9 papers
Process Development and First Cryogenic Operation of Compact Germanium Ring-Contact HPGe Prototypes
Kunming Dong, Shasika Panamaldeniya, Dongming Mei
Rare-event experiments such as LEGEND-1000 require high-purity germanium (HPGe) detectors with excellent energy resolution, low electronic noise, and scalable low-background packag…
Internal Charge Amplification in Germanium at 77K and 4K: From Single-Free-Flight Bounds to a Physics-Informed Ionization Model
Dongming Mei, Kunming Dong, Narayan Budhathoki +2
Internal charge amplification (ICA) in cryogenic high-purity germanium (HPGe) can lower detection thresholds by providing gain inside the detector crystal, but reliable operation r…
Fabrication and Characterization of p-type Inverted Coaxial Point Contact (ICPC) Detectors with a-Ge Dual-Blocking Contacts
S. A. Panamaldeniya, K. M. Dong, D. M. Mei
We report the fabrication and characterization of two p-type inverted coaxial point contact (ICPC) high-purity germanium (HPGe) detectors, SAP16 and SAP17, produced from USD-grown…
Hybrid-Contact Planar HPGe Process Vehicle Toward Ring-Contact Designs
Kunming Dong, Dongming Mei, Shasika Panamaldeniya +3
Rare-event searches including dark matter, coherent elastic neutrino--nucleus scattering (CENS), and neutrinoless double-beta decay (0) require high-purity germanium (HPGe)…
Evaluating the Effective Segregation Coefficient in High-Purity Germanium (HPGe) Crystals for Ge Detector Development in Rare-Event Searches
S. Chhetri, D. -M. Mei, S. Bhattarai +5
The performance and scalability of rare-event physics experiments depend on large-volume, detector-grade high-purity germanium (HPGe) crystals with precise control of impurity segr…
Probing low-mass dark matter from sub-MeV to sub-GeV with germanium-based quantum phononic spectroscopy
D. -M. Mei, N. Budhathoki, S. A. Panamaldeniya +5
We present a germanium phonon-to-charge transducer that integrates a slow-phonon phononic-crystal (PnC) region with radio-frequency quantum point-contact (RF-QPC) readout at 4 K, a…