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Title Generation of gamma ray beams with tunable energy by annihilation of positrons in flight
Authors R. Abrams,Andrei Afanaciev,Charles Ankenbrandt,Kevin Beard,Slawomir Bogacz,L. Campbell,James Fast,G. Flanagan,Rolland Johnson,D. Neuffer,M. Popovic,C. Yoshikawa
JLAB number JLAB-ACP-11-1356
LANL number (None)
Other number DOE/OR/23177-1559
Document Type(s) (Journal Article) 
Supported by U.S. Naval Research: No
Supported by Jefferson Lab LDRD Funding: No

Compiled for Physical Review Special Topics AB
Publication Abstract: Design concepts are presented for a system to produce beams of nearly monoenergetic gamma rays tunable in an energy range around 10 MeV. The gamma rays are produced in the forward direction by annihilation in flight of nearly monoenergetic positrons. The positrons are produced by an electron beam impinging on a target subsystem optimized for positron production within the acceptance of the downstream subsystems. The target is followed by an innovative ?dipole plus wedge? monochromator, in which the positrons are bent 180° in a uniform magnetic field to disperse their momenta, after which a wedge absorber selectively reduces their momentum spread to a narrow range. Those positrons then impinge on a low-Z converter plate in which some of them annihilate with atomic electrons in the converter to produce the desired gamma ray beam. Simulations using G4Beamline (which in turn uses Geant4) have been performed to verify the concepts and to evaluate the system performance.
Experiment Numbers: other
Group: Ctr for Adv Stud of Accel
Document: pdf
Accepted Manuscript:
Supporting Documents:
Supporting Datasets: