XAMPS prototypes for the X-ray Pump Probe instruments at the LCLS

X-ray Active Matrix Pixel Sensors (XAMPS) were designed and fabricated as part of a detection system for the X-ray Pump Probe (XPP) instrument at the Linac Coherent Light Source (LCLS). XAMPS based on J-FET technology were produced on 100 mm high-resistivity silicon, typically 400 μm-thick. The prototypes are square matrices with n rows and n columns with n=16, 32, 64, 128, 256, 512. Each pixel of the matrix is 90 × 90 μm² and contains a JFET switch to control the charge readout. The small features of the design presented some technological challenges fully addressed during this production. The first prototypes were tested at the National Synchrotron Light Source (NSLS) with a monochromatic beam of 8 keV and millisecond readout and exhibit good performances at room temperature.