A novel source of MeV positron bunches driven by energetic protons for PAS application

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 763; pp. 184 - 189
• Main Authors: Tan, Zongquan, Xu, Wenzhen, Liu, Yanfen, Xiao, Ran, Kong, Wei, Ye, Bangjiao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2014
• Subjects: CSNS; Fast chopper; MeV positron bunches; PAS; Proton beam; Fast chopper; CSNS; Proton beam; PAS; MeV positron bunches
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2014.05.054

This paper proposes a novel methodology of MeV positrons generation for PAS application. Feasibility of this proposal analyzed by G4Beamline and Transport have shown reasonable success. Using 2Hz, 1.6GeV, 100ns and 1.5μC/bunch proton bunches for bombarding a graphite target, about 100ns e+ bunches are generated. Quasi-monochromatic positrons in the range of 1–10MeV included in these bunches have a flux of >107/s, peak brightness of 1014/s. A magnetic-confinement beamline is utilized to transport the positrons and a “Fast Beam Chopper” is unprecedentedly extended to chop those relativistic bunches. The positron beam can be finally characterized by the energy range of 1–10MeV and bunch width from one hundred ps up to 1ns. Such ultrashort bunches can be useful in tomography-type positron annihilation spectroscopy (PAS) as well as other applications.