A description of how self-powered neutron detectors, wide range fission chambers, flux wires,
and photographic film detect radiation is summarized below.
Miscellaneous Detector Summary
Self-powered neutron detector
The central wire, made of a neutron-absorbing material, absorbs a neutron and
undergoes beta decay.
As more beta decays occur, the remaining atoms cause the wire to become more
The voltage potential set up causes a current flow in a resistor, which is
measured by either a millivoltmeter or electrometer.
Wide range fission chamber
Neutrons interact with the U235 coated chamber causing fission of the U235.
A highly positive charged fission fragment interacts with the detector gas and
The electrons produced are collected as pulses on the electrode.
The wire is inserted directly into the core and becomes activated by the neutron
When the desired activation time is reached, the wire is removed from the core
Detects total radiation dose by darkening; film darkness determines overall
Fast neutron exposure determined by counting individual proton recoil tracks.