skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA

Abstract

The rf photocathode gun and the solenoid for the SPARC project at INFN-LNF (Frascati) have been fabricated and undergone initial testing at UCLA. The advanced aspects of the design of these devices are detailed. Final diagnosis of the tuning of the RF gun performance, including operating mode frequency and field balance, is described. The emittance compensating solenoid magnet, which is designed to be tuned in longitudinal position by differential excitation of the coils, has been measured using Hall probe scans for field profiling, and pulsed wire methods to determine the field center. Comparisons between measurements and the predictions of design codes are made.

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
875806
Report Number(s):
SLAC-PUB-11640
TRN: US0600796
DOE Contract Number:
AC02-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: Contributed to Particle Accelerator Conference (PAC 05), Knoxville, Tennessee, 16-20 May 2005
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; DESIGN; DIAGNOSIS; EXCITATION; PERFORMANCE; PHOTOCATHODES; PROBES; SOLENOIDS; TESTING; TUNING; UCLA; Accelerators,ACCPHY, ACCSYS

Citation Formats

Rosenzweig, J.B., Cook, A.M., Dunning, M.P., Frigola, P., Travish, G., /UCLA, Sanelli, C., Tazzioli, F., /Frascati, Palmer, D.T., and /SLAC. RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA. United States: N. p., 2006. Web.
Rosenzweig, J.B., Cook, A.M., Dunning, M.P., Frigola, P., Travish, G., /UCLA, Sanelli, C., Tazzioli, F., /Frascati, Palmer, D.T., & /SLAC. RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA. United States.
Rosenzweig, J.B., Cook, A.M., Dunning, M.P., Frigola, P., Travish, G., /UCLA, Sanelli, C., Tazzioli, F., /Frascati, Palmer, D.T., and /SLAC. Mon . "RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA". United States. doi:. https://www.osti.gov/servlets/purl/875806.
@article{osti_875806,
title = {RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA},
author = {Rosenzweig, J.B. and Cook, A.M. and Dunning, M.P. and Frigola, P. and Travish, G. and /UCLA and Sanelli, C. and Tazzioli, F. and /Frascati and Palmer, D.T. and /SLAC},
abstractNote = {The rf photocathode gun and the solenoid for the SPARC project at INFN-LNF (Frascati) have been fabricated and undergone initial testing at UCLA. The advanced aspects of the design of these devices are detailed. Final diagnosis of the tuning of the RF gun performance, including operating mode frequency and field balance, is described. The emittance compensating solenoid magnet, which is designed to be tuned in longitudinal position by differential excitation of the coils, has been measured using Hall probe scans for field profiling, and pulsed wire methods to determine the field center. Comparisons between measurements and the predictions of design codes are made.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 30 00:00:00 EST 2006},
month = {Mon Jan 30 00:00:00 EST 2006}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • The longitudinal accelerating field E. has been measured as a function of azimuthal angle in the full cell of the cold test model for the 1.6 cell BNL/SLAC/UCLA {number_sign}3 S-band RF Gun using a needle rotation/frequency perturbation technique. These measurements were conducted before and after symmetrizing the full cell with a vacuum pump out port and an adjustable short. Two different waveguide to full cell coupling schemes were studied. The dipole mode of the full cell is an order of magnitude less severe before symmetrization for the 0{theta}-coupling scheme. The multi-pole contribution to the longitudinal field asymmetry are calculated usingmore » standard Fourier series techniques. The Panofsky-Wenzel theorem is used in estimating the transverse emittance due to the multipole components of E{sub x}.« less
  • The 1.6 cell S-band photoinjector cavity has been in operation at the DUVFEL at BNL for the past year. Initial beam measurements indicated a higher than expected emittance and beam divergence at the exit of the gun. field imbalance in the two cells was suspected, but lack of field probes in the cavity prohibited direct confirmation. A detailed SUPERFISH model was constructed of the cavity assembly. Field balance as a function of cathode plate and tuner position was determined using the model. A series of calibrated measurements of both the cavity RF properties and the delivered RF power was undertaken.more » Electron beam properties were also measured as function of cavity tune. Significant improvements in beam quality were achieved. The simulations and measurements are presented.« less
  • With increasing demand for high brightness, low emittance beams for use with free-electron lasers, Compton scattering systems and wake-field accelerator experiments, stringent requirements have been placed on the design and operation of the 1.6 cell photoinjector. The proposed hybrid photoinjector combines the BNL/UCLA/SLAC style 1.5/1.6 cell standing wave gun with a traveling wave accelerator. Our goal is an injector that meets today's requirements and is scalable in design to meet tomorrow's demands: emittances in the region of 1 mm-mrad for higher brightness as well as higher currents. The hybrid photoinjector also offers higher energy operation, enhanced cost effectiveness and bettermore » scalability than current designs such as integrated PWT photoinjectors and split gun/accelerating sections. The use of both SW and TW systems allows for higher gradients (Eo = 70 MV/m) in the SW gun for effective capture at lower emittances, while the lower energy acceleration in the TW sections (Eo = 13.5 MV/m) allows generation of higher energy beams which are less sensitive to space charge effects. We note the current results of simulation of beam dynamics, {epsilon}n,x = 3 mm-mrad, an energy spread of 1.5% with beam energies of 21 MeV at currents as high as 1.2 kA. Further we explore the possibilities of scalability to higher frequencies, analysis of coupling design, present cold test preparations and simulated RF analysis of the structure.« less
  • The Muon Ionization Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with an absolute measurement accuracy of 0.1%. To measure emittances, MICE uses two solenoidal spectrometers, with Solenoid magnets designed to have 4 T fields, uniform at 3 per mil level in the tracking volumes. Magnetic field measurements of the Spectrometer Solenoid magnet SS2, and analysis of coil parameters for input into magnet models will be discussed.
  • Recent advances in the art of constructing high field superconducting magnets has made it possible to attempt experiments which would be extremely difficult if not impossible using conventional magnets. In the following summary, a super-conducting solenoid to be used in one of these new experiments is described in some detail.