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Title: OTR measurements and modeling of the electron beam optics at the E-cooling facility

Abstract

Optics of the electron beam accelerated in the Pelletron, intended for the electron cooling of 8.9 GeV antiprotons in the Fermilab recycler storage ring, has been studied. The beam profile parameters were measured under the accelerating section using Optical Transition Radiation (OTR) monitor. The monitor employs a highly-reflective 2 inch-diameter aluminum OTR-screen with a thickness of 5 {micro}m and a digital CCD camera. The measurements were done in a pulse-signal mode in the beam current range of 0.03-0.8 A and at pulse durations ranging from 1 {micro}s to 4 {micro}s. Differential profiles measured in pulsed mode are compared with results obtained by modeling of the DC beam dynamics from the Pelletron cathode to the OTR monitor. The modeling was done with SAM, ULTRASAM and BEAM programs. An adjustment of the magnetic fields in the lenses of the accelerating section was done in the simulations. The simulated electron beam optics downstream of the accelerating section was in good agreement with the measurements made with pulsed beam.

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
878986
Report Number(s):
FERMILAB-CONF-05-465-AD
TRN: US0700931
DOE Contract Number:
AC02-76CH03000
Resource Type:
Conference
Resource Relation:
Journal Name: AIP Conf.Proc.821:380-385,2006; Conference: Presented at International Workshop on Beam Cooling and Related Topics (COOL05), Eagle Ridge, Galena, IL, USA, 18 - 23 Sep 2005
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ALUMINIUM; ANTIPROTONS; BEAM COOLING; BEAM CURRENTS; BEAM DYNAMICS; BEAM PROFILES; CATHODES; ELECTRON BEAMS; ELECTRON COOLING; MAGNETIC FIELDS; MONITORS; OPTICS; PELLETRON ACCELERATORS; STORAGE RINGS; THICKNESS; TRANSITION RADIATION; Accelerators

Citation Formats

Warner, A., Burov, Alexey V., Carlson, K., Kazakevich, G., Nagaitsev, S., Prost, L., Sutherland, M., Tiunov, M., and /Fermilab /Novosibirsk, IYF. OTR measurements and modeling of the electron beam optics at the E-cooling facility. United States: N. p., 2005. Web.
Warner, A., Burov, Alexey V., Carlson, K., Kazakevich, G., Nagaitsev, S., Prost, L., Sutherland, M., Tiunov, M., & /Fermilab /Novosibirsk, IYF. OTR measurements and modeling of the electron beam optics at the E-cooling facility. United States.
Warner, A., Burov, Alexey V., Carlson, K., Kazakevich, G., Nagaitsev, S., Prost, L., Sutherland, M., Tiunov, M., and /Fermilab /Novosibirsk, IYF. Tue . "OTR measurements and modeling of the electron beam optics at the E-cooling facility". United States. doi:. https://www.osti.gov/servlets/purl/878986.
@article{osti_878986,
title = {OTR measurements and modeling of the electron beam optics at the E-cooling facility},
author = {Warner, A. and Burov, Alexey V. and Carlson, K. and Kazakevich, G. and Nagaitsev, S. and Prost, L. and Sutherland, M. and Tiunov, M. and /Fermilab /Novosibirsk, IYF},
abstractNote = {Optics of the electron beam accelerated in the Pelletron, intended for the electron cooling of 8.9 GeV antiprotons in the Fermilab recycler storage ring, has been studied. The beam profile parameters were measured under the accelerating section using Optical Transition Radiation (OTR) monitor. The monitor employs a highly-reflective 2 inch-diameter aluminum OTR-screen with a thickness of 5 {micro}m and a digital CCD camera. The measurements were done in a pulse-signal mode in the beam current range of 0.03-0.8 A and at pulse durations ranging from 1 {micro}s to 4 {micro}s. Differential profiles measured in pulsed mode are compared with results obtained by modeling of the DC beam dynamics from the Pelletron cathode to the OTR monitor. The modeling was done with SAM, ULTRASAM and BEAM programs. An adjustment of the magnetic fields in the lenses of the accelerating section was done in the simulations. The simulated electron beam optics downstream of the accelerating section was in good agreement with the measurements made with pulsed beam.},
doi = {},
journal = {AIP Conf.Proc.821:380-385,2006},
number = ,
volume = ,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}

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  • Optics of the electron beam accelerated in the Pelletron, intended for the electron cooling of 8.9 GeV antiprotons in the Fermilab recycler storage ring, has been studied. The beam profile parameters were measured under the accelerating section using Optical Transition Radiation (OTR) monitor. The monitor employs a highly-reflective 2 inch-diameter aluminum OTR-screen with a thickness of 5 {mu}m and a digital CCD camera. The measurements were done in a pulse-signal mode in the beam current range of 0.03-0.8 A and at pulse durations ranging from 1 {mu}s to 4 {mu}s. Differential profiles measured in pulsed mode are compared with resultsmore » obtained by modeling of the DC beam dynamics from the Pelletron cathode to the OTR monitor. The modeling was done with SAM, ULTRASAM and BEAM programs. An adjustment of the magnetic fields in the lenses of the accelerating section was done in the simulations. The simulated electron beam optics downstream of the accelerating section was in good agreement with the measurements made with pulsed beam.« less
  • The use of recirculation in linear accelerator designs requires beam transport systems that will not degrade beam quality. We present a design for the transport lines to be used during recirculation in the CEBAF accelerator. These beam lines are designed to avoid beam degradation through synchrotron radiation excitation or betatron motion mismatch, are insensitive to errors commonly encountered during beam transport, and are optimized for electron beams with energies of 0.5 to 6.0 GeV. Optically, they are linearly isochronous second order achromats based on a ''missing magnet'' FODO structure. We give lattice specifications for, and results of analytic estimates andmore » numerical simulations of the performance of, the beam transport system.« less
  • The Advanced Photon Source (APS) injector complex includes an option for photocathode (PC) gun beam injection into the 450-MeV S-band linac. At the 150-MeV point, a 4-dipole chicane was used to compress the micropulse bunch length from a few ps to sub 0.5 ps (FWHM). Noticeable enhancements of the optical transition radiation (OTR) signal sampled after the APS chicane were then observed as has been reported in LCLS injector commissioning. A FIR CTR detector and interferometer were used to monitor the bunch compression process and correlate the appearance of localized spikes of OTR signal (5 to 10 times brighter thanmore » adjacent areas) within the beam image footprint. We have done spectral dependency measurements at 375 MeV with a series of band pass filters centered in 50-nm increments from 400 to 700 nm and observed a broadband enhancement in these spikes. Discussions of the possible mechanisms will be presented.« less
  • Abstract not provided.
  • Coherent Electron Cooling (CeC) requires detailed control of the phase between the hadron an the FEL-amplified wave packet. This phase depends on local electron beam parameters such as the energy spread and the peak current. In this paper, we examine the effects of local density variations on the cooling rates for CeC. Coherent Electron Cooling (CeC) [1] is a new concept in intense, high energy hadron beamcooling, in which the Debye screened charge perturbation calculated in [2] is used to seed a high-gain free electron laser (FEL). Using delays to give the perturbing hadron an energy-dependent longitudinal displacement relative tomore » its frequencymodulated charge perturbation, the hadron receives an energy-dependent kick which reduces its energy variation from the design energy. The equations of motion in [1] assume that the electron bunch is the same physical size as the hadron bunch, and has a homogeneous charge density across the entire bunch. In practice, the electron bunches will be much shorter than the hadron bunch, and this local spacial inhomogeneity in the charge distribution will alter the gain length of the FEL, resulting in both a change in the amplification of the initial signal and a phase shift. In this paper we consider these inhomogeneity effects, determining cooling equations for bunched beam CeC consistent with these effects and determining thresholds for the cooling parameters.« less