Experimental study of a crystal positron source

Chehab, R.; Cizeron, R.; Sylvia, C.; Baier, V.N.; Beloborodov, K.; Bukin, A. D.; Burdin, S.; Dimova, T.; Drozdetsky, A. A.; Druzhinin, V. P.; Dubrovin, M.; Голубев, В. Б.; Serednyakov, S. I.; Shary, V.; Strakhovenko, V. M.; Artru, X.; Chevallier, M.; Dauvergne, D.; Kirsch, R.; Lautesse, P.; Poizat, J.C.; Remillieux, J.; Jejcic, A.; Keppler, P.; Major, J.; Gatignon, L.; Bochek, G.L.; Kulibaba, V.I.; Маслов, Н.И.; Bogdanov, A.; Potylitsin, A.P.; Vnukov, I. E.

doi:10.1016/s0370-2693(01)01395-8

Cited by 37 publications

(23 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These photons can, then, materialize into e-e+ pairs in the same crystal or in amorphous converters put downstream. Theoretical studies [1] and simulations [2][3][4] were confirmed by experiments at CERN and KEK [5][6][7][8][9]. Separating the crystal-radiator from the amorphous-converter with a bending magnet in between to sweep off the charged particles, allowing only photons to impinge on the converter, presents very interesting features concerning the amount of energy deposited and for its density.…”

Section: -Introductionmentioning

confidence: 81%

A positron source using an axially oriented crystal associated to a granular amorphous converter

徐成海¹,

Chehab²,

Sievers³

et al. 2012

Chinese Phys. C

View full text Add to dashboard Cite

A non-conventional positron source using the intense γ radiation from an axially oriented monocrystal which materializes into e+e− pairs in a granular amorphous converter is described. The enhancement of photon radiation by multi-GeV electrons crossing a tungsten crystal along its <111> axis is reported. The resulting enhancement of pair production in an amorphous converter placed 2 meters downstream, is also reported. Sweeping off the charged particles from the crystal by a bending magnet upstream of the converter allows a significant reduction of the deposited energy density. Substituting a granular target made of small spheres for the usual compact one, makes the energy dissipation easier. The deposited energy and corresponding heating are analyzed and solutions for cooling are proposed. The configurations studied here for this kind of positron source allow its consideration for unpolarized positrons for the ILC.

show abstract

Section: -Introductionmentioning

confidence: 81%

A positron source using an axially oriented crystal associated to a granular amorphous converter

徐成海¹,

Chehab²,

Sievers³

et al. 2012

Chinese Phys. C

View full text Add to dashboard Cite

show abstract

“…The results [19] show that no damages occurred during these irradiations. Later on, an experiment operated at CERN (WA 103) showed significant enhancements in positron production between W crystal and amorphous targets both of the same thickness: a factor 2, for an 8 mm target and a factor 4, for 4 mm target [20,21].…”

Section: The Hybrid Target Based On Channeling Process As E + Sourcementioning

confidence: 99%

Brilliant positron sources for CLIC and other collider projects

Rinolfi

Chehab

Dadoun³

et al. 2013

Nuclear Instruments and Methods in Physics Research Section B:

View full text Add to dashboard Cite

The CLIC (Compact Linear Collider), as future linear collider, requires an intense positron source. A brief history is given up to the present baseline configuration which assumes unpolarized beams. A conventional scheme, with a single tungsten target as source of e -e + pairs, has been studied several years ago. But, in order to reduce the beam energy deposition on the e + target converter, a double-target system has been studied and proposed as baseline for CLIC. With this ''hybrid target'', the positron production scheme is based on the channeling process. A 5 GeV electron beam impinges on a thin crystal tungsten target aligned along its <111> axis, enhancing the photon production by channeling radiation. A large number of photons are sent to a thick amorphous tungsten target, generating large number of e -e + pairs, while the charged particles are bent away, reducing the deposited energy and the PEDD (Peak Energy Deposition Density). The targets parameters are optimized for the positron production. Polarized positron beams are an option for CLIC, which needs R&D. Some brilliant positron sources are briefly reviewed.

show abstract

“…More details on the unpolarized e + source are found in various publications. Experiments using crystal targets were performed at CERN [3] and at KEK [4]. The positron production efficiency was measured with an electron beam of 4 and 8 GeV.…”

Section: Generation Of Unpolarized Positronmentioning

confidence: 99%

The Clic Electron and Positron Polarized Sources

Rinolfi

Variola²,

Liu³

et al. 2011

Polarized Sources, Targets and Polarimetry

View full text Add to dashboard Cite

The CLIC polarized electron source is based on a DC gun where the photocathode is illuminated by a laser beam. Each micro-bunch has a charge of 6x10 9 e − , a width of 100 ps and a repetition rate of 2 GHz. A peak current of 10 A in the micro-bunch is a challenge for the surface charge limit of the photo-cathode. Two options are feasible to generate the 2 GHz e − bunch train: 100 ps micro-bunches can be extracted from the photo-cathode either by a 2 GHz laser system or by generating a macro-bunch using a ~200 ns laser pulse and a subsequent RF bunching system to produce the appropriate micro-bunch structure. Recent results obtained by SLAC, for the latter case, are presented. The polarized positron source is based on a positron production scheme in which polarized photons are produced by a laser Compton scattering process. The resulting circularly-polarized gamma photons are sent onto a target, producing pairs of longitudinally polarized electrons and positrons. The Compton backscattering process occurs either in a Compton ring, where a 1 GeV electron beam interacts with circularly-polarized photons in an optical resonator or in a 1.8 GeV Compton Energy Recovery Linac (ERL) or in a 6 GeV Linac with several optical cavities. The undulator scheme is also studied. The nominal CLIC e + bunch population is 6.7x10 9 particles per bunch at 200 MeV. The tradeoff between e + yield and level of polarization is an important topic. The overall scheme for both polarized electron and positron beams is described.

show abstract

Experimental study of a crystal positron source

Cited by 37 publications

References 10 publications

A positron source using an axially oriented crystal associated to a granular amorphous converter

A positron source using an axially oriented crystal associated to a granular amorphous converter

Brilliant positron sources for CLIC and other collider projects

The Clic Electron and Positron Polarized Sources

Contact Info

Product

Resources

About