Monitoring of a Photon Beam

Abstract

Presented are the characteristics of systems for monitoring the intensity of the bremsstrahlung photon beam of the "Pakhra" accelerator based on Cherenkov counters.

A Scintillation Hodoscopic Spectrometer

“…The dependence in Fig. 4a qualitatively reproduces the dependence of the change in the amplitude of the 20-cm-thick scintillation spectrometer on the energy of the secondary electron beam presented in [3]. It can be seen that the energy loss in SHS increases with the electron energy up to 100 MeV and is constant at electron energies from 100 MeV to the last studied energy of 200 MeV.…”

“…HODOSCOPIC SPECTROMETER The SHS was calibrated using a quasi-monochromatic secondary-electron beam of the LPI Pakhra accelerator [4,5]. The block diagram of the calibration channel is shown in Fig.…”

“…The length of each SHS plate is 50 cm, so the mean energy loss of electrons in the scintillator is E ≈ 2 [MeV/cm] × 50 [cm] ≈ 100 MeV. Since the energy deposited in the SHS does not increase at electron energies above 100 MeV [3], the maximum energy loss in the SHS channel should also be no greater than E = E max  ≈ 100 MeV. Therefore, the first stage of calibration was carried out at the electron-beam energy E = 80 MeV.…”

“…The SHS is capable of detecting charged particles with energies in the range of up to ~80 MeV, which is two times larger than the detection range of the currently used scintillation and better with an accuracy of ≈20% relative to the spectrometer of the same type in [3]. The SHS is capable of determining the coordinate of a particle hit point at the spectrometer with an accuracy no worse than the accuracy of the scintillation hodoscope that is now located in front of the SS.…”

“…The maximum electron energy that the SS is capable of detecting is approximately E ≈ 40 MeV (E ≈ (ΔE/Δx)L, where ΔE/Δx is the mean energy loss of electrons per unit track length in the detector and L is the scintillation detector thickness [2,3]). The…”