Detectors and detector control system design and performance for the SuMIRe Prime Focus Spectrograph (PFS) cameras

Abstract

We discuss the design, construction, and performance of the detector system for the SuMIRe Prime Focus Spectrograph (PFS). SuMIRe PFS is a massively multi-plexed ground-based spectrograph consisting of four identical spectrograph modules, each receiving roughly 600 fibers from a 2394 fiber robotic positioner at the prime focus. Each spectrograph module has three channels covering the wavelength ranges 3800 angstrom-6400 angstrom, 6400-9550 angstrom. and 9550-12600 angstrom, with the dispersed light being imaged in each channel by a f/1.07 vacuum Schmidt camera. In this paper we describe the CCD system for the two visible channels and the overall control and data acquisition systems for the cameras, and discuss the test system for detector characterization. This system will also serve for testing the H4RG infrared detectors for the near IR channel. The first red system, utilizing a 200-micron thick fully depleted p-channel Hamamatsu CCD, is finished and has been tested. The performance is excellent, with low noise, high CTE, and very good low-level and overall linearity. The test system uses essentially all the ‘flight’ electronics and power supplies, in an effort to assess performance in an environment as nearly like the one to be seen in operation as possible.