Superconducting nanowires as high-rate photon detectors in strong magnetic fields

Superconducting nanowire single photon detectors are capable of single-photon detection across a large spectral range with near unity detection efficiency, picosecond timing jitter, and sub-10 mu m position resolution, at rates as high as 10(9) counts/s. In an effort to bring this technology into nuclear physics experiments, we fabricate niobium nitride (NbN) nanowire detectors using ion beam assisted sputtering and test their performance in strong magnetic fields. We demonstrate that these devices are capable of detection of 400 nm wavelength photons with saturated internal quantum efficiency at temperatures of 3 K and in magnetic fields of up to 5 T at high count rates and with nearly zero dark counts.