The construction and commissioning of HIRFL-CSR were finished in 2007. From 2000 to 2005 the subsystem and key devices of CSR were successfully fabricated, such as magnet, power supply, UHV system, e-cooler, electric-static deflector with the septum of 0.1 mm, and the fast-pulse kicker with the rise time of 150 ns. After that the CSR commissioning activities were performed in 2006 and 2007, including the accumulation of those heavy ions of C, Ar, Kr and Xe by the combination of stripping injection (STI) or multiple multi-turn injection (MMI) and e-cooling with a hollow e-beam, wide energy-range synchrotron ramping by changing the RF harmonic-number at mid-energy, the beam stacking in the experimental ring CSRe, the RIBs mass-measurement with the isochronous-mode in CSRe by using the time-of-flight method, and the ion beam slow-extraction from CSRm.
A new SSC (Separated Sector Cyclotron)-Linac is being designed to serve as an injector for the SSC at the HIRFL (Heavy Ion Research Facility Lanzhou). The beam intensity at the LEBT (Low Energy Beam Transport) for the heavy ions after the selection is typically low and the space charge effects are inconspicuous. The space charge effects become obvious when the beam current increases to a few hundred microamperes. The emittance growth deriving from the space charge effects may be particularly troublesome for the following linac and cyclotron. An optical system containing three solenoids has been designed for the LEBT to limit the beam emittance and to avoid the unnecessary beam loss in the cyclotron, as well as for the purpose of immunizing the LEBT emittance growth due to the space charge effects. The results of the PIC (ParticleIn-Cell) mode simulation illustrate that this channel could limit the beam emittance growth and increase the beam brightness.
A linear accelerator as a new injector for the SSC(Separated Sector Cyclotron) of the HIRFL(Heavy Ion Research Facility Lanzhou) is being designed.The DTL(Drift-Tube-Linac) has been designed to accelerate 238U34+ from 0.140 MeV/u to 0.97 MeV/u.To the first accelerating tank which accelerates 238U34+ to 0.54 MeV/u,the approach of Alternating-Phase-Focusing(APF) is applied.The phase array is obtained by coupling optimization software Dakota and beam optics code LINREV.With the hybrid of Multiobjective Genetic Algorithm(MOGA) and a pattern search method,an optimum array of asynchronous phases is determined.The final growth,both transversely and longitudinally,can meet the design requirements.In this paper,the deign optimization of the APF DTL is presented.
A Penning trap system called Lanzhou Penning Trap(LPT) is now being developed for precise mass measurements at the Institute of Modern Physics(IMP).One of the key components is a 7 T actively shielded superconducting magnet with a clear warm bore of 156 mm.The required field homogeneity is 3 × 10-7 over two 1 cubic centimeter volumes lying 220 mm apart along the magnet axis.We introduce a two-step method which combines linear programming and a nonlinear optimization algorithm for designing the multi-section superconducting magnet.This method is fast and flexible for handling arbitrary shaped homogeneous volumes and coils.With the help of this method an optimal design for the LPT superconducting magnet has been obtained.
A new linear accelerator system,called the SSC-Linac injector,is being designed at HIRFL (the heavy ion research facility of Lanzhou).As part of the SSC-Linac,the medium energy beam transport (MEBT) consists of seven magnetic quadrupoles,a re-buncher and a diagnose box.The total length of this segment is about 1.75 m.The beam dynamics simulation in MEBT has been studied using the TRACK 3D particle-in-cell code,and the simulation result shows that the beam accelerated from the radio frequency quadrupole (RFQ) matches well with the acceptance of the following drift tube linac (DTL) in both the transverse and longitudinal phase spaces,and that most of the particles can be captured by the final sector focusing cyclotron for further acceleration.The longitudinal emittance of the RFQ and the longitudinal acceptance of the DTL was calculated in detail,and a multi-particle beam dynamics simulation from the ion source to the end of the DTL was done to verify the original design.
SSC-Linac[1] as the injector for the Separated Sector Cyclotron (SSC), is being constructed at national labo-ratory Heavy Ion Research Facility at Lanzhou (HIRFL). The injection and extraction energy are 3.7 keV/u and1.025 MeV/u, respectively. Fig. 1 shows the front end section of the SSC-Linac. The high charges state continuswave (CW) 4-rod RFQ has been designed and fabricated for some years. From the end of 2013, the commissioningof the RFQ was performed and the beam test was carried out in April 2014. In this paper the experiment resultwill be presented.
