AI 中文总结
该研究研制出一款20g重的无翼型薄接触ICPC HPGe探测器，其在77K下漏电流为皮安级、耗尽电压约440V，能量分辨率优异，实现稳定亚皮法运行，验证了无翼薄接触设计的可行性。
AI 中文摘要
采用薄非晶锗（a-Ge）接触的高纯度锗（HPGe）探测器可实现双极电荷阻挡与表面钝化，同时最小化接触相关的非活性厚度。我们报道了一种p型倒置同轴点接触（ICPC）HPGe探测器的研制与表征，该探测器采用薄a-Ge接触，为无翼几何结构，避免了我们此前原型所用的保护性翼结构。探测器由美国能源部（USD）生长的区熔HPGe晶体制成，质量为20.0g。在77K温度下，其表现出皮安级漏电流，工作耗尽电压约为440V。伽马射线能谱在59.5keV处的能量分辨率为1.75keV（半高全宽FWHM），在662keV处为3.19keV FWHM。经校准的电荷注入方法测得其绝对电容为0.496pF，方法级相对不确定度估计为6%至8%，与采用静电建模（使用该http URL）得到的0.488pF值一致。当将241Am源置于探测器孔内时，探测器表现出与源相关的过量电流，以及以3558keV为中心的宽化退化α连续谱，表明其对近表面相互作用具有敏感性。由于源封装、中间材料及近表面电荷收集响应未被独立表征，该连续谱无法用于推断唯一的死层厚度或能量损失机制。主要结果是成功研制出20g重的无翼薄接触ICPC原型，实现稳定的亚皮法运行。
英文摘要
High-purity germanium (HPGe) detectors with thin amorphous-germanium (a-Ge) contacts can provide bipolar charge blocking and surface passivation while minimizing contact-related inactive thickness. We report the fabrication and characterization of a p-type inverted coaxial point-contact (ICPC) HPGe detector using thin a-Ge contacts in a wingless geometry that avoids the protective wing structure used in our previous prototype. The detector was fabricated from a USD-grown, zone-refined HPGe crystal and has a mass of 20.0~g. At 77~K, it exhibited picoampere-scale leakage current and an operational depletion voltage of approximately 440~V. Gamma-ray spectroscopy yielded energy resolutions of 1.75~keV FWHM at 59.5~keV and 3.19~keV FWHM at 662~keV. The calibrated charge-injection method gave an absolute capacitance of 0.496~pF, with an estimated method-level relative uncertainty of 6--8\%, consistent with the 0.488~pF value obtained from electrostatic modeling with \texttt{SolidStateDetectors.jl}. With a $^{241}$Am source positioned inside the detector bore, the detector showed a source-correlated excess current and a broad degraded-alpha continuum centered near 3558~keV, demonstrating sensitivity to near-surface interactions. Because the source encapsulation, intervening materials, and near-surface charge-collection response were not independently characterized, the continuum is not used to infer a unique dead-layer thickness or energy-loss mechanism. The principal result is successful fabrication and stable sub-pF operation of a 20-g wingless thin-contact ICPC prototype.
Comments17 pages, 7 figures, and 3 table
