The FISCHERSCOPE X-RAY XDL with proportional counter tube, XDAL with PIN detector, or XDV- SDD with SDD detector are all available from Fischer Instrumentation (GB) Ltd.
Table 1: Various types of detectors and their corresponding achievable standard deviations and variation coefficients 50 nm Gold Detector type Standard Coefficient deviation of variation Proportional counter tube (0,2 mm aperture) 2,2 nm 4,3 % PIN detector (1 mm aperture) 0,9 nm 1,8 % SDD detector (1 mm aperture) 0,2 nm 0,4 % 24 nm Palladium Detector type Standard Coefficient deviat of variation Proportional counter tube (0,2 mm aperture) 3 nm 13 % PIN detector (1 mm aperture) 1,2 nm 4,8 % SDD detector (1 mm aperture) 0,5 nm 2,1 %
Both NCCs are based on the same type and model of thermal neutron counter tubes (3He gas-filled at 10 bar pressure, 1 inch outer diameter).
Given the global scarcity and the resulting cost of 3He gas, the 61 new counter tubes will be filled with 3He gas recovered from spare neutron counter tubes.
It is emphasised that the contract is based on the recovery and purification of 3He gas from spare counter tubes (93 pieces, with various lengths, all filled to 4 bar pressure of 3He) to produce and fill at minimum 61 new counter tubes (33 cm active length, filled to 10 bar pressure of 3He gas plus a suitable quantity of quenched gas).