Development of Calorimetric Low-Temperature Detectors for Application in Heavy Ion Physics

微量热计检测入射粒子以热的形式沉积其动能后吸收体的温度变化。这种操作原理在能量分辨率、探测效率、能量阈值和辐射硬度方面比传统探测器具有相当大的优势。在1-100 keV的能量范围内，用微量热计检测x射线的相对能量分辨率可达1-3‰。对于重离子的直接能量灵敏探测，获得了1-7‰的相对分辨率，与传统的重离子探测器相比，提高了一个数量级。提议的艾米-诺特研究小组将开发和调整微热量计，特别是重离子物理实验的需要。其中一个重点是用于重离子直接能量敏感探测的微量热计：主要目的是研究和提高这种探测器在0.1 MeV/u以下能量范围内的性能，这一点目前还没有得到解决。应用这种探测器精确测定固体中重离子的能量损失，将为离子化、电荷交换或原子核的直接弹性散射等能量沉积机制提供重要信息。用于探测x射线的微热量计将应用于新建的离子阱设施HITRAP (Gesellschaft f<e:1> r Schwerionenforschung, Darmstadt)，通过精确测量高电荷重离子（Lamb shift）中的电子跃迁能量来探测量子电动力学。特别是对于不稳定的原子核，这种方法也为确定核电荷半径提供了另一种方法。

Microcalorimeters detect the temperature change of an absorber after an incoming particle has deposited its kinetic energy as heat. This operation principle provides considerable advantage over conventional detectors with respect to energy resolution, detection efficiency, energy threshold and radiation hardness. The detection of X-rays with microcalorimeters achieves a relative energy resolution of 1–3 ‰ in the energy regime of 1–100 keV. For the direct, energy-sensitive detection of heavy ions, a relative resolution of 1–7 ‰ has been obtained, which means an improvement of one order of magnitude as compared to conventional heavy-ion detectors.The proposed Emmy-Noether research group will develop and adapt microcalorimeters especially for the needs of heavy-ion physics experiments. One focus lies on microcalorimeters for the direct energy-sensitive detection of heavy ions: The main aim is to investigate and improve the performance of such detectors in the energy range below 0.1 MeV/u, which has not been addressed up to now. The application of such detectors for the precise determination of energy losses of heavy ions in solids will provide important information on the energy deposition mechanisms like ionization, charge exchange or the direct elastic scattering of nuclei.Microcalorimeters for the detection of X-rays will be applied at the newly constructed ion-trap facility HITRAP (Gesellschaft für Schwerionenforschung, Darmstadt) to probe Quantum Electrodynamics by precise measurements of the electron transition energies in highly-charged heavy ions (Lamb shift). Especially for unstable nuclei, this method will also open access to an alternative way to determine nuclear charge radii.