[en] The C-ADS Inject-I test facility is under construction in IHEP. An interlock system based on redundancy PLC is developed for machine protection and personnel safety. Device status, radiation dose, temperature of cavities and chambers are collected for machine state judge and interlock . A MPS (Machine Protection System) are working together with the interlock system in the control loop, and protect the machine in Four levels for different situations. (author)

[en] Highlights: •We investigate the effects of swift heavy-ion irradiation on He bubbles. •Growth in size and decrease of number density upon Ar-ion irradiation were found. •The mean size of extended defects increases upon Ar-ion irradiation. •Strong electronic excitation during Ar-ion irradiation produces athermal annealing at room temperature. -- Abstract: Cross-sectional transmission electron microscopy (XTEM) was used to study the effects of irradiation with swift heavy ions on helium-implanted silicon. 〈1 0 0〉-oriented silicon wafers were implanted with 30 keV helium to a dose of 3 × 10¹⁶ He⁺/cm² at 600 K. Subsequently, the helium-implanted Si wafers were irradiated with 792 MeV argon ions. The He bubbles and extended defects in the wafers were examined via XTEM analysis. The results reveal that the mean diameter of the He bubbles increases upon Ar-ion irradiation, while the number density of the He bubbles decreases. The microstructure of the He bubbles observed after Ar-ion irradiation is comparable to that observed after annealing at 1073 K for 30 min. Similarly, the mean size of the extended defects, i.e., Frank loops, increases after Ar-ion irradiation. Possible mechanisms are discussed

[en] The effects of annealing temperature on strain and mechanical property changes of 6H-SiC implanted with helium ions at 600 K to doses of 3 × 10¹⁵ cm⁻², 1 × 10¹⁶ cm⁻² and 3 × 10¹⁶ cm⁻² and at an ion energy of 100 keV were investigated by using high-resolution X-ray diffraction (XRD), nano-indentation and transmission electron microscopy (TEM). Strain increases with increasing displacements per atom (dpa). Strain relaxation in terms of changes in Δd/d exhibited a linear decrease with increasing annealing temperature ranging from 873 K to 1473 K for 30 min in vacuum. The relaxation activation energies of the strains were estimated by Arrhenius law to be in the range of 0.4–0.7 eV. Irradiation-induced hardening was observed via nano-indentation measurements as a function of annealing. The hardness of the highly damaged layer decreased monotonically with increasing annealing temperature for the samples implanted with He ions to doses of 3 × 10¹⁵ cm⁻² and 1 × 10¹⁶ cm⁻², and where no helium bubbles were formed in the damaged layer. The hardness of the damaged layer initially decreased and then increased with increasing annealing temperature from 600 K to 1073 K for the sample implanted He ions to a dose of 3 × 10¹⁶ cm⁻², where numerous helium bubbles were formed in the damaged layer. The TEM results suggest that the growth of helium bubbles emits interstitials upon annealing. These interstitials agglomerate into stacking faults and dislocation loops, which increase the hardness

[en] In-flight calibration is crucial to monitor possible variations of detector performances, especially the polarimetric response, in Polarimetry Focusing Array (PFA) onboard the enhanced X-ray Timing and Polarimetry (eXTP) observatory. A physics-based model is established in this work to perform a quantitative simulation of the in-flight calibration sources, utilizing the GEANT4 toolkit. The physics of Bragg diffraction is implemented, derived from the scattering theory, and validated by the experimental measurements in terms of the diffraction efficiency and the degree of polarization. The extended physics process provides spectral characteristics and polarization states of emitted X-rays with reasonable accuracy. It is expected to play an important role in advancing further development of the instrument. Additionally, it enables the integration of multiple instrument simulations within the already existing framework of GEANT4, which facilitates the study of the space mission.

[en] Highlights: •Solid phase epitaxial growth of amorphous 6H-SiC was investigated. •Recrystallization initially nucleates and grows at the interface between the amorphous layer and 6H-SiC substrate. •Recrystallization rate is related to the implantation-induced damage and concentration of He impurity. •The region of recrystallization contains 3C-SiC and 6H-SiC with different crystalline orientations. -- Abstract: Solid phase epitaxial growth of amorphous 6H-SiC created by 15 keV He ion implantation to doses of 1.5 × 10"1"6, 5 × 10"1"6 and 1 × 10"1"7 cm"−"2 at room temperature (RT) followed by annealing ranging from 600 °C to 900 °C for 30 min was investigated. The recrystallization process was investigated via cross-sectional transmission electron microscopy (XTEM). Recrystallization initially nucleates and grows at the interface between the amorphous layer and 6H-SiC substrate. In the middle of the amorphous layer, recrystallization nucleation is inhibited. Recrystallization rate is related to the implantation-induced damage and concentration of He impurity. The Fourier transformed images denote that the region of recrystallization contains 3C-SiC and 6H-SiC with different crystalline orientations. Besides, for the 1 × 10"1"7 cm"−"2 implanted sample, partial areas are kept amorphous in the damaged layer. The threshold temperature of full recrystallization of He ion-implantation-induced amorphization in 6H-SiC and the previous observations on other ions implantation, such as Ne, Ar, Xe etc is compared. The possible reasons are discussed

[en] We report the formation of β'-Gd₂(MoO₄)₃ (GMO) crystal on the surface of the 21.25Gd₂O₃-63.75MoO₃-15B₂O₃ glass, induced by 250 kHz, 800 nm femtosecond laser irradiation. The morphology of the modified region in the glass was clearly examined by scanning electron microscopy (SEM). By micro-Raman spectra, the laser-induced crystals were confirmed to be GMO phases and it is found that these crystals have a strong dependence on the number and power of the femtosecond laser pulses. When the irradiation laser power was 900 mW, not only the Raman peaks of GMO crystals but also some new peaks at 214 cm^-1, 240 cm^-1, 466 cm^-1, 664 cm^-1 and 994 cm^-1which belong to the MoO₃ crystals were observed. The possible mechanisms are proposed to explain these phenomena.