Since the International Commission on Radiological Protection has issued in Publication 60 new recommendations on radiation protection quantities, there is increasing interest in commercially available instruments optimized and calibrated for the measurement of neutron ambient dose equivalent H*(10) (Conversion factors as published in ICRP74).

Therefore the neutron doserate meter LB6411 was designed in a joint cooperation between BERTHOLD and the Forschungszentrum Karlsruhe GmbH. The detector system with integrated electronics has a patented He-3 proportional counter tube centered in a moderator sphere with diameter 250mm. The geometrical arrangement was optimized with the help of extensive MCNP Monte-Carlo calculations and is patented too.

The instrument has an extremely high sensitivity of approximately 3 counts per nSv and can be used both as portable instrument or as a stationary monitor. Fluence responses have been measured in monoenergetic neutron beams at the Physikalisch-Technische Bundesanstalt in Braunschweig, Germany.

• Calibrated to neutron ambient dose equivalent H* (10) according to ICRP74
• Neutron detection from thermal energies up to 20 MeV
• Energy dependency +/- 30% between 50 keV and 10 MeV

Extremely high sensitivity and therefore low measuring times in weak neutron fields.