At present, study of the novel Compton telescope with high sensitivity has great scientific significance. The calorimeter, as one of the important components of the Compton telescope, is required to have excellent energy resolution and position resolution. For this purpose, a CsI(Tl) $\gamma $-ray detector of dual-ended readout based on silicon photomultipliers (SiPM) was designed as the basic detection unit of the calorimeter for the Compton telescope. Different wrapping materials (Teflon, Tyvek and ESR) and different crystal sizes (5 mm×5 mm×60 mm, 5 mm×5 mm×80 mm and 5 mm×5 mm×100 mm) were used to construct the detectors, and the detectors were tested with a ¹³⁷Cs source. The influence of the wrapping materials was not significant to the energy resolution but quite pronounced to the light attenuation length and position resolution. Besides, the light attenuation length and position resolution showed strong correlation, i.e. the shorter light attenuation length corresponding to the better the position resolution; In addition, for the three detectors using different sizes of the crystals, they did not show significant differences in performance. Eventually, the CsI(Tl) crystal detector with the size of 5 mm×5 mm×80 mm and the wrapped with ESR was determined to construct the detector satisfied with the requirements of the calorimeter for the novel Compton telescope. The energy resolution can reach 5.2% and the position resolution is about 5.2 mm.

In this work, a compact phoswich detector consisting of a cylindrical LaBr₃(Ce) principal crystal and a well-shaped CsI(Tl) sub-crystal was designed and assembled to identify and reject Compton scattering in the LaBr₃(Ce). Two different crystals coupled to the same photomultiplier tube (PMT). The energy deposition in each layer from incident radiation is then determined via digital pulse shape analysis of the PMT’s pulses. The results of Geant4 simulations were used to verify the performance of the pulse shape identification and the effect of Compton background suppression. Experimental tests were conducted on the detector prototype using a ⁶⁰Co gamma source, and the result shown that the detector background suppression coefficient was 2.33(1) which achieved the expected purpose of twice as much as the Compton background was suppressed.

The nucleus ²⁸S (isospin projection $ T_{Z}=-2 $) near the proton drip-line was produced, separated and purified by HIRFL-RIBLL1 facility and the measurement of $\beta$-delayed $\gamma$ decay of ²⁸S was performed using a detector array consisted of double-sided silicon detectors and Clover-type high purity germanium detectors. Five $\gamma$ transitions from $\beta$ decay of ²⁸S were precisely measured and the corresponding energies of the states of daughter ²⁸P were obtained. The branch ratios of low-lying states of ²⁸P populated by $\beta$ decay were extracted for the first time and the new partial ²⁸S $\beta$-decay scheme was deduced. This work provides accurate data for the further study of mirror asymmetry in ²⁸S/²⁸Mg.