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

微量热计检测进入的粒子将其动能转化为热量后吸收体的温度变化。这种工作原理在能量分辨率、探测效率、能量阈值和辐射硬度方面提供了优于常规探测器的显著优点。在1-100 keV的能量范围内，用微量热计探测X射线可达到1-3 ‰的相对能量分辨率。对于重离子的直接、能量灵敏探测，相对分辨率达到1-7 ‰，这意味着比传统的重离子探测器提高了一个数量级。拟议中的Emmy-Noether研究小组将开发和改造特别适合重离子物理实验需要的微量热计。一个焦点在于用于重离子的直接能量敏感探测的微量热计：主要目的是研究和改善这种探测器在低于0.1 MeV/u的能量范围内的性能，这到目前为止还没有得到解决。利用这种探测器精确测定重离子在固体中的能量损失，将提供有关电离、电荷交换或原子核直接弹性散射等能量沉积机制的重要信息。（Gesellschaft für Schwerionenforschung，达姆施塔特）通过精确测量高电荷重离子中的电子跃迁能量（兰姆位移）来探测量子电动力学。特别是对于不稳定核，这种方法也将打开一个替代的方式来确定核电荷半径。

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.