108791635
Simulation of kicker pulser with MATLAB simulink
The pulser system of kicker magnet in Synchrotron Radiation Research Center (SRRC) is a 25 kV in-house-designed high voltage system which generates a pulse current to steer the injected beam from booster ring into storage ring. The injection efficiency is strongly influenced by the performance of this pulser. It is very difficult and dangerous to measure and modify the circuit inside of pulser because of high voltage environment. Before any performance improvement, simulation of circuitry of this pulser with MATLAB Simulink is a safe way to understand the behavior of every component. Model of such system will be demonstrated and modification of such system will become easier for future applications.
55337938
DESIGN AND MODELING OF THE STEP DOWN PIEZO TRANSFORMER
The energy conversion and the step down voltage waveform of the piezo transformer are required to achieve optimal working condition of the resonant frequency. To meet this requirement, a reliable and precise instrument is needed to scan the resonant point of the piezo transformer such that its output power performance can meet the required specification. In this paper, the design and model of a new step down piezo transformer deployed in NSRRC is described. This step down piezo transformer is capable of delivering energy conversion with high efficiency performance, which is better than traditional transformer, and the voltage transfer ratio is correct. Using the simulation circuit model to develop driver circuit of it is also included in the design of this new step down transformer. It has been tested and proven to be working well in power conversion with excellent efficiency and reliability.
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]
55506316
The Design and Fabrication of the Kicker Power Supply for TPS Project
The preliminary test results of the kicker power supply for TPS (Taiwan Photon Source) project will be presented in this report. The achieved capability of this test unit demonstrates that it fulfills the design requirement of providing half-sine pulsed current of 2.5 kA (peak), 5.2 μs (base-width), with jitter < 1 ns (peak-to-peak). Both units of using thyratron and IGBT switches are built with the same requirements. The technical considerations of both units for this particular application will be discussed. INTRODUCTION The Taiwan Photon Source (TPS) under construction consists of a 150 MeV electron linac, a 3 GeV full energy booster, and a 3 GeV storage ring. The storage ring is planned to operate top-up at 400 mA. The top-up filling process will take place periodically within about every 100 seconds. In order to fulfill this requirement, the injection kickers will be triggered repeatedly at the same repetition rate. This proposed topup operation mode requires stringent performance of the 4 injection kickers for good stability on pulse amplitude and jitter, and in particular, pulse-shape matching among these 4 kickers. Test units of the kicker pulser have been built to examine their feasibility. Pulsers using both thyratron and IGBT switches have been tested. The results show that both units fulfill the pulser requirements on amplitude and jitter stability. The system configuration and the test results are briefly described in this report. PERFORMANCE REQUIREMENTS The circumference of the TPS storage ring is 518.4 m [1]. Beam injection will be taken place at a 10 m long straight section. The proposed injection scheme demand a 5.2 μs (base-width) half-sine pulse for the injection kickers in order to perform four-turn injection process [2]. The estimated parameters had been applied to examine and evaluate the feasibility of building pulse power supply for kicker in house. The design of the prototype kicker magnet requires the driving peak current to be 2.5 kA. The suggested stability goals of both pulse amplitude and jitter for the test unit are given as 0.5% and 2 ns, respectively. Since top-up mode will be implemented in the future for routine user operation, performance on high reliability and small long term drift of the test unit are required. The stability will be examined and analyzed for this purpose. The estimated parameters for evaluating kicker pulser test unit are given in Table 1. Table 1: Parameters for evaluating kicker pulser test unit straight section (m) 10 magnet length (m) 0.6
73583477
TPS DIGITAL CORRECTOR MAGNET POWER CONVERTER BASED ON FPGA
This paper is to realize digital corrector magnet power supply based on FPGA. The purpose of the study is to implement digital PID controller by using Xilinx programmable gate array (FPGA), in hope of enhancing output performance and reducing circuit size. The ±10A/± 48V output corrector magnet digital FPGA power converter uses a full bridge configuration, the switching frequency of power MOSFET is 40 kHz, in which each bridge leg has its own independent PWM controller and the output current bandwidth is 1kHz when connected with the corrector magnet load. Using a DCCT as the current feedback component, the output current ripple of this converter could be lower than 10ppm. In this paper, the hardware structure and control method of the corrector magnet power converter will be described and the test results will be demonstrated.
73599484
High efficiency linear power supply with a preregulator controlled by keeping constant R/sub DS/ of MOSFET
In Synchrotron Radiation Research Center (SRRC) more than ninety linear power supplies with 100 ppm long-term stability are served for correction magnets. To increase the well-known efficiency problem of linear power supply, inside a customer-made bipolar linear power supply a homemade pre-regulator circuitry is in series in front of power stage. By using constant V/sub DS/ controlled pre-regulator, the power consumption of linear power supply itself could be reduced and the efficiency changes with respect to the output power. On the other hand, with constant R/sub DS/ controlled pre-regulator, the efficiency is even higher and is the ratio of load resistance and R/sub DS/. Design and performance of the pre-regulator circuitry are demonstrated.
17109568
Inclusive charmonium production via double $c \bar{c}$ in $e^{+} e^{-}$ annihilation
Motivated by the recent observation of double charm quark pair production by the Belle Collaboration, we calculate the complete ${\cal O}(\alpha_{s}^{2})$ inclusive production cross sections for $\eta_{c}$, $J/\psi$, and $\chi_{cJ}$(J=0, 1, 2) plus $c\bar{c}$ in $e^+ e^-$ annihilation through a virtual photon. We consider both color-singlet and color-octet contributions, and give the analytical expressions for these cross sections. The complete color-singlet calculations are compared with the approximate fragmentation calculations as functions of the center-of-mass energy $\sqrt{s}$. We find that most of the fragmentation results substantially overestimate the cross sections (e.g. by a factor of $\sim$4 for $\chi_{c1}$ and $\chi_{c2}$) at the Belle and BaBar energy $\sqrt{s}=10.6$GeV. The fragmentation results become a good approximation only when $\sqrt{s}$ is higher than about 100GeV. We further calculate the color-octet contributions to these cross sections with analytical expressions. We find that while the color-octet contribution to $J/\psi$ inclusive production via double charm is negligible (only about 3%), the color-octet contributions to $\chi_{c1}$ and $\chi_{c2}$ can be significant.
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.
117409239
$J / \psi$ electromagnetic production associated with light hadrons at $B$ factories
The electromagnetic productions of $J \psi$ associated with light hadrons(LH) and leptonic pairs($\mu^+\mu^-$, $\tau^+\tau^-$) at $B$ factories are studied. We find that the direct electromagnetic production cross sections of $J / \psi$($\psi(2S)$) associated with light hadrons is about $0.10(0.04)$ pb. The direct production cross sections of $J / \psi$($\psi(2S)$) associated with $\mu^+\mu^-$ is about $0.056(0.020)$ pb. If we include the contributions from $\psi(2S)$ decay, we can get the prompt cross section $\sigma[e^+e^- \to J/\psi +\mu^+\mu^-]=(0.068 \pm 0.002)$ pb, about $(16 \pm 5) %$ of the Belle data $\sigma[e^+e^- \to J/\psi +X_{non-c\bar c}]=(0.43\pm 0.09\pm 0.09)$ pb, meanwhile the $e^+e^- \to J/\psi +\tau^+\tau^-$ process only contributes $2 %$. The prompt cross section $\sigma[e^+e^- \to J/\psi +Light Hadrons]=(0.121 \pm 0.005)$ pb is about $(28 \pm 8) %$ of the Belle data.
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.
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.