High pressure gas scintillation drift chamber with photomultipliers inside of working medium

Vibration-proof high-pressure xenon electroluminescence detector

“…Due to this circumstance, EL benefits from lower fluctuations and may support better energy resolution than the gas gain amplification process. Advantages of EL detectors in getting good energy resolution in particularly at 9-20 bar pressures have been already demonstrated [4], [5]. The goal of this work is to show that ELD are relatively insensitive to vibrations.…”

“…The cathode (2), drift electrodes (3), and the grid (4) define a sensitive volume having dimensions of . Parallel-plate photolithography-made grid electrodes (4,5) are used to generate EL that is detected by a photomultiplier (9) optically coupled to a window placed behind the grounded grid. A 0.5-layer of p-terphenyl , serving as a wavelength shifter, is vacuum-deposited on the inner surface of the optical window enabling the photomultiplier to "see" the 170-nm UV light generated during the EL process.…”

“…A 0.5-layer of p-terphenyl , serving as a wavelength shifter, is vacuum-deposited on the inner surface of the optical window enabling the photomultiplier to "see" the 170-nm UV light generated during the EL process. The quantum efficiency of the p-terphenyl wave shifter has been measured to be 90% in pressurized xenon [5]. The emission spectrum of p-terphenyl has two peaks: one at 350 and another at 450 nm.…”

“…If the energy of drifting electrons is slightly below the ionization threshold, they do not initiate charge-multiplication avalanches but rather effectively excite noble gas atoms and generate intensive electroluminescence (EL) light by the following processes For a given gas pressure, the EL process does not occur below a certain field threshold. In a uniform electric field, the number of photons, , generated by one drifting electron is proportional to the drift path [cm], the reduced electric field strength [kV/cm/bar], and the gas pressure [bar] (1) the best value of the intensity of EL has been measured to be 1700 photons/cm at in 9 bar xenon [5]. EL has been observed in all noble gases and their mixtures.…”

Vibration-proof high-pressure xenon electroluminescence detector

“…For a given gas pressure, the electroluminescence process does not occur below a certain field threshold. In a uniform electric field, the number of photons, N ph, generated by one drifting electron is proportional to the drift path x [cm], the reduced electric field strength E/p [kV/cm/bar], and the gas pressure p (1) The best value of the intensity of electroluminescence has been measured to be 1,700 photons/cm at E/p = 3.4 kV/cm/bar [4]. EL has been observed in all noble gases and their mixtures.…”