Radiation Hardened Opto-atomic Magnetometer

EPIR Inc- will develop radiation hardened infrared focal plane array detectors for use in high radiation environments, specifically subject to high doses of neutrons- Such detectors are not commercially available, although radiation hardness have been requirements for specialized DOD and NASA detector applications, and are needed for future DOE applications such as in next generation rare isotope beam facilities- Numerous applications include improved performance, space-based sensors for surveillance, weather monitoring, planetary science, and missile defense- Non-space applications of radiation hard cameras include remote monitoring of nuclear reactor facilities (routine operation or accident mitigation), and high altitude aircraft- We believe that our technical approaches will result in detectors better in radiation hardness than the state of the art, at much lower cost and higher availability- HgCdTe-based detectors with CdTe passivation are generally accepted to be the most radiation hard infrared detector technology, and has seen prominent use in high radiation applications-1,2 Irradiation causes progressive degradation of devices, which can be minimized by detector design and follow a predictable profile over the life of the system- For HgCdTe (having 5 µm cutoff wavelength), we have recently demonstrated of material-level stability of ~10µs lifetimes under 100 krad(Si) 63 MeV proton irradiation,3 as well as device-level stability under 30 krad(Si) using commercial read out integrated circuits (ROICs)-Weexpect device performance degradation can be mitigated by optimizing the geometry of the pixel cell to reduce the effect of radiation-induced changes in carrier diffusion length- Such geometry optimization is one thrust of our proposed effort- Another key contribution to radiation damage is in the read out integrated circuit (ROIC)- Typical commercial ROICs suffer significant performance degradation after receiving dose of >30 krad(Si) protons- Such radiation damage testing with high energy protons is typical for screening devices for space applications, but we expect damage effects to be qualitatively similar for neutrons- Our collaborator, Black Forest Engineering, has developed a ROIC that is radiation hard by design, having 40 µm pixel pitch and 260x256 array size- Their engineering team has provides us with all the necessary specifications to design an initial mask set for an FPA compatible with their design- It is anticipated that the combination of our novel FPA pixel cell design, combined with the Black Forest ROIC will result in state-of-the-art radiation hardness, including low probability of single event faults in the readout- Black Forest is currently developing a 1k x 1k radiation hard CTIA (capacitive trans- impedance amplifier) readout with 15um pitch, and we expect it will be available to us in the timeframeof a Phase II SBIR-