Neutron measurements using the 3He-Ne laser

New neutron detection methods using the 3He-Ne lasing are explained. These methods are mainly based on two types of lasing: Nuclear Pumped Laser (NPL) and Radiation Triggered Laser (RTL). In the NPL mode, the charged particles produced by neutron reactions directly excite the laser gas, and then the lasing occurs. The direct NPL output power and the optical gain are available as signals to measure the thermal neutron flux. In the RTL mode, the neutron irradiation raises the discharge of the laser gas when a specific voltage is applied, and then the lasing occurs. This method is based on the variation of the lasing voltage by the neutron irradiation. (author)