Performance Measurements of the Flight Detector for SPICE on SolarOrbiter

Abstract:

The Spectral Imaging of the Coronal Environment (SPICE) instrument for the
Solar Orbiter mission will make spectroscopic observations of the Sun's low
corona to characterize the plasma properties of the source regions of the solar
wind. The detector package for SPICE, provided by the NASA Goddard Space
FLight Center, consists of two microchannel-plate (MCP) intensified Active
Pixel Sensor (APS) detectors covering the short (702-792 Angstroms) and long
(972-1050 Angstroms) wavelength bandpasses. The long wavelength detector will
also provide coverage in second order between 485-525 Angstroms. We previously
reported on measurements of the engineering model detector. Here, we report on
measurements made on the flight SPICE detector in the same vacuum tank facility
at the Rutherford Appleton Laboratory in Harwell, UK. These measurements
include the detector flat field, sensitivity, resolution, linearity, and
statistical noise. A krypton resonance lamp operating at 1236 Angstroms was
used to stimulate the detector. Results at this wavelength are combined with
the quantum efficiency measurements of the individual MCPs at this and other
wavelengths covering the entire wavelength range to provide a complete
calibration curve for the instrument. A calibrated NIST photodiode was used to
determine the absolute brightness of the lamp.