arXiv subjects

Jian-Cheng Yang

Publications and source records attributed to Jian-Cheng Yang.

10 recordsLinked to original sources

arXiv2025

Beam-commissioning-oriented optics study of HFRS Phase-I based on measured magnetic field data

The construction of the first phase of the High energy FRagment Separator (HFRS Phase-I) has already been completed and it is anticipated to start beam commissioning in autumn 2025. This paper presents the first order and higher order beam optics calculations for the HFRS Phase-I, using measured magnet data, and evaluates its experimental performance in preparation for beam commissioning. The first order optics of HFRS is calculated based on the sliced magnetic fields and the higher order aberrations are corrected using a self-compiled program. Monte Carlo particle tracking is employed to analyze the beam phase spaces on the focal planes. The experimental performance of the machine is evaluated through Monte Carlo simulations. The beam phase spaces on the focal planes are thoroughly examined, demonstrating that the higher order aberrations have been well corrected. Moreover, the experimental performance of HFRS is evaluated based on the corrected higher order optics, yielding satisfactory results: the secondary beams of interest can be well separated and exhibit high transmission efficiency. This work provides valuable insights for the upcoming beam commissioning of HFRS Phase-I. The effective correction of higher order aberrations and optimized magnet settings lay a solid foundation for future experiments.

physics.acc-ph↗

arXiv2025

A further study on the high-precision optics for HIAF-BRing

The High Intensity heavy ion Accelerator Facility (HIAF) successfully accelerated the 18O6+ beam on October 27, 2025. This paper presents a further simulation study on the high-precision optics, namely sliced optics, of the Booster Ring (BRing) at HIAF based on measured magnetic fields, focusing on three aspects: (1) closed-orbit distortion (COD) and variations in optical parameters induced by errors; (2) closed-orbit correction; (3) dynamic aperture. Specifically, detailed investigations are conducted on COD and optical parameter variations caused by magnet alignment errors and dipole magnet field errors, alongside simulations of closed-orbit correction and detailed calculations of BRing's dynamic aperture. Results show the sliced optics outperforms the original optics in COD control. Without chromaticity correction, its dynamic aperture is superior to the original; after chromaticity correction, it remains comparable. This study provides valuable insights for accelerator tuning and optimization.

physics.acc-ph↗

arXiv2025

High-precision Beam Optics Calculation of the HIAF-BRing Using Measured Fields

The construction of the High Intensity heavy ion Accelerator Facility (HIAF) has been completed, with current efforts focused on subsystem commissioning. Beam commissioning is scheduled for autumn 2025, marking a critical milestone in the HIAF project. This paper presents high-precision optics calculations for the Booster Ring (BRing) of HIAF, a key component for achieving stable heavy-ion beam acceleration. Leveraging high-precision magnetic field data, each magnet is divided into hundreds of slices, thus establishing a high-precision sliced optics model for BRing. Detailed calculations of BRing's optics are presented in this work. Critical parameters including tunes and betatron functions of the lattice based on the measured magnetic fields and those of the ideal lattice have been compared. The results highlight the impact of realistic magnetic field on beam dynamics and provide essential insights for accelerator tuning and optimization. These findings serve as a fundamental reference for beam commissioning and long-term operation, ensuring beam stability and performance reproducibility in HIAF.

physics.acc-ph↗

arXiv2021

Charge resolution in the isochronous mass spectrometry and the mass of $^{51}$Co

Isochronous mass spectrometry (IMS) of heavyion storage rings is a powerful tool for the mass measurements of short-lived nuclei. In IMS experiments, masses are determined through precision measurements of the revolution times of the ions stored in the ring. However, the revolution times cannot be resolved for particles with nearly the same mass-to-charge (m/q) ratios. To overcome this limitation and to extract the accurate revolution times for such pairs of ion species with very close m/q ratios, in our early work on particle identification, we analyzed the amplitudes of the timing signals from the detector based on the emission of secondary electrons. Here, the previous data analysis method is further improved by considering the signal amplitudes, detection efficiencies, and number of stored ions in the ring. A sensitive Z-dependent parameter is introduced in the data analysis, leading to a better resolution of $^{34}$Ar$^{18+}$ and $^{51}$Co$^{27+}$ with A/Z=17/9. The mean revolution times of $^{34}$Ar$^{18+}$ and $^{51}$Co$^{27+}$ are deduced, although their time difference is merely 1.8 ps. The uncorrected, overlapped peak of these ions has a full width at half maximum of 7.7 ps. The mass excess of $^{51}$Co was determined to be -27332(41) keV, which is in agreement with the previous value of -27342(48) keV.

nucl-ex↗

arXiv2018

Low energy range dielectronic recombination of Fluorine-like Fe17+ at the CSRm

The accuracy of dielectronic recombination (DR) data for astrophysics related ions plays a key role in astrophysical plasma modeling. The measurement of the absolute DR rate coefficient of Fe17+ ions was performed at the main cooler storage ring at Institute of Modern Physics, Lanzhou, China. The experimental electron-ion collision energy range covers first Rydberg series up to n = 24 for the DR resonances associated with the 2P1/2--2P3/2 dn = 0 core excitations. A theoretical calculation was performed by using FAC code and compared with the measured DR rate coefficient. Overall reasonable agreement was found between the experimental results and calculations. Moreover, plasma rate coefficient was deduced from the experimental DR rate coefficient and compared with the available results from the literature. At the low energy range significant discrepancies were found therein and the measured resonances challenged state-of-the-art theory at the low collision energies.

physics.atom-ph↗

arXiv2018

Towards the full realization of the RIBLL2 beam line at the HIRFL-CSR complex

The RIBLL2 in-flight separator at IMP, the secondary beam line between two storage rings at the \blue{\uwave{Heavy Ion Research Facility in Lanzhou (HIRFL-CSR)}}, has been commissioned to study the rare-isotope beam (RIB) physics at around 300 MeV/nucleon for the first time, in combination of the external target facility (ETF). The unambiguous particle identification in mass and charge states for $^{18}$O and $^{40}$Ar fragments has been achieved in recent experiments. A full realization of RIBLL2 will open many potentials to address important RIB physics problems at around 300 MeV/nucleon.

physics.acc-ph↗

arXiv2017

Simulation of longitudinal dynamics of laser-cooled and RF-bunched C$^{3+}$ ion beams at heavy ion storage ring CSRe

Laser cooling of relativistic heavy ion beams of Li-like C$^{3+}$ and O$^{4+}$ is being in preparation at the experimental Cooler Storage Ring (CSRe). Recently, a preparatory experiment to test important prerequisites for laser cooling of relativistic $^{12}$C$^{3+}$ ion beams using a pulsed laser system has been performed at the CSRe. Unfortunately, the interaction between the ions and the pulsed laser cannot be detected. In order to study the laser cooling process and find the optimized parameters for future laser cooling experiment, a multi-particle tracking method was developed to simulate the detailed longitudinal dynamics of laser-cooled ion beams at the CSRe. The simulations of laser cooling of the $^{12}$C$^{3+}$ ion beams by scanning the frequency of RF-buncher or continuous wave (CW) laser wavelength were performed. The simulation results indicated that a large momentum spread ion beams could be laser-cooled by the combination of only one CW laser and the RF-buncher and shown the requirements of a successful laser cooling experiment. The optimized parameters for scanning the RF-buncher frequency or laser frequency were obtained. Furthermore, the heating effects were estimated for laser cooling at the CSRe. The Schottky noise spectra of longitudinally modulated and laser-cooled ion beams was simulated to fully explain and anticipate the experimental results. The combination of Schottky spectra from the highly sensitive resonant Schottky pick-up and the simulation methods developed in this paper will be helpful to investigate the longitudinal dynamics of RF-bunched and ultra-cold ion beams in the upcoming laser cooling experiments at the CSRe.

physics.acc-ph↗

arXiv2016

Injection method of barrier bucket supported by off-aligned electron cooling for CRing of HIAF

A new accelerator complex, HIAF (the High Intensity Heavy Ion Accelerator Facility), has been approved in China. It is designed to provide intense primary and radioactive ion beams for research in high energy density physics, nuclear physics, atomic physics as well as other applications. In order to achieve a high intensity of up to 5e11 ppp 238U34+, the Compression Ring (CRing) needs to stack more than 5 bunches transferred from the Booster Ring (BRing). However, the normal bucket to bucket injection scheme can only achieve an intensity gain of 2, so an injection method, fixed barrier bucket (BB) supported by electron cooling, is proposed. To suppress the severe space charge effect during the stacking process, off-alignment is adopted in the cooler to control the transverse emittance. In this paper, simulation and optimization with the BETACOOL program are presented.

physics.acc-ph↗

arXiv2015

Closed orbit correction of HIMM synchrotron

The correction of closed orbit has great influence on the operation of synchrotron. The design of correction system is one significant component of lattice design. It is suggested to set BPMs at the peaks of betatron oscillation. The correctors need to be located at the positions where \b{eta} function is large or the sources of large errors. In the simulation of the closed orbit correction of HIMM synchrotron, one important reason affecting the result of horizontal correction is the longitudinal alignment error of dipole magnet. It is advisable to decrease this kind of alignment error while the deflection angle of dipole magnet is large.

physics.acc-ph↗

arXiv2015

Simulation of proton radiography terminal at IMP

Proton radiography is used for advanced hydrotesting as a new type radiography technology due to its powerful penetration capability and high detection efficiency. A new proton radiography terminal will be developed to radiograph static samples at Institute of Modern Physics of Chinese Academy of Science (IMP-CAS). The proton beam with the maximum energy of 2.6 GeV will be produced by Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring (HIRFL-CSR). The proton radiography terminal consists of the matching magnetic lens and the Zumbro lens system. In this paper, the design scheme and all optic parameters of this beam terminal for 2.6GeV proton energy are presented by simulating the beam optics using WINAGILE code. My-BOC code is used to test the particle tracking of proton radiography beam line. Geant4 code and G4beamline code are used for simulating the proton radiography system. The results show that the transmission efficiency of proton without target is 100%, and the effect of secondary particles can be neglected. In order to test this proton radiography system, the proton images for an aluminum plate sample with two rectangular orifices and a step brass plate sample are respectively simulated using Geant4 code. The results show that the best spatial resolution is about 36μm, and the differences of the thickness is not greater than 10%.

physics.acc-ph↗