  Currently, many detector technologies for thermal neutron detection are in
development in order to lower the demand for the rare 3He gas. Gas detectors
with solid thin film neutron converters readout by gas proportional counter
method have been proposed as an appropriate choice for applications where large
area coverage is necessary. In this paper, we investigate the probability for
gamma-rays to generate a false count in a neutron measurement. Simulated
results are compared to measurement with a 10B thin film prototype and a 3He
detector. It is demonstrated that equal gamma-ray rejection to that of 3He
tubes is achieved with the new technology. The arguments and results presented
here are also applicable to gas detectors with converters other than solid 10B
layers, such as 6Li layers and 10BF3 gas.
