Heat Sinking and Crosstalk for Large, Close-Packed Arrays of Microcalorimeters

We have studied crosstalk on our 8×8 transition-edge sensor (TES) x-ray microcalorimeter arrays. The shapes of thermal crosstalk pulses are well reproduced as a convolution of heat input from the source pixel and decay in the receiver pixel. We have measured the amount of thermal crosstalk as a function of distance between the source and receiver pixels. Using the results, we have estimated the degradation of energy resolution due to the thermal crosstalk as a function of count rate to determine the level of thermal crosstalk that is needed to satisfy the requirements of NASA’s Constellation-X mission.