Two-Stage Cryogenic HEMT Based Amplifier For Low Temperature Detectors

• Main Authors: Anczarski, J, Dubovskov, M, Fink, C. W, Kevane, S, Kurinsky, N. A, Mazumdar, A, Meijer, S. J, Phipps, A, Ronning, F, Rydstrom, I, Simchony, A, Smith, Z, Thomas, S. M, Watkins, S. L, Young, B. A
• Format: Journal Article
• Language: English
• Published: 26-01-2024
• Subjects: Physics - High Energy Physics - Experiment; Physics - Instrumentation and Detectors
• DOI: 10.48550/arxiv.2311.02229

J. Low Temp. Phys. 214, 256 (2024) To search for dark matter candidates with masses below $\mathcal{O}$(MeV),
the SPLENDOR (Search for Particles of Light dark mattEr with Narrow-gap
semiconDuctORs) experiment is developing novel narrow-bandgap semiconductors
with electronic bandgaps on the order of 1-100 meV. In order to detect the
charge signal produced by scattering or absorption events, SPLENDOR has
designed a two-stage cryogenic HEMT-based amplifier with an estimated charge
resolution approaching the single-electron level. A low-capacitance ($\sim$1.6
pF) HEMT is used as a buffer stage at $T=10\,\mathrm{mK}$ to mitigate effects
of stray capacitance at the input. The buffered signal is then amplified by a
higher-capacitance ($\sim$200 pF) HEMT amplifier stage at $T=4\,\mathrm{K}$.
Importantly, the design of this amplifier makes it usable with any insulating
material - allowing for rapid prototyping of a variety of novel detector
materials. We present the two-stage cryogenic amplifier design, preliminary
voltage noise performance, and estimated charge resolution of 7.2 electrons.