UV-sensitive superconducting nanowire single photon detectors for   integration in an ion trap
  We demonstrate superconducting nanowire single photon detectors with 76 +/- 4 % system detection efficiency at a wavelength of 315 nm and an operating temperature of 3.2 K, with a background count rate below 1 count per second at saturated detection efficiency. We propose integrating these detectors into planar surface electrode radio-frequency Paul traps for use in trapped ion quantum information processing. We operate detectors integrated into test ion trap structures at 3.8 K both with and without typical radio-frequency trapping electric fields. The trapping fields reduce system detection efficiency by 9 %, but do not increase background count rates. 
D. H. Slichter, V. B. Verma, D. Leibfried, R. P. Mirin, S. W. Nam, and   D. J. Wineland
quant-ph cond-mat.supr-con physics.ins-det physics.optics