High energy neutron spectrometers are being developed to measure the energy spectrum of neutrons, which are a component of the space radiation environment. Energetic neutrons are harmful to space systems and space crews in unique ways. To quantify these harmful effects it is necessary to identify the neutron component in the space radiation environment and measure its energy spectrum. The key to this measurement is identifying the neutron. We will develop new scintillating optical fiber technology that greatly improves the identification of neutron-capture signals over the current state-of-the-art. These fibers will be embedded in a large plastic scintillator to create a neutron detector. This detector will be tested in a simulated spacecraft radiation environment to demonstrate the performance of these fibers as neutron identifiers.More »
This project is developing cew scintillating optical fiber technology that greatly improves the identification of neutron-capture signals over the current state-of-the-art.More »
|Organizations Performing Work||Role||Type||Location|
|University of Alabama in Huntsville (UAH)||Lead Organization||Academia||Huntsville, Alabama|
|Johnson Space Center (JSC)||Supporting Organization||NASA Center||Houston, Texas|
The objective of this investigation is to develop a new technique for detecting neutrons in a mixed radiation environment that will enable measuring the neutron energy spectra with a compact low-power detector. The concept for the detector is shown below. This investigation supports Technology Area 06/Section 2.5- Radiation. Specifically, this investigation contributes to two points in this section: “development of higher-fidelity space radiation monitoring capabilities” and “development of small low-power active radiation instrumentation.”
The project developed optically isolated scintillation fibers that can be used within a capture gated neutron spectrometer. Overall, the optical isolation was proved to improve the gamma rejection capability of these types of sensors. However the light collection uniformity of the system was not acceptable for use in a flight detector system. The cladded fiber approach was fully investigated and can be shown to reduce unwanted background signals. The light collection efficiency issues were explored and possible solution are recommended for follow on work. It is not clear if the improved light collection efficiency will make significant enough improvements to alter the current state of the art performance.