High‐resolution x‐ray spectroscopy with the EBIT Calorimeter Spectrometer

The EBIT Calorimeter Spectrometer (ECS) is a production‐class 36 pixel x‐ray calorimeter spectrometer that has been continuously operating at the Electron Beam Ion Trap (EBIT) facility at Lawrence Livermore National Laboratory for almost 2 years. The ECS was designed to be a long‐lifetime, turn‐key spectrometer that couples high performance with ease of operation and minimal operator intervention. To this end, a variant of the Suzaku/XRS spaceflight detector system has been coupled to a low‐maintenance cryogenic system consisting of a long‐lifetime liquid He cryostat, and a closed cycle, 3He pre‐cooled adiabatic demagnetization refrigerator. The ECS operates for almost 3 weeks between cryogenic servicing and the ADR operates at 0.05 K for more than 60 hours between automatic recycles under software control. Half of the ECS semiconductor detector array is populated with mid‐band pixels that have a resolution of 4.5 eV FWHM, a bandpass from 0.05–12 keV, and a quantum efficiency of 95% at 6 keV. The other ha...