Time-division multiplexing of high-resolution x-ray microcalorimeters: Four pixels and beyond.

We present experimental results from a four-pixel array of transition-edge-sensor, x-ray microcalorimeters read out through a single amplifier channel via a time-division superconducting quantum interference device multiplexer. We map the dependence of the x-ray energy resolution of the microcalorimeters on multiplexer timing parameters. We achieve multiplexed, four-pixel resolution of 6.94±0.05 eV full width at half maximum of the Mn Kα complex near 5.9 keV, which is a degradation of only 0.44 eV from nonmultiplexed operation. An analysis of straightforward upgrades to the multiplexer predicts that a linear array of 32 of these pixels could he multiplexed with a degradation in resolution of only 0.1 eV. These results, the first demonstration of a time-division multiplexer for x-ray detectors, establish a clear path to the instrumentation of a kilopixel microcalorimeter array. [ABSTRACT FROM AUTHOR]