The Zeeman splitting effect is observed in a strong magnetic field generated by a laser-driven coil. The expanding plasma from the coil wire surface is concentrated at the coil center and interacts with the simultaneously generated magnetic field. The Cu I spectral lines at wavelengths of 510.5541, 515.3235, and 521.8202 nm are detected and analyzed. The splittings of spectral lines are used to estimate the magnetic field strength at the coil center as ∼31.4 ± 15.7 T at a laser intensity of ∼5.6 × 10¹⁵ W/cm², which agrees well with measurements using a B-dot probe. Some other plasma parameters of the central plasma disk are also studied. The temperature is evaluated from the Cu I spectral line intensity ratio, while the electron density is estimated from the Stark broadening effect.

提出一种基于BCD工艺用于检测微弱光信号的单光子雪崩光电二极管（SPAD）及前端淬灭-复位电路（QRC）。为减小边缘击穿的风险，提高响应度，设计了一种圆形P+/Nwell/Deep Nwell结构SPAD，Deep Nwell和衬底之间形成的pn结，能够有效减少p衬底流向雪崩区的暗电流，降低暗计数率，也保证了较小的纵向渡越时间，提高了响应速度。同时设计了P阱保护环，增大了器件的击穿电压。采用silvaco对器件进行二维仿真，与传统的P+/Nwell结构以及P+/Nwell/BNwell结构进行了比较，验证了设计结构在击穿电压、响应度方面的优越性。为实现光电探测器与集成电路的协同设计，改进了APD光电器件的等效电路模型并在此基础上设计了主动淬灭复位电路，死时间约为2.6 ns，能够达到快速探测的目的。测试结果表明，P+/Nwell/DNwell结构的雪崩击穿电压为15.8 V，在过电压为0.2 V时，650 nm光照射下，响应度约为0.80 A/W，暗计数率为20 kHz。

In this paper, we present a reanalysis of the silicon He-$\mathrm{\alpha}$ X-ray spectrum emission in Fujioka et al.’s 2009 photoionization experiment. The computations were performed with our radiative-collisional code, RCF. The central ingredients of our computations are accurate atomic data, inclusion of satellite lines from doubly excited states and accounting for the reabsorption of the emitted photons on their way to the spectrometer. With all these elements included, the simulated spectrum turns out to be in good agreement with the experimental spectrum.

实验室天体物理是交叉于高能量密度等离子体物理学与天体物理学之间的一个新的学科生长点。利用强激光装置可以在实验室创造与某些天体或天体周围相似的极端物理环境，这样的实验条件前所未有，且与天体物理中诸多重要的物理现象直接对应。通过近距、主动、参数可控的研究，实验室天体物理有助于解决目前天体物理和等离子体物理中的一些关键的、共性的问题，并有望取得突破性成果。针对近年来国内外在该领域取得的最新研究进展进行介绍，并就将来可能开展的研究方向进行展望。

Astrophysical collisionless shocks are amazing phenomena in space and astrophysical plasmas, where supersonic flows generate electromagnetic fields through instabilities and particles can be accelerated to high energy cosmic rays. Until now, understanding these micro-processes is still a challenge despite rich astrophysical observation data have been obtained. Laboratory astrophysics, a new route to study the astrophysics, allows us to investigate them at similar extreme physical conditions in laboratory. Here we will review the recent progress of the collisionless shock experiments performed at SG-II laser facility in China. The evolution of the electrostatic shocks and Weibel-type/filamentation instabilities are observed. Inspired by the configurations of the counter-streaming plasma flows, we also carry out a novel plasma collider to generate energetic neutrons relevant to the astrophysical nuclear reactions.

Laser-driven magnetic reconnection (LDMR) occurring with self-generated B fields has been experimentally and theoretically studied extensively, where strong B fields of more than megagauss are spontaneously generated in high-power laser–plasma interactions, which are located on the target surface and produced by non-parallel temperature and density gradients of expanding plasmas. For properties of the short-lived and strong B fields in laser plasmas, LDMR opened up a new territory in a parameter regime that has never been exploited before. Here we review the recent results of LDMR taking place in both high and low plasma beta environments. We aim to understand the basic physics processes of magnetic reconnection, such as particle accelerations, scale of the diffusion region, and guide field effects. Some applications of experimental results are also given especially for space and solar plasmas.

As a promising new way to generate a controllable strong magnetic field, laser-driven magnetic coils have attracted interest in many research fields. In 2013, a kilotesla level magnetic field was achieved at the Gekko XII laser facility with a capacitor–coil target. A similar approach has been adopted in a number of laboratories, with a variety of targets of different shapes. The peak strength of the magnetic field varies from a few tesla to kilotesla, with different spatio-temporal ranges. The differences are determined by the target geometry and the parameters of the incident laser. Here we present a review of the results of recent experimental studies of laser-driven magnetic field generation, as well as a discussion of the diagnostic techniques required for such rapidly changing magnetic fields. As an extension of the magnetic field generation, some applications are discussed.

We present laboratory measurement and theoretical analysis of silicon K-shell lines in plasmas produced by Shenguang II laser facility, and discuss the application of line ratios to diagnose the electron density and temperature of laser plasmas. Two types of shots were carried out to interpret silicon plasma spectra under two conditions, and the spectra from 6.6 ? to 6.85 ? were measured. The radiative-collisional code based on the flexible atomic code (RCF) is used to identify the lines, and it also well simulates the experimental spectra. Satellite lines, which are populated by dielectron capture and large radiative decay rate, influence the spectrum profile significantly. Because of the blending of lines, the traditional $G$ value and $R$ value are not applicable in diagnosing electron temperature and density of plasma. We take the contribution of satellite lines into the calculation of line ratios of He-$\unicode[STIX]｛x1D6FC｝$ lines, and discuss their relations with the electron temperature and density.