High-accuracy measurement of the emission spectrum of liquid xenon in the vacuum ultraviolet region

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2015-09, Vol.795, p.293-297
• Main Authors: Fujii, Keiko, Endo, Yuya, Torigoe, Yui, Nakamura, Shogo, Haruyama, Tomiyoshi, Kasami, Katsuyu, Mihara, Satoshi, Saito, Kiwamu, Sasaki, Shinichi, Tawara, Hiroko
• Format: Article
• Language: English
• Subjects: Emission spectrum; Liquid xenon; Photon counting; Scintillator
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2015.05.065

The emission spectrum of cryogenic liquid xenon in the vacuum ultraviolet region was measured by irradiating liquid xenon with gamma-rays from a radioactive source. To achieve a high signal-to-noise ratio, we employed coincident photon counting. Additionally, the charge of the photo-sensor signals was measured to estimate the number of detected photons accurately. In addition, proper corrections were incorporated for the wavelength; response functions of the apparatus obtained using a low-pressure mercury lamp, and photon detection efficiencies of the optical system were considered. The obtained emission spectrum is found to be in the shape of a Gaussian function, with the center at 57,199±34 (stat.)±33 (syst.)cm−1 (174.8±0.1 (stat.)±0.1 (syst.)nm) and the full width at half maximum of 3328±72 (stat.)±65 (syst.)cm−1 (10.2±0.2 (stat.)±0.2 (sys.)nm). These results are the most accurate values obtained in terms of the data acquisition method and the calibration for the experimental system and provide valuable information regarding the high-precision instruments that employ a liquid-xenon scintillator.