Development of space-flight room-temperature electronics for the Line Emission Mapper Microcalorimeter Spectrometer

Abstract

.We are developing space-flight room-temperature readout electronics for the Line Emission Mapper (LEM) Microcalorimeter Spectrometer (LMS) of the LEM mission. The LEM mission is an x-ray probe mission designed to study the physics of galaxy formation. The LMS is optimized for low-energy (0.2 to 2 keV) x-ray emission from extremely diffuse gas. The detector is a hybrid transition-edge sensor (TES) microcalorimeter array with a 33′ outer array and a 7 ′ × 7 ′ inner subarray. The outer array consists of 12,736 square pixels on a square grid with a 290 μm pitch but in a close-packed hexagonal shape. The inner subarray consists of 784 TES sensors arranged in a square area in the center of the outer array with the same pixel pitch. The outer array uses a sensor with 2 × 2 thermal multiplexing known as “Hydra,” and the inner array consists of a single absorber per TES. The baselined readout technology for the 3968 TES sensors is time-division multiplexing (TDM), which divides the sensors into 69 columns × 60 rows. The components of the room temperature readout electronics are the three boxes of the warm front-end electronics (WFEE) and the six boxes of the digital electronics and event processor (DEEP). The WFEE is an interface between the cold electronics and the DEEP, and the DEEP generates signals for the TDM and processes x-ray events. We present the detailed designs of the WFEE and DEEP. We also show the estimated power, mass, and size of the WFEE and DEEP flight electronics. Finally, we describe the performance of the TRL-6 prototypes for the WFEE and DEEP electronics.

Line emission mapper microcalorimeter spectrometer

“…Upon completion of these routine tests, the TRL of the WFEE will advance to TRL-6. A detailed description of the WFEE is provided by Sakai et al 60…”

“…The DEEP is therefore already considered to be at TRL-6. More detailed information about the design of the DEEP can be found in Sakai et al 60…”

Line Emission Mapper: an X-ray probe mission concept to study the cosmic ecosystems and the physics of galaxy formation

“…Details on the individual components of the LMS are discussed in detail elsewhere in this JATIS special section. [2][3][4][5][6][7] Fig. 11 (a) LEM microcalorimeter spectrometer, showing the three concentric aluminum shells, consisting of one vacuum shell and two radiation shells at 18 and 100K.…”

“…We describe the key components of the mission but defer presentation of the finer details of the LMS to other contributions in this JATIS special section. [2][3][4][5][6][7] In Sec. 2, we describe the mission, including the spacecraft design, choice of orbit, and operational modes.…”