Water Recovery X-Ray Rocket grating spectrometer

Abstract

The Water Recovery X-Ray Rocket (WRXR) was a suborbital rocket payload that was launched and recovered in April 2018. The WRXR flew two technologies being developed for future large x-ray missions: x-ray reflection gratings and a hybrid CMOS detector (HCD). The large-format replicated gratings on the WRXR were measured in ground calibrations to have absolute single-order diffraction efficiency of ∼60%, ∼50%, and ∼35% at CVI, OVII, and OVIII emission energies, respectively. The HCD was operated with ∼6 e − read noise and ∼88 eV energy resolution at 0.5 keV. The WRXR was also part of a two-payload campaign that successfully demonstrated NASA sounding rocket water recovery technology for science payloads. The primary instrument, a soft x-ray grating spectrometer, targeted diffuse emission from the Vela supernova remnant over a field-of-view >10 deg 2 . The flight data show that the detector was operational during flight and detected x-ray events from an on-board calibration source, but there was no definitive detection of x-ray events from Vela. Flight results are presented along with a discussion of factors that could have contributed to the null detection.

Expected Gamma-Ray Burst Detection Rates and Redshift Distributions for the BlackCAT CubeSat Mission

“…The mission's scientific instrument is a coded-aperture X-ray telescope with an array of four X-ray hybrid CMOS detectors (HCDs) in the detector plane. A similar X-ray HCD was flown on the Water Recovery X-Ray Rocket mission in 2018 (Miles et al 2019); BlackCAT will provide the detectors' first use on a satellite. Validating and characterizing the long-term in-space performance of Speedster-EXD550 HCDs is the primary technology-development driver for BlackCAT.…”

X-ray verification of sol-gel resist shrinkage in substrate-conformal imprint lithography for a replicated blazed reflection grating

“…The silicon master was tested without a reflective overcoat whereas the inverted SCIL replica was coated with a thin layer of gold to avoid modification of the sol-gel resist by the incident beam, and moreover, to provide a surface with tabulated data for index of refraction and high reflectivity at a 1.7 • grazing-incidence angle. This layer was sputter-coated on the replica in an identical fashion to Miles, et al [2]: 5 nm of chromium was deposited for adhesion followed immediately by 15 of gold, without breaking vacuum. Because this thickness is several times larger than the 1/e penetration depth in gold at grazing-incidence angles, it is justified to treat this top film as a thick slab in this context [6,26].…”

“…Packaged equipment that automates spin-coating and this pneumatic-based SCIL wafer-scale imprint method for high-volume replication has been developed by Philips SCIL Nanoimprint Solutions [14]. This production platform, known as A SCIL, was first applied to x-ray reflection grating technology for the grating spectrometer on board the Water Recovery X-ray Rocket [12,15], which utilized 26 nickel-coated replicas of a 110 cm 2 master grating fabricated through crystallographic etching in a manner similar to the processing described by Miles, et al [2].…”

REX: X-ray experiment on the water recovery rocket

“…The spectrometer consisted of a mechanical collimator, X-ray reflection gratings, grazing incidence mirrors, and a hybrid CMOS detector. In-depth description of the mission goals and the WRXR payload can be found in [12][13][14][15].…”