2011 Particle Accelerator Conference - Table of Session: WEODS (Accelerator Technology III)

Paper

Title

Page

Design and Optimization of Future X-ray FELs based on Advanced High Frequency Linacs

1491

F. Wang
SLAC, Menlo Park, California, USA

To drive future XFELs, normal-conducting linacs at various rf freqencies are being considered. With optimized accelerator structures and rf systems, a higher rf frequency linac has several advantages, such as high acceleration gradient and high rf-to-beam efficiency. This paper presents a comparison of possible S-band, C-band and X-band linac designs for two cases, single bunch operation and multibunch operation, where the bunch train length is longer than the structure fill time and the beam loading is small. General scaling laws for the main linac parameters, which can be useful in the design such linacs, are derived.

Slides WEODS1 [5.795 MB]

WEODS2

High-Power Targets: Experience and R&D for 2 MW

1496

P. Hurh
Fermilab, Batavia, USA
O. Caretta, T.R. Davenne, C.J. Densham, P. Loveridge
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
N. Simos
BNL, Upton, Long Island, New York, USA

High-power particle production targets are crucial elements of future neutrino and other rare particle beams. Fermilab plans to produce a beam of neutrinos (LBNE) with a 2.3 MW proton beam (Project X). Any solid target is unlikely to survive for an extended period in such an environment - many materials would not survive a single beam pulse. We are using our experience with previous neutrino and antiproton production targets, along with a new series of R&D tests, to design a target that has adequate survivability for this beamline. The issues considered are thermal shock (stress waves), heat removal, radiation damage, radiation accelerated corrosion effects, physics/geometry optimization and residual radiation.

WEODS3

CEBAF 200 kV Inverted Electron Gun

1501

J.M. Grames, P.A. Adderley, J. Clark, J. Hansknecht, M. Poelker, M.L. Stutzman, R. Suleiman, K.E.L. Surles-Law
JLAB, Newport News, Virginia, USA
M. BastaniNejad
Old Dominion University, Norfolk, Virginia, USA
J.L. McCarter
UVa, Charlottesville, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. In addition, DOE-HEP funds this work in support of the ILC R&D program.
Two DC high voltage GaAs photoguns have been built at Jefferson Lab based on a compact inverted insulator design. One photogun provides the polarized electron beam at CEBAF and operates at 130 kV bias voltage. The other gun is used for high average current lifetime studies at a dedicated test facility and has been operated at bias voltage up to 225 kV. The advantages of higher DC voltage for CEBAF include reduced space-charge emittance growth and the potential for prolonged photocathode lifetime. However, a consequence of operating at higher voltages is the increased likelihood of field emission or breakdown, both of which are unacceptable. Highlights of the R&D studies leading toward a production 200keV GaAs photogun for CEBAF will be presented.

Slides WEODS3 [1.360 MB]

WEODS4

High Gradient Normal Conducting Radio-Frequency Photoinjector System for Sincrotrone Trieste

1504

L. Faillace, R.B. Agustsson, P. Frigola
RadiaBeam, Santa Monica, USA
H. Badakov, A. Fukasawa, J.B. Rosenzweig, A. Yakub
UCLA, Los Angeles, California, USA
F. Cianciosi, P. Craievich, M. Trovò
ELETTRA, Basovizza, Italy
L. Palumbo
Rome University La Sapienza, Roma, Italy
B. Spataro
INFN/LNF, Frascati (Roma), Italy

Radiabeam Technologies is leading a multi-organizational collaboration by UCLA, INFN and MATS to deliver a high gradient normal conducting radio frequency (NCRF) 1.6 cell photoinjector system to the Sincrotrone Trieste facility. Designed to operate with a 120MV/m accelerating gradient, this dual feed, fat lipped racetrack coupler design is modeled after the LCLS photoinjector with a novel demountable cathode which permits cost effective cathode exchange. Full overview of the project to date will be discussed along with basic, design, engineering, manufacturing and RF test results.

Slides WEODS4 [3.186 MB]

Paper	Title	Page
WEODS1	Design and Optimization of Future X-ray FELs based on Advanced High Frequency Linacs	1491
	F. Wang SLAC, Menlo Park, California, USA
	To drive future XFELs, normal-conducting linacs at various rf freqencies are being considered. With optimized accelerator structures and rf systems, a higher rf frequency linac has several advantages, such as high acceleration gradient and high rf-to-beam efficiency. This paper presents a comparison of possible S-band, C-band and X-band linac designs for two cases, single bunch operation and multibunch operation, where the bunch train length is longer than the structure fill time and the beam loading is small. General scaling laws for the main linac parameters, which can be useful in the design such linacs, are derived.
	Slides WEODS1 [5.795 MB]

WEODS2	High-Power Targets: Experience and R&D for 2 MW	1496
	P. Hurh Fermilab, Batavia, USA O. Caretta, T.R. Davenne, C.J. Densham, P. Loveridge STFC/RAL, Chilton, Didcot, Oxon, United Kingdom N. Simos BNL, Upton, Long Island, New York, USA
	High-power particle production targets are crucial elements of future neutrino and other rare particle beams. Fermilab plans to produce a beam of neutrinos (LBNE) with a 2.3 MW proton beam (Project X). Any solid target is unlikely to survive for an extended period in such an environment - many materials would not survive a single beam pulse. We are using our experience with previous neutrino and antiproton production targets, along with a new series of R&D tests, to design a target that has adequate survivability for this beamline. The issues considered are thermal shock (stress waves), heat removal, radiation damage, radiation accelerated corrosion effects, physics/geometry optimization and residual radiation.

WEODS3	CEBAF 200 kV Inverted Electron Gun	1501
	J.M. Grames, P.A. Adderley, J. Clark, J. Hansknecht, M. Poelker, M.L. Stutzman, R. Suleiman, K.E.L. Surles-Law JLAB, Newport News, Virginia, USA M. BastaniNejad Old Dominion University, Norfolk, Virginia, USA J.L. McCarter UVa, Charlottesville, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. In addition, DOE-HEP funds this work in support of the ILC R&D program. Two DC high voltage GaAs photoguns have been built at Jefferson Lab based on a compact inverted insulator design. One photogun provides the polarized electron beam at CEBAF and operates at 130 kV bias voltage. The other gun is used for high average current lifetime studies at a dedicated test facility and has been operated at bias voltage up to 225 kV. The advantages of higher DC voltage for CEBAF include reduced space-charge emittance growth and the potential for prolonged photocathode lifetime. However, a consequence of operating at higher voltages is the increased likelihood of field emission or breakdown, both of which are unacceptable. Highlights of the R&D studies leading toward a production 200keV GaAs photogun for CEBAF will be presented.
	Slides WEODS3 [1.360 MB]

WEODS4	High Gradient Normal Conducting Radio-Frequency Photoinjector System for Sincrotrone Trieste	1504
	L. Faillace, R.B. Agustsson, P. Frigola RadiaBeam, Santa Monica, USA H. Badakov, A. Fukasawa, J.B. Rosenzweig, A. Yakub UCLA, Los Angeles, California, USA F. Cianciosi, P. Craievich, M. Trovò ELETTRA, Basovizza, Italy L. Palumbo Rome University La Sapienza, Roma, Italy B. Spataro INFN/LNF, Frascati (Roma), Italy
	Radiabeam Technologies is leading a multi-organizational collaboration by UCLA, INFN and MATS to deliver a high gradient normal conducting radio frequency (NCRF) 1.6 cell photoinjector system to the Sincrotrone Trieste facility. Designed to operate with a 120MV/m accelerating gradient, this dual feed, fat lipped racetrack coupler design is modeled after the LCLS photoinjector with a novel demountable cathode which permits cost effective cathode exchange. Full overview of the project to date will be discussed along with basic, design, engineering, manufacturing and RF test results.
	Slides WEODS4 [3.186 MB]