The new remcounter LB6411: measurement of neutron ambient dose equivalent H*(10) according to ICRP60 with high sensitivity

Since the International Commission on Radiological Protection, in publication ICRP60, has issued new recommendations on radiation protection quantities, there is now increasing interest in commercially available instruments optimized and calibrated for the measurement of neutron ambient dose equivalent H*(10). Therefore within a joint cooperation agreement between the Research Center Karlsruhe and EG&G Berthold, the new neutron-dose-rate meter LB6411 was developed. The detector system with integrated electronics has a /sup 3/He proportional counter tube centered in a moderating sphere. The response between thermal energies and 20 MeV was optimized with the help of extensive MCNP Monte-Carlo calculations. The instrument has an extremely high sensitivity of approximately 3 counts per nSv and can be used both as a portable or as a stationary neutron monitor. Fluence responses have been measured in monoenergetic neutron beams provided by the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, Germany. The ambient dose equivalent response of the LB6411 is reported over the whole energy range.