Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers

Abstract

We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2-6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ∼20% quantum efficiency at 2.6 keV with ∼190 eV resolution and a 100 kHz maximum detection rate. The detector platform's useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry.

A compact dispersive refocusing Rowland circle X-ray emission spectrometer for laboratory, synchrotron, and XFEL applications

“…45 The detector is based on a commercial amateur astronomy camera (ZWO Company) that we have modified by removing the glass from its image sensor (Sony IMX-291), allowing x-rays to directly illuminate the sensor's active region. The camera's CMOS sensor has a pixel pitch of 2.9-µm and a 1936 × 1096 pixel layout.…”

“…In the majority of events, however, the charge cloud spreads over a cluster of several adjacent pixels. 45,46 To include all events while preserving optimal energy resolution, we have developed software to identify such clusters and reconstruct corresponding photon energies and positions. 45,46,55 With this additional processing, the sensor's quantum efficiency (QE) and energy resolution are 65% and 150 eV, respectively, at the photon energy of P Kα.…”

“…45,46 To include all events while preserving optimal energy resolution, we have developed software to identify such clusters and reconstruct corresponding photon energies and positions. 45,46,55 With this additional processing, the sensor's quantum efficiency (QE) and energy resolution are 65% and 150 eV, respectively, at the photon energy of P Kα. The quantum efficiency of the sensor decreases considerably above 4 keV, 46 leading us to focus here on the 2-2.5 keV energy range where the Si 111 optic and camera performance are synergistic.…”

“…45,46 These sensors, including the back-illuminated sensor used in the present instrument, can have pixels below 3-µm pitch while also having useful spectroscopic capability in the 2-5 keV energy range. At least moderately small pixels are necessary if fine energy resolution is to be maintained for the tightly curved Bragg optic, and the sensitivity to the energy of each recorded incident photon allows for very high rejection of background signals, minimizing the need for internal shielding.…”

A color x-ray camera for 2–6 keV using a mass produced back illuminated complementary metal oxide semiconductor sensor

“…That being said, the use of massproduced CMOS image sensors in the x-ray regime has been explored in prior literature that has established them as viable spectroscopic imaging detectors having a favorable combination of low cost (a consequence of chip-level integration of all sensor functions), high framerates, and improved radiation hardness relative to comparable charge coupled devices (CCDs). [37][38][39][40][41] By "spectroscopic," we mean that the camera output contains sufficient information for the determination of both the energy and position of a photoabsorbed x-ray. Such devices are often referred to as "color x-ray cameras."…”