Spectrometers for recording electromagnetic showers emerging from oriented crystals

Low-Energy Electron Detection by Total-Absorption Cherenkov Spectrometer

“…Energy characteristics of the calibration electron beam were determined, in addition to other methods, by a total absorption Cherenkov spectrometer (TAChS) based on the lead glass TF-1 with the thickness of 14.8 radiation lengths X 0 (X 0 = 2.5 cm, ρ = 3.86 g/cm 3 ) [3][4][5].…”

“…In order to determine energy characteristics of the calibration beam, a TAChS is used that was very successful in previous works with the secondary electron beam of the proton accelerator of the Institute for High Energy Physics (IHEP) in Protvino [4,5]. The built TAChS is a hexagonal radiator of the lead glass TF-1 with the inscribed circle diameter 18 cm and length 37 cm (Fig.…”

“…On all sides, except for the area occupied by a PMT photocathode, the radiator is wrapped in an aluminized lavsan. The TAChS uses PMT-49 with a standard divider [3][4][5]. In the insert: S1 and S2 are scintillation counters.…”

“…Deterioration in the TAChS resolution in this energy region is probably associated with an increase in fluctuations of photoelectrons on the PMT photocathode that in turn is associated with insufficient amount of Cherenkov light due to a decrease in the number of shower tracks at low energies of electrons. Calibration of this TAChS at electron beams of energies of tens of GeV determined its energy resolution (without taking into account the energy resolution of the electron beam which, at an average electron pulse of 31 GeV/c, was equal to √DE =0.72 GeV/c, where DE is the dispersion of electron energy in the primary beam) [4,5] ΔE/E = 0.015 + 0.125/√E.…”