We present a characterization technique for nanosecond gated CMOS cameras designed and built by Sandia National Laboratory under their Ultra-Fast X-ray Imager program. The cameras have been used to record images during HED physics experiments at Sandia’s Z Facility and at LLNL’s National Ignition Facility. The behavior of the camera’s fast shutters was not expected to be ideal since they propagate over a large pixel array of 25 mm x 12 mm, which could result in shutter timing skew, variations in the FWHM, and variations in the shutter’s peak response. Consequently, a detailed characterization of the camera at the pixel level was critical for interpreting the images. Assuming the pixel’s photo-response was linear, the shutter profiles for each pixel were simplified to a pair of sigmoid functions using standard non-linear fitting methods to make the subsequent analysis less computationally intensive. A pixel-level characterization of a ”Furi” camera showed frame-to-frame gain variations that could be normalized with a gain mask and significant timing skew at the sensor’s center column that could not be corrected. The shutter profiles for Furi were then convolved with data generated from computational models to forward fit images collected with the camera.
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