J. Qiang. Phys. Rev. Accel. Beams , 23:014403, Jan
2020.
[25] J. Lee et al. Nucl. Instrum. Meth. A , 2016.
[26]S. Spampinati et al. Phys. Rev. ST Accel. Beams , 17:120705,
2014.
[27]M. Hamberg et al. Proceedings of FEL’17, Santa Fe, NM,
USA... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 5 |
e25263e8-f049-4e83-8204-d3d25f800de4 | Lett., 110:054801, 2013.
[35] G. Perosa et al. Phys. Rev. Accel. Beams , 23:110703, 2020.
[36] P. R. Ribič et al. Nat. Photon. , 13:555, 2019.
[37] M. G. Minty and F. Zimmermann. Springer, 2003.
[38] I. Agapov et al. Nucl. Instrum. Meth. A , 768:5, 2014.
[39]A. D. Brynes et al. Proceedings of FEL’22, Trieste, Italy ,
2... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2.pdf | 5 |
3bd54dca-06d3-4885-a235-4d283bc42284 | alexander.brynes@elettra.eu
IPAC 2023, Venice, Italy, 7 –12 May 2023
Characterisation of Microbunching
Instability at the FERMI Free Electron Laser
1Alex Brynes
Elettra
-
Sincrotrone Trieste | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2_talk.pdf | 0 |
0ac5219e-1386-459a-811b-29d2268e9d48 | alexander.brynes@elettra.eu
IPAC 2023, Venice, Italy, 7 –12 May 2023
Trieste Yesterday
2 | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2_talk.pdf | 1 |
a3e374a6-59a7-412b-861d-5ea8e1783504 | alexander.brynes@elettra.eu
IPAC 2023, Venice, Italy, 7 –12 May 2023
Contents
3
1)Causes and Consequences of Microbunching
2)How to Measure Microbunching
3)New Methods of Microbunching reduction via
Optics Control.
4)Conclusions & Future Work | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2_talk.pdf | 2 |
101915fa-7dd5-4095-8bb4-9af3f1a83ebb | alexander.brynes@elettra.eu
IPAC 2023, Venice, Italy, 7 –12 May 2023
Causes and Consequences of
Microbunching
4
Consequences
Microbunching instability increases the beam
energy spread and causes sidebands and pedestals
in the spectrum of a free electron laser (FEL):
Lower intensity
Wider bandwidth
Causes
Imp... | d:\Daily_ihep\Weekly Progress Report\20260425\41_IPAC'23\MOOG - MC07.1 - Accelerator Technology and Sustainability (Contributed)\MOOG2_talk.pdf | 3 |
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