Observation of time-dependent internal charge amplification in a planar germanium detector at cryogenic temperatureP. Acharya, M. Fritts, D.-M. Mei, V. Mandic, C.-J. Wang, R. Mahapatra and M. PlattEur. Phys. J. C, 83 4 (2023) 278DOI: https://doi.org/10.1140/epjc/s10052-023-11432-y