Heavy-ion storage rings are advanced large-scale nuclear physics experimental facilities that enable long-term storage and precise manipulation of accelerated heavy-ion beams. They serve as unique platforms for nuclear structure and nuclear astrophysics research. At present, the internationally representative heavy-ion storage rings in the field of nuclear physics research are: the Experimental Storage Ring (ESR) at the GSI Helmholtz Centre for Heavy Ion Research (Germany), the Cooler Storage Ring experimental ring (CSRe) at the Institute of Modern Physics, Chinese Academy of Sciences (China), and the Rare-RI Ring (R3) at the RIKEN Nishina Center (Japan). Over the past decade, researchers have conducted high-precision measurements of mass, decay lifetime, and nuclear reaction cross sections based on the aforementioned experimental platforms. Highlight experimental studies are outlined in this review, such as mass measurements of nuclei near the A = 20-70 proton drip line at CSRe, mass measurements of Pd-123 at R3, and lifetime determination of bound-state beta decay of fully stripped Tl-205(81+) and two-photon decay of Ge-72m(32+). These experimental efforts have provided crucial data for exploring the limits of nuclear existence, elucidating the characteristics of exotic nuclei, and simulating nucleosynthesis processes in astrophysical environments. The construction of the next-generation heavy-ion storage ring facility will provide superior experimental conditions for the aforementioned research endeavors, thereby facilitating advancements in nuclear physics frontier research.

The heaviest stable nuclei in the universe owe their existence to quantum shell structure, the grouping of protons and neutrons into discrete energy levels separated by gaps. The largest known neutron shell gap in stable nuclei, at N=126, stabilizes doubly-magic ^208Pb and is responsible for the characteristic abundance peak of heavy elements near gold and platinum produced by the rapid neutron-capture process (r-process). Whether this shell gap persists as protons are removed from lead is a question central to both nuclear structure and the modeling of heavy-element synthesis, yet it has remained unanswered due to the extraordinary difficulty of producing the relevant neutron-rich nuclei. Direct experimental knowledge in this region was essentially absent. Here we report the first precision mass measurements of ^203,204Pt and ^204,205,206Au, performed at GSI using a novel combination of Schottky and isochronous mass spectrometry in a heavy-ion storage ring. The N=126 isotones ^204Pt and ^205Au are more strongly bound than the extrapolated trend of the previously known mass surface by 403 and 464 keV, respectively, revealing an unexpectedly enhanced N=126 shell strength below doubly-magic ^208Pb. Furthermore, the proton-neutron interaction strength exhibits a hitherto unobserved bifurcation at N=126 as protons are removed from ^208Pb. Our results redefine the nuclear mass surface in the neutron-rich heavy-element region and provide direct experimental benchmarks for theoretical models whose extrapolations toward more exotic nuclei are essential for r-process nucleosynthesis calculations.

A deep understanding of the evolution of nuclear shell structure correlating with the nucleon number is crucial for unraveling the fundamental properties of the nuclear structure and for exploring new nuclear physics phenomena far from the β-stability line. Although significant progress has been made in probing nuclear shell evolution via the measurements of nuclear root-mean-square charge radii, R_ch, the scarcity of new data for short-lived and exotic nuclei due to the increasing difficulty of measurements presents a formidable challenge in obtaining deeper and more universal insights into the nature of shell evolution. To mitigate this issue, we develop an improved method, accounting for the exchange term, charge-symmetry breaking effect, and odd-even staggering effect in the Coulomb energy formulation compared with that proposed by Liu et al. [Phys. Lett. B 872, 140046 (2026)], to determine unmeasured R_ch values. Using the improved method, the R_ch values of 59 nuclei are determined from their measured binding energies (B) and the respective B and R_ch of their mirror partners. We then systematically study the shell evolution near N=6, 14, 20 and 28 (sub)shells by placing the newly obtained R_ch values into the corresponding isotopic chains. More comprehensive insights into the properties of nuclear shell evolution, particularly for the neutron-deficient sectors of the studied shell regions, e.g., p, sd and pf shells, are acquired, advancing our understanding of nuclear shell evolution in the light and intermediate mass region.

GRANDProto300 (hereafter referred to as GP300) is a pioneering prototype array of the GRAND experiment. It consists of 300 radio antennas and will cover an area of 200 km^2 in a radio-quiet region of western China. Serving as a test bench for the GRAND experiment, GRANDProto300 aims to achieve autonomous radio detection and reconstruction of highly inclined air showers. It is designed to detect ultra-high-energy cosmic rays in the energy range of 10^16.5-10^18 eV at a rate comparable to that of the Pierre Auger Observatory. Over the past two years, significant improvements have been made to both the hardware and firmware of GP300. Currently, 65 antenna units have been deployed at the site by June 2025. We present the current status of detector commissioning, including updates on hardware, calibration results such as GPS timing and antenna positioning. Additionally, we discuss the solar radio bursts associated with solar flares, the galactic radio emissions detected, and preliminary cosmic ray surveys.

Shell evolution is crucial for understanding nuclear structures across the nuclear chart. In this work, we employed the ab initio valence space in-medium similarity renormalization group with chiral nucleon-nucleon and three-nucleon interactions to study neutron-rich Si, S, Ar, and Ca isotopes, particularly focusing on nuclei near N = 32, 34 We systematically analyzed both neutron and proton shell evolutions by examining the excitation energies of the first 2(+) states and the effective single-particle energies. Our calculations show that the N = 32 sub-shell gradually weakens as protons are removed from the doubly magic nucleus Ca-52, eventually disappearing in Si-46. Conversely, the strength of the N = 34 sub-shell is enhanced with the removal of protons from Ca-54. Furthermore, our results indicate the existence of the proton Z = 14 sub-shell in neutron-rich Si isotopes. These findings suggest that Si-48 is a doubly magic nucleus, with the excitation energy of the first 2(+) state around 2.49 MeV, which is approximately 400 keV higher than that of Ca-54. This value is comparable to those of other well-known exotic doubly magic nuclei, such as Ca-52 and Ni-78, which is of great interest for further experiments at RIB facilities. In addition, we predicted the low-lying spectra of neutron-rich Si, S, and Ar isotopes, providing new insights for future experiments.

The recent mass measurement of 70Kr using the B rho-defined isochronous mass spectrometry yields a mass excess of-41320(140) keV, indicating a 220-keV increase in binding energy compared to the AME2020 prediction. We utilize this experimental mass-the last piece of information needed-to model the potential waiting point 68Se in rp process and quantitatively constrain the sequential p-capture reaction flow bypassing this waiting point. Our investigation shows that the more tightly bound nature of 70Kr enhances this reaction flow up to a factor of four. This enhancement reduces the effective half-life of 68Se. A one-zone x-ray burst-model calculations reveal that the higher flow of 70Kr has distinct effects on the tail structure of light curve and the final SnSbTe abundances in the ashes due to a stronger rp-process heating.

The lifetime of the isomeric state in fully stripped 94Ru44+ ions has been measured using isochronous mass spectrometry (IMS) at the experimental Cooler Storage Ring (CSRe) of the Heavy Ion Research Facility in Lanzhou (HIRFL). Previously, the isomeric lifetime was determined by analyzing the decay time points of individual decay events. In this paper, we present a novel approach to determine the isomeric lifetime based on the survival time of ions obtained from IMS. The survival lifetimes of the ground and isomeric states of 94Ru44+ were measured to be s and s in the laboratory, respectively. Given that the ground state of 94Ru44+ has a natural lifetime of approximately 75 min, its survival lifetime in the experimental setup was predominantly determined by the beam-loss lifetime, including interactions with residual gas in the storage ring and carbon foil of the detector. In contrast, the survival lifetime of 94mRu44+ was governed by its intrinsic nuclear lifetime and additional beam-loss effects. The nuclear decay lifetime of 94mRu44+ was extracted through differential survival lifetime analysis between ground and isomeric states, under the assumption that the beam-loss lifetimes for both quantum systems are identical. Using this novel methodology, the lifetime measured in the laboratory frame was s. After relativistic time-dilation corrections, the corresponding rest-frame half-life was calculated to be s. This result demonstrates excellent consistency with previous experimental results, validating the reliability of the new method. This method is suitable for determining half-lives of highly charged ions in the range of several tens of microseconds to milliseconds using IMS.

The ground-state mass excess of the T-z = -2 drip-line nucleus Al-22 is measured for the first time as 18103(10)keV using the newly-developed B rho-defined isochronous mass spectrometry method at the cooler storage ring in Lanzhou. The new mass excess value allowed us to determine the excitation energies of the two low-lying 1(+) states in Al with significantly reduced uncertainties of 51 keV. When compared to the analogue states in its mirror nucleus F-22, the mirror energy differences of the two 1(+) states in the Al-22-F-22 mirror pair are determined to be -625(51) keV and -330(51)keV. The excitation energies and mirror energy differences are used to test the state-of-the-art ab initio valence-space in-medium similarity renormalization group calculations with four sets of interactions derived from the chiral effective field theory. The mechanism leading to the large mirror energy differences is investigated and attributed to the occupation of the pi s(1/2) orbital.

The mass of neutron -deficient nuclide 58Zn has been directly measured by using Bp -defined isochronous mass spectrometry, resulting in a more precise proton separation energy of Sp(58Zn) = 2227(36) keV. With this new Sp value, the thermonuclear rate of the 57Cu(p, gamma) 58Zn reaction has been re-evaluated to be higher than the most recently published rate by a factor of up to 3 in the temperature range of 0.2 GK <= T <= 1.5 GK. The new rate is used to investigate its astrophysical impact via one -zone post -processing type -I x-ray burst calculations. It shows that the updated rate and new Sp(58Zn) value result in noticeable abundance variations for nuclei with A = 56-59 and a reduction in A = 57 abundance by up to 20.7%, compared with the results using the recently published rate.

Isochronous Mass Spectrometry is a practical approach for studying decays of short-lived isomers. However, solely relying on the time stamps between the isomer and ground state does not provide clear sign of decay. To address this issue, we proposed a method for extracting decay time point by analyzing the residuals of time stamps within a window of (20μs, 180μs) after the start of data acquisition. Decay events out of the window were disregarded due to poor accuracy of revolution time. In this paper, we propose a novel approach based on the discrete Fourier transform technique, which was tested by simulation data. We found that the accuracy of the decay time point can be improved, leading to an expanded window of (15μs, 185μs). Furthermore, as the novel method was applied to experimental data, additional five decay events were identified. The newly determined half-life of 94mRu44+ is consistent with the previous value.

The mass of neutron-deficient nuclide $^{58}\mathrm{Zn}$ has been directly measured by using $B\ensuremath{\rho}$-defined isochronous mass spectrometry, resulting in a more precise proton separation energy of ${S}_{p}(^{58}\mathrm{Zn})=2227(36)$ keV. With this new ${S}_{p}$ value, the thermonuclear rate of the $^{57}\mathrm{Cu}(p,\ensuremath{\gamma})^{58}\mathrm{Zn}$ reaction has been re-evaluated to be higher than the most recently published rate by a factor of up to 3 in the temperature range of 0.2 GK $\ensuremath{\lesssim}T\ensuremath{\lesssim}$ 1.5 GK. The new rate is used to investigate its astrophysical impact via one-zone post-processing type-I x-ray burst calculations. It shows that the updated rate and new ${S}_{p}(^{58}\mathrm{Zn})$ value result in noticeable abundance variations for nuclei with $A=56$--59 and a reduction in $A=57$ abundance by up to $20.7%$, compared with the results using the recently published rate.

Nuclear mass measurements have recently been extended conspicuously to proton-rich region in the upper f p shell. The new data are utilized to study isospin symmetry breaking phenomena using Coulomb displacement energy (CDE) and triplet displacement energy (TDE) as probes. The new mass data, either measured for the first time or with greatly improved accuracy, removed several previously found anomalies in the systematical behavior in the f p shell. Remarkably, more regular odd-even staggering patterns can be established in both CDE and TDE, calling for a uniform explanation in terms of isospin-nonconserving (INC) forces across the sd, f7/2, and upper f p shells. By extending the large-scale shell-model calculation [Phys. Rev. Lett. 110, 172505 (2013)] to the upper f p-shell region, we found that, in order to describe the new data, the same INC force is required as previously used for the f7/2 shell. Especially, we propose the T = 1 TDE for those triplet nuclei, that have pp, nn, and pn pairs on top of a common even-even N = Z core, to be a good indicator for the isotensor component of isospin violating interactions, which is estimated here to be 150 keV.

Isochronous Mass Spectrometry is a practical approach for studying decays of short-lived isomers. However, solely relying on the time stamps between the isomer and ground state does not provide clear sign of decay. To address this issue, we proposed a method for extracting decay time point by analyzing the residuals of time stamps within a window of ( 20 mu s, , 180 mu s) ) after the start of data acquisition. Decay events out of the window were disregarded due to poor accuracy of revolution time. In this paper, we propose a novel approach based on the discrete Fourier transform technique, which was tested by simulation data. We found that the accuracy of the decay time point can be improved, leading to an expanded window of ( 15 mu s, , 185 mu s ). Furthermore, as the novel method was applied to experimental data, additional five decay events were identified. The newly determined half-life of 94mRu44+ m Ru 44+ is consistent with the previous value.

Neutron and gamma discrimination is a common issue in neutron detection. Cs 2 LiYCl 6 : Ce (CLYC) crystal, with its unique core-to-valence luminescence (CVL) mechanism for gamma rays, has excellent capability for neutron-gamma discrimination. This paper proposes a new preprocessing method called constant fraction alignment (CFA), based on the fast rise and slow decay characteristics of CLYC, to effectively improve discrimination performance. Unsupervised classification methods that do not require training data have a great advantage since pure neutron sources are difficult to obtain. As an unsupervised clustering method, Gaussian mixture model (GMM) is used to achieve neutron-gamma discrimination of data detected by CLYC, and the impact of different parameters on GMM results is studied. When the input dimension is high, GMM not only requires significantly more time but also reduces precision, so dimensionality reduction is necessary. Principal component analysis (PCA) is a commonly used dimensionality reduction method, and through analysis, it is found that using the first three components of PCA as inputs achieves the best performance. In the GMM solving process, selecting different covariance matrices based on data types can reduce running time while maintaining high accuracy. Diagonal mode is the most suitable according to comparison. Based on the same dataset, the accuracy of GMM is higher than that of charge comparison method and k-means++, with an accuracy of 99.96% for 252 Cf source and a false alarm rate as low as 0.01% for 137 Cs source.

Using a novel method of isochronous mass spectrometry, the masses of ^{62}Ge, ^{64}As, ^{66}Se, and ^{70}Kr are measured for the first time, and the masses of ^{58}Zn, ^{61}Ga, ^{63}Ge, ^{65}As, ^{67}Se, ^{71}Kr, and ^{75}Sr are redetermined with improved accuracy. The new masses allow us to derive residual proton-neutron interactions (δV_{pn}) in the N=Z nuclei, which are found to decrease (increase) with increasing mass A for even-even (odd-odd) nuclei beyond Z=28. This bifurcation of δV_{pn} cannot be reproduced by the available mass models, nor is it consistent with expectations of a pseudo-SU(4) symmetry restoration in the fp shell. We performed ab initio calculations with a chiral three-nucleon force (3NF) included, which indicate the enhancement of the T=1 pn pairing over the T=0 pn pairing in this mass region, leading to the opposite evolving trends of δV_{pn} in even-even and odd-odd nuclei.

A novel isochronous mass spectrometry, termed as Bρ -defined IMS, has been established at the experimental cooler-storage ring CSRe in Lanzhou. Its potential has been studied through high precision mass measurements of ^58 Ni projectile fragments. Two time-of-flight detectors were installed in one of the straight sections of CSRe, thus enabling simultaneous measurements of the velocity and the revolution time of each stored short-lived ion. This allows for calculating the magnetic rigidity Bρ and the orbit length C of each ion. The accurate Bρ (C) function has been constructed, which is a universal calibration curve used to deduce the masses of the stored nuclides. The sensitivity to single stored ions, fast measurement time, and background-free characteristics of the method are ideally suited to address nuclides with very short lifetimes and smallest production yields. In the limiting case of just a single particle, the achieved mass resolving power allows one to determine its mass-over-charge ratio m/q with a remarkable precision of merely ∼ 5 keV. Masses of T_z=-3/2 fp-shell nuclides are re-determined with high accuracy, and the validity of the isospin multiplet mass equation is tested up to the heaviest isospin quartet with A=55 . The new masses are also used to investigate the mirror symmetry of empirical residual proton-neutron interactions.

X-ray bursts are among the brightest stellar objects frequently observed in the sky by space-based telescopes. A type-I X-ray burst is understood as a violent thermonuclear explosion on the surface of a neutron star, accreting matter from a companion star in a binary system. The bursts are powered by a nuclear reaction sequence known as the rapid proton capture process (rp process), which involves hundreds of exotic neutron-deficient nuclides. At so-called waiting-point nuclides, the process stalls until a slower β + decay enables a bypass. One of the handful of rp process waiting-point nuclides is 64 Ge, which plays a decisive role in matter flow and therefore the produced X-ray flux. Here we report precision measurements of the masses of 63 Ge, 64,65 As and 66,67 Se—the relevant nuclear masses around the waiting-point 64 Ge—and use them as inputs for X-ray burst model calculations. We obtain the X-ray burst light curve to constrain the neutron-star compactness, and suggest that the distance to the X-ray burster GS 1826–24 needs to be increased by about 6.5% to match astronomical observations. The nucleosynthesis results affect the thermal structure of accreting neutron stars, which will subsequently modify the calculations of associated observables.

基于重离子储存环建立的等时性质谱术（IMS）是测量远离稳定线核素质量的有效工具。但是，采用常规IMS测量缺中子一侧的核素质量时，发现T z =-1/2和T z =-1核素的质量测量结果在宽时域范围内存在系统性偏差。本工作利用CSRe直线段上的双飞行时间（TOF）探测器，同时测量了循环离子的周期和速度。利用这些实验信息，对常规IMS质量测量中出现的系统性偏差进行了研究。发现系统偏差是由于储存的离子动量分布不对称以及储存环能量转变参数γ t 非恒定造成的。在离线数据处理时，发现通过限制动量接收度的大小，可以消除常规IMS质量测量中的系统偏差。这一结果对采用常规IMS进行质量测量具有重要参考价值和指导意义。