Online measurement of the intensity of keV positron beam. (June 2020)

• Record Type: Journal Article
• Authors: Zhang, Z.Y.; Wu, Y.; Liang, S.; Ke, Z.X.; Xia, X.G.; Wang, B.Y.; Zhang, P.
• Is Part Of: Radiation physics and chemistry. Volume 171(2020:Jun.)
• Publication Date: 2020-06
• Subjects: Slow positron beam -- Online measurement -- Beam intensity -- Monte Carlo simulation; Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2020.108698
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: The intensity of keV positron beam generated by 22 Na slow positron beam device is weak (generally less than 10 6 e + /s). Therefore, the traditional method of obtaining beam intensity by Faraday cup is no longer applicable. Currently published methods of obtaining beam intensity are relatively deficient and insufficient. In this paper, a new method was developed to obtain the real-time intensity of positron beam, that is, the HPGe detector was used to collect the 511-keV photons emitted from the thick target bombarded by the positrons, combining with the experimental calibration value of HPGe detector for 511-keV photons as a 22 Na standard point source placed at the collision point of thick carbon target, and with the relevant parameters got by Monte Carlo simulation. Moreover, the method our group developed and the corrected method of others were both applied for online measurement of beam intensity of 4–9 keV positrons colliding with the pure thick targets (Al, Zn, Nb and Pb). Through comparative analyses, the method our group developed could measure positron beam intensity online more accurately. Highlights: A new method was developed to obtain the real-time intensity of positron beam generated by 22 Na slow positron beam device. The intensity of the positron beam generated by the 22 Na slow positron beam device might fluctuate greatly. For different atomic number targets, our method is reasonable and feasible for obtaining beam intensity.