Lithographically patterned magnetic calorimeter x-ray detectors with integrated SQUID readout
Barry L. Zink, Kent D. Irwin, Gene C. Hilton, David P. Pappas, Joel Ullom, Martin Huber
We describe the design, fabrication and performance of a fully lithographically patterned magnetic microcalorimeter X-ray detector. The detector is fabricated on the same chip as a low-noise SQUID which measures the change in the magnetic sensor film's magnetization as the film is heated by absorbed X-rays. Our proof-of-principle detector uses a 100 υm × 100 υm × 1.6 υm paramagnetic Au:Er film with approximately equal} 300 ppm Er spins, coupled to a low-noise on-chip SQUID via a meandering superconducting pickup loop which also provides the magnetic field bias to the film. Absorption of 6 keV x-rays in the film causes a 1 mK heating with a decay time of 200 υs. We summarize the design and fabrication of this device and present measurements of the heat capacity, decay time constant and effective thermal conductance of the microcalorimeter as a function of temperature. Because the SQUID and calorimeter are lithographically patterned on the same substrate, this technology can be readily applied to the fabrication of large-format arrays of multiplexed magnetic microcalorimeter detectors.
Nuclear Instruments & Methods in Physics Research Section A-Accelerators Spectrometers Detectors and Associated Equipment
fabrication, films, lithographically patterned, low-noise, SQUID, x-ray detectors, magnetic calorimeter
, Irwin, K.
, Hilton, G.
, Pappas, D.
, Ullom, J.
and Huber, M.
Lithographically patterned magnetic calorimeter x-ray detectors with integrated SQUID readout, Nuclear Instruments & Methods in Physics Research Section A-Accelerators Spectrometers Detectors and Associated Equipment
(Accessed December 1, 2023)