Performance of a cylindrical tissue equivalent proportional counter for use in neutron monitoring.
Q. Chau, T. Lahaye, S. Ménard, L. Donadille, T. Bolognese, A. Rannou, Ninth Symposium on Neutron Dosimetry, 28-09/03-10/2003, Delft.
Tissue equivalent proportional counters (TEPC) allow the measurements of the absorbed dose and the ambient dose equivalent for neutron fields. A device based on this approach has already been developed by IRSN to be used in high energy neutron fields for space applications (NAUSICAA)[[i]][[ii]]. The response of this detector underestimates significantly the dose equivalent at low energies (several hundred keV) which represent the major component of neutron fields at workplaces in the nuclear industry. A counter with a similar geometry (cylindrical detector) and a lower gas pressure was studied in order to simulate a 1 micron biological site. In 2003, the performance of the device was further improved by adding a small amount of 3He to the tissue–equivalent gas (propane based) in order to increase the response for the lower energies of neutrons. Tests were performed in monoenergetic neutron and sources fields. This paper presents the experimental results obtained with this change.