122993825
Field measurement of PEP-II LER dipoles and quadrupoles at IHEP
The field measurement of 209 dipoles and 320 quadrupoles for PEP-II LER will be finished at IHEP in June 1997. This paper covers the details of the magnetic measurement devices developed to measure these magnets as well as the results of the measurements.
121569083
MAKING SUPERCONDUCTING SOLENOID MAGNET
110035692
DESIGN OF LOW IMPEDANCE ELECTROSTATIC SEPARATORS FOR BEPC II
The multi bunch train collision is adopted in BEPC II. There are 4 horizontal electrostatic separators in the main ring to generate close-orbit displacement as "pretzels" which allow the electrons and positrons to be stored in the same vacuum chamber simultaneously without unwanted destructive collisions. In the separator the beam current (576mA) and the gap voltage (220 kV) are both very high. So there are five key problems that must be handled well: To reduce the beam impedance and loss factor; To absorb the high order modes (HOMs); To reduce the leakage of RF EM field; To extract the heats due to the HOMs losses and the SR power; To reduce the spark rate. Their analysis and the solutions are presented in this paper.
107782453
Reducing the Impedance of the Flange Gaps in BEPC Vacuum Chamber
39767157
Quiet start method in HGHG FEL simulation
Quiet start scheme is broadly utilized in self amplified spontaneous radiation (SASE) FEL simulations, which is proven to be correct and efficient. Nevertheless, due to the energy modulation and the dispersion section, the high gain harmonic generation (HGHG) FEL simulation will not be improved by the traditional quiet start method. A new approach is presented to largely decrease the number of macro-particles per slice that can be implemented in both time-independent and time-dependent simulation, accordingly expedites the high order harmonic cascade simulation and makes the multi-parameter scanning be possible.
115300891
ERHIC INTERACTION REGION DESIGN.
This paper presents the current interaction region design status of the ring-ring version of the electron-ion collider eRHIC (release 2.0).
56296740
RHIC performance for fy2012 heavy ion run
In the 2012 RHIC heavy ion run, we collided uraniumuranium (U-U) ions at 96.4 GeV/nucleon and copper-gold (Cu-Au) ions at 100 GeV/nucleon for the first time in RHIC. The new Electron-Beam Ion Source (EBIS) was used for the first time to provide ions for the RHIC physics program. After adding the horizontal cooling, 3-D stochastic cooling became operational in RHIC for the first time, which greatly enhanced the luminosity. With a double bunch merging technique in the Booster and AGS, the bunch intensities of Cu and Au ions in RHIC surpassed their projections. Both PHENIX and STAR detectors reached their integrated luminosity goals for both U-U and Cu-Au collisions. In this article we review the machine improvements and performances in this run.
123998905
RECIRCULATING ELECTRON LINACS (REL) FOR LHEC AND ERHIC
We present a design of a CW Electron Recovery Linacs (ERL) for future electron hadron colliders eRHIC and LHeC. In eRHIC, a six-pass ERL would be installed in the existing tunnel of the present Relativistic Heavy Ion Collider (RHIC). The 5-30 GeV polarized electrons will collide with RHIC's 50-250 GeV polarized protons or 20- 100 GeV/u heavy ions. In LHeC a 3-pass 60 GeV CW ERL will produce polarized electrons for collisions with 7 TeV protons. After collision, electron beam energy is recovered and electrons are dumped at low energy. Two superconducting linacs are located in the two straight sections in both ERLs. The multiple arcs are made of Flexible Momentum Compaction lattice (FMC) allowing adjustable momentum compaction for electrons with different energies. The multiple arcs, placed above each other, are matched to the two linac's straight sections with splitters and combiners.