Temperature measurement sensor using material with a temperature dependent neutron capture cross section

A temperature measurement sensor for use in a nuclear reactor, the temperature measurement sensor comprising:

• a first neutron detector member;
• and
• a second neutron detector member;
• each of the first and second neutron detector members comprising an inner electron emitter, a first layer of insulation surrounding the inner electron emitter, a charge collector surrounding the first layer of insulation, a negative charge output pin extending outwardly from the charge collector, and a positive charge output pin extending outwardly from the inner electron emitter;
• wherein the inner electron emitter of the first neutron detector member comprises a first electron emitter material;
• wherein the inner electron emitter of the second neutron detector member comprises a second electron emitter material;
• wherein the first electron emitter material and the second electron emitter material are the same;
• wherein the first neutron detector member further comprises a second layer of insulation surrounding the charge collector of the first neutron detector member, an electron absorbing layer surrounding the second layer of insulation, and an outer shield comprising an outer shield material for capturing neutrons surrounding the electron absorbing layer;
• wherein the effective neutron capture cross section of the outer shield material is temperature dependent;
• wherein in use, the first neutron detector member outputs a first current signal and the second neutron detector member outputs a second current signal;
• and
• an electrical connection between the first and second neutron detector members, the electrical connection configured to produce a difference in current between the first and second current signals, wherein the difference in current is based on the outer shield material, and wherein the difference in current is proportional to changes in temperature.