Calcium fluoride for the study of Neutrinos and Dark matters by Low-energy Spectrometer (CANDLES) searches for neutrino-less double-beta decay of ⁴⁸Ca using a Ca${\mathrm{F}}_2$ scintillator array. A high Q-value of ⁴⁸Ca at 4268 keV enabled us to achieve low background, however, at the same time it causes difficulties in calibrating the detector’s Q-value region because of the absence of a standard high-energy $\gamma$-ray source. Therefore, we have developed a novel calibration system based on $\gamma$-ray emission by neutron capture on ²⁸Si, ⁵⁶Fe, and ⁵⁸Ni nuclei. In this paper, we report the development of the new calibration system as well as the results of energy calibration in CANDLES up to 9 MeV.

低能谱仪（CANDLES）用于研究中微子和暗物质的氟化钙使用Ca来寻找⁴⁸ Ca的无中微子双β衰变${\mathrm{F}}_2$闪烁体阵列。在4268 keV时⁴⁸ Ca的高Q值使我们能够获得较低的背景，但是，由于缺乏标准的高能，它同时在校准检测器的Q值区域时造成了困难$\gamma$-射线源。因此，我们开发了一种基于$\gamma$中子俘获²⁸ Si，⁵⁶ Fe和⁵⁸ Ni原子核产生的X射线辐射。在本文中，我们报告了新校准系统的开发以及在高达9 MeV的CANDLES中进行能量校准的结果。