Paper  Title  Other Keywords  Page 

MOPA25  Simulated Lorentz Force Detuning Compensation with a Double Lever Tuner on a Dressed ILC/1.3 GHz Cavity at Room Temperature  cavity, controls, flattop, SRF  106 


Pulsed SRF linacs with high accelerating gradients experience large frequency shifts caused by Lorentz force detuning (LFD). A piezoelectric actuator with a resonance control algorithm can maintain the cavity frequency at the nominal level thus reducing the RF power. This study uses a double lever tuner with a piezoelectric actuator for compensation and another piezoelectric actuator to simulate the effects of the Lorentz force pulse. A double lever tuner has an advantage by increasing the stiffness of the cavitytuner system thus reducing the effects of LFD. The tests are conducted at room temperature and with a dressed 1.3 GHz 9cell cavity.  
Poster MOPA25 [0.931 MB]  
DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022MOPA25  
About •  Received ※ 03 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 13 August 2022  
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MOPA81  Study of Nonlinear Dynamics in the 4D Hénon Map Using the Square Matrix Method and Iterative Methods  dynamicaperture, lineardynamics, lattice, sextupole  232 


Funding: Accelerator Stewardship program under award number DESC0019403 US Department of Energy, Office of Science, High Energy Physics under award number DESC0018362 and Michigan State University The Hénon Map represents a linear lattice with a single sextupole kick. This map has been extensively studied due to its chaotic behavior. The case for the two dimensional phase space has recently been revisited using ideas from KAM theory to create an iterative process that transforms nonlinear perturbed trajectories into rigid rotations*. The convergence of this method relates to the resonance structure and can be used as an indicator of the dynamic aperture. The studies of this method have been extended to the four dimensional phase space case which introduces coupling between the transverse coordinates. *Hao, Y., Anderson, K., & Yu, L. H. (2021, August). Revisit of Nonlinear Dynamics in Hénon Map Using Square Matrix Method. https://doi.org/10.18429/JACoWIPAC2021THPAB016 

Poster MOPA81 [3.103 MB]  
DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022MOPA81  
About •  Received ※ 19 July 2022 — Revised ※ 04 August 2022 — Accepted ※ 15 August 2022 — Issue date ※ 26 August 2022  
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MOPA82  Space Charge Driven Third Order Resonance at AGS Injection  experiment, emittance, spacecharge, injection  236 


Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DESC0012704 with the U.S. Department of Energy Resonance line crossings at significant space charge tune shifts can exhibit various phenomena due to periodic resonance crossing from synchrotron motion* and manifests as halo generation and bunch shortening along with the more mundane emittance growth and beam loss. An injection experiment is conducted at the AGS using the fast wall current monitor and electron collecting Ionization Profile Monitor (eIPM) to probe third order resonances to better characterize the resonance crossing over a 4 ms time scale. This experiment shows some agreement with previous experiments, save for lack of bunch shortening, possibly due to relative resonance strength. * G. Franchetti et al. PRSTAB 13, 114203. 2010 

Poster MOPA82 [1.924 MB]  
DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022MOPA82  
About •  Received ※ 02 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 19 August 2022 — Issue date ※ 24 August 2022  
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TUPA56  Beam Coupling Impedances of Asymmetric Components of the Scorpius Induction Linac  impedance, linac, dipole, vacuum  469 


The transverse beam coupling impedance of induction linacs must be minimized to avoid beam breakdown instability. The vacuum chamber of the Scorpius linac contains complicated asymmetric elements. We present calculations of the transverse impedance for three asymmetric discontinuities: (1) a pumping section between accelerating cells, which contains vacuum plenum, pumping grid, and bellows; (2) a fast flapper valve; and (3) a debris blocker at the end of the linac. The dipole transverse impedance is calculated with CST Studio using both wakefield solver and eigen solver.  
DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022TUPA56  
About •  Received ※ 01 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 06 October 2022  
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TUPA64  Analysis of Resonant Converter Topology for HighVoltage Modulators  highvoltage, operation, impedance, klystron  486 


Funding: Work Supported by the United States Department of Energy, National Nuclear Security Agency, under contract DEAC5206NA25396 At the Los Alamos Neutron Science Center (LANSCE), we are considering various topologies to replace obsolete charging supplies and capacitor banks that provide highvoltage directcurrent (DC) power to the 44, 805MHz klystron modulators that drive the LANSCE Coupled Cavity Linac (CCL). Among the possible replacement topologies is the High Voltage Converter Modulator (HVCM), originally designed at LANSCE for use at the Spallation Neutron Source (SNS), to be used as a pulsed highvoltage power supply for klystronbased RF transmitters. The HVCM topology uses high frequency transformers with resonant LC networks for efficient energy conversion and a frequency dependent gain, which permits the use of frequency modulation as a control variable to afford pulse flattening and excellent regulation as demonstrated at SNS. A mathematical analysis is presented that links the converter resonant tank components to the frequency dependent output behavior of the converter modulator. LAUR2225179 

DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022TUPA64  
About •  Received ※ 03 August 2022 — Revised ※ 10 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 22 August 2022  
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WEYE3  Improvements to the Recycler/Main Injector to Deliver 850 kW+  proton, booster, operation, experiment  578 


The Main Injector is used to deliver a 120 GeV high power proton beam for Neutrino experiments. The design power of 700 kW was reached in early 2017 but further improvements have seen a new sustained peak power of 893 kW. Two of the main improvements include the shortening of the Main Injector ramp length as well optimizing the slipstacking procedure performed in the Recycler to reduce the amount of uncaptured beam making its way into the Main Injector. These improvements will be discussed in this paper as well future upgrades to reach higher beam powers.  
Slides WEYE3 [24.715 MB]  
DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022WEYE3  
About •  Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 18 August 2022  
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WEPA49  FerriteFree Circulator for Precise Measurements of SRF Cavities with High QFactor  ISOL, cavity, SRF, experiment  742 


Funding: This work was supported by the US Department of Energy, Offices of High Energy and Nuclear Physics, awards DESC0020926 and DESC0022439. In this work, we suggest and investigate new magnetless circulators based on three resonators connected in a loop and parametrically modulated in time with mutual phase lag. The first design consists of three Fano resonators with a spectrally asymmetric response, in contrast to schemes based on the Lorentz resonators explored thus far. The second design includes three FanoLorentz resonators, i.e., it also possesses spatial asymmetry. We demonstrate that the asymmetric approach provides strong and reversible isolation for the practically feasible modulation amplitude and rate. The results of our work are promising for precise measurements of superconducting radio frequency cavities with high Qfactor. 

DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022WEPA49  
About •  Received ※ 04 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 13 September 2022  
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WEPA74  Characterization of Fully Coupled Linear Optics with TurnbyTurn Data  optics, lattice, coupling, quadrupole  805 


Funding: This research used resources of the NSLSII, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DESC0012704. In the future diffractionlimited light source rings, fully coupled linear optics to generate round beams is preferable. While machine tune approaching to linear difference resonances, small random errors, such as quadrupole rolls, can result in fully coupled optics. Consequently, some uncertainty exists in such optics due to random errors distributions. Given beam position monitors turnbyturn readings, the harmonic analysis method was used to characterize the coupled Ripken Twiss parameters. 

Poster WEPA74 [0.889 MB]  
DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022WEPA74  
About •  Received ※ 25 July 2022 — Revised ※ 30 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 19 August 2022  
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WEPA80  Progress on Convergence Map Based on Square Matrix for Nonlinear Lattice Optimization  lattice, dynamicaperture, storagering, lineardynamics  823 


Funding: DOE. We report progress on applying the square matrix method to obtain in high speed a "convergence map", which is similar but different from a frequency map. We give an example of applying the method to optimize a nonlinear lattice for the NSLSII upgrade. The convergence map is obtained by solving the nonlinear dynamical equation by iteration of the perturbation method and studying the convergence. The map provides information about the stability border of the dynamical aperture. We compare the map with the frequency map from tracking. The result in our example of nonlinear optimization of the NSLSII lattice shows the new method may be applied in nonlinear lattice optimization, taking advantage of the high speed (about 30~300 times faster) to explore x, y, and the offmomentum phase space. 

Poster WEPA80 [5.392 MB]  
DOI •  reference for this paper ※ doi:10.18429/JACoWNAPAC2022WEPA80  
About •  Received ※ 19 July 2022 — Revised ※ 26 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 10 August 2022  
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