91176234
DESIGN AND FABRICATION OF A 5-CELL HIGH CURRENT SUPERCONDUCTING CAVITY
Superconducting Energy Recovery Linacs have various applications, such as hard X-ray, electron-ion colliders and electron cooler of ions. The key component for accelerating such high current beams is the superconducting radio frequency cavity. The design of a 1.3 GHz 5-cell high current superconducting cavity has been carried out under the cooperation between Peking University and Argonne National Laboratory. Radio frequency property and damping of the higher order modes of this cavity have been discussed and the final design is presented. Room temperature RF measurements are also described in the paper.
121908829
Amplitude and phase stability studies in a DC superconducting injector
The DC superconducting injector will be used in the PKU-THz facility which consists of a DC-gun and a 3+1/2-cell superconducting cavity. The cavity must accelerate the electron beam to 5.82 MeV which is susceptible to perturbations because of its narrow bandwidth. In this paper, the sources and influences of the perturbations in the 3+1/2-cell cavity are discussed. It is shown that the control system is essential for the cavity. The design of a feedback based digital RF low level control system for the 3+1/2-cell cavity is accomplished.
120411181
Recent progress in techniques utilized for particle accelerator
Particle accelerators are widely used in scientific research and industry. Recently, techniques utilized for accelerator are developed rapidly in China. We briefly review the recent progress in this field and primarily focus on superconducting RF, innovative structures for particle production and acceleration and beam diagnosis. Several advanced compact user facilities are also introduced.
117464950
Study on the multi-pass, multi-bunch beam breakup for 9-cell TESLA cavities in ERL *
Generally, Energy Recovery Linac (ERL) needs special designed high current superconducting RF cavities. In this paper, the threshold current of BBU for compact ERL facilities with 9-cell Tesla type cavities are investigated. The results show that it is feasible to adopt 9-cell Tesla cavity for compact ERL test facilities with just a few cavities and beam current around tens mA.
123774404
Stable Operation of the 2 K Cryogenic System for the Superconducting Accelerator at Peking University
A superconducting energy recovery linac test facility (PKU-SETF) was built at Peking University, and a 2K cryogenic system, which is the first closed-loop 2K cryogenic system for a superconducting accelerator in China, was constructed for the 1.3 GHz 3+1/2 cell dc-SRF injector. The main accelerator consists of two nine-cell TESLA-type superconducting cavities of the PKU-SETF The commissioning and stable operation of this 2 K cryogenic system was carried out. A helium pressure stability of better than ±0.1 mbar and a total refrigeration capacity of 65 W at a temperature of 2K was reached.
122621857
Cold RF test and associated mechanical features correlation of a TESLA-style 9-cell superconducting niobium cavity built in China
The RF performance of a 1.3 GHz 9-cell superconducting niobium cavity was evaluated at cryogenic temperatures following surface processing by using the standard ILC-style recipe. The cavity is a TESLA-style 9-cell superconducting niobium cavity, with complete end group components including a higher order mode coupler, built in China for practical applications. An accelerating gradient of 28.6 MV/m was achieved at an unloaded quality factor of 4 × 109. The morphological property of mechanical features on the RF surface of this cavity was characterized through optical inspection. Correlation between the observed mechanical features and the RF performance of the cavity is attempted.
56150758
DESIGN AND IMPLEMENTATION A SWITCHING MODE BIPOLAR POWER STAGE OF THE CORRECTION POWER SUPPLY
A bipolar power supply, which meets the internal specifications of originally correction power supplies, is designed to increase its efficiency. The power source of this power supply is designed that the working voltage mode on a dc bus is adjustable. Such voltage adjustment is conducted according to the state of current output and load. A new power switching device, which utilizes power MOSFET, giving much higher working frequency than former 60Hz, is used as an energy converting mode system of the switching power supply. This allows an increase of the correction power supply’s efficiency, and significant decrease of its weight. This new designed switching power supply provides a set of bipolar current sources, and following the working voltage, it can be automatically regulated with feedback by programmable setting. Conclusions and functional characteristics are as discussed in this paper.
111206305
STABILITY STUDY OF SUPERCONDUCTOR MAGNET POWER SUPPLIES AT TLS
In this paper, performance of three power supplies schemes driving the newly-developed Superconducting Wave Length Shifter Magnet at TLS is investigated. Due to the inherent structure of the Superconducting Magnet, the main and two accessory trimming power supplies are physically correlated with each others. Due to the inherent structure, in order to achieve high performance control of the magnet, slew rate control of the main power supply and the proper operation sequence have to be properly managed, otherwise, small current disturbance can occurs, which may degrade the stability of the performance of Superconducting Magnet.
210986666
TPS FAST CORRECTOR MAGNET POWER CONVERTER
M With the increasing demand of the current output accuracy on the TPS(Taiwan Photon Source) project, the MCOR 30 correction power supplies used in current TLS ring are no longer sufficient to meet the TPS requirement. Therefore, power supply group develops a high-precision low output current corrector magnet power supply with a DCCT as an output current feedback component for the future TPS ring. During the research and development experiment phase, we found the DCCT is more possible damaged than the other components. The implementation of the fast corrector magnet power converter is with keeping the architecture of the highprecision low output current power supply, but the DCCT output current feedback component is replaced with a current sensing Shunt resistor. This paper will discuss the design methods of utilizing several different types current sensing Shunt resistor to reduce the cost of power supply and the probability of damage, and improve frequency response of power supply.[1]
164614043
Analysis and Compensator Design of Magnet Correction Power Supply
POWER SUPPLY Yong-Seng Wong , Kuo-Bin Liu, Jhao-Cyuan Huang NSRRC, Hsinchu 30076, Taiwan . Abstract This paper presents a new method for the analysis and design of compensators for magnet correction (MC) power supply. The system has to need controllers to satisfy required gain and phase margin specifications and compensator by adding to circuit controller and switch. The gain-phase margin tester method can transform of the controller and find solutions on the figure. According to circuit frequency response and transfer function by theory analysis and simulation design new method compensators to improved anti-disturbance and stability of the system.
35578568
A safety protection device for bypass capacitor of the white circuit
This paper presents a new safety protection system for the bypass capacitor in the white circuit. In general, if the operation current of the white circuit deviates too much, the injection efficiency will be deteriorated and the white circuit bypass capacitor will be hurt. In order to detect the dynamic characteristics of the bypass capacitor to achieve protection function, the new protection system is proposed in this paper. The experimental results show that new protection system not only can monitor and detect the dynamic voltage and current of the bypass capacitor of the white circuit, but also prevent this bypass capacitor from being damaged.