The applicability of ultrasonic Oxygen Deficiency Hazard detectors in the LHC accelerator tunnel

Abstract

The Large Hadron Collider (LHC), will contain about 96 tonnes of high-density helium, mostly located in the underground components of the LHC machine. Some of potential LHC cryogenic system failures might be followed by helium discharge to the tunnel and potential decrease of the oxygen concentration below the safety level of 18% cannot be excluded. A novel concept for oxygen deficiency detection can be based on measurements of sound velocity in the atmosphere. The paper presents the test results of ultrasonic ODH detection prototype system in radiation environment similar to that predicted for the LHC.Presented at the 20th International Cryogenic Engineering Conference (ICEC20) The Large Hadron Collider (LHC), will contain about 96 tonnes of high-density helium, mostly located in the underground components of the LHC machine. Some of potential LHC cryogenic system failures might be followed by helium discharge to the tunnel and potential decrease of the oxygen concentration below the safety level of 18 % cannot be excluded [1]. A novel concept for oxygen deficiency detection can be based on measurements of sound velocity in the atmosphere. The paper presents the test results of ultrasonic ODH detection prototype system in radiation environment similar to that predicted for the LHC.

Ultrasonic helium detectors applied in oxygen deficiency hazard monitor system in radiation environment

“…The prototype ultrasonic sound velocity measuring system was designed and built at Wroclaw University of Technology. The system aims to detect helium release into the air in a quantity that may cause oxygen deficiency hazard and is also dedicated to work in radiation conditions [3]. The system consists of two parts: the sound velocity measuring unit, placed directly in an irradiation area and the control unit, which can be connected to a PC.…”

“…The first part of the irradiation test was carried out at TCC2 irradiation facility in the European Organization for Nuclear Research CERN, Geneva, Switzerland [3]. The TCC2 radiation test zone is situated in the SPS (single proton synchrotron) complex at CERN.…”

“…A novel concept for oxygen deficiency detection is based on measurements of sound velocity [4,10]. The sound velocity a in a perfect gas mixture is given by the equation:…”