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.
114890180
Improvement of Output Current Characteristics for Bira MCOR30 Correction Magnet Power Supply
The correction magnet power supplies installed at the Taiwan light source (TLS) are Bira Systems MCRO 30 power modules, a full-bridge configuration power stage converting the unregulated DC bulk power into a bi-polar current source. The MCOR 30 is theoretically regulated under a very fine control method, with this control method the Bira MCOR 30 should overcome the zero crossover distortion of a standard H-Bridge PWM schemes is used and result in a low frequency noise signature on the output when the magnet current is close to zero. The PWM control circuitry embedded in MCOR 30 theoretically but not really fulfills the purpose what the MCOR 30 want to achieve. With a home-made PWM control circuitry installed into MCOR 30, the width of real pulses can smoothly drop to zero, the MCOR 30 could output current not only with a low frequency noise signature but also with much higher bandwidth of frequency response and much lower Total Harmonic Distortion no matter what output current is demanded. INTRODUCTION The bipolar corrector magnet power supplies used in National synchronous radiation research center are BiRa systems MCOR 30 power modules[1]. The MCOR 30 is a modular product, designed to achieve high switching efficiency and small size, the maximum output about ± 50V / ± 30A, the output current with about 100Hz bandwidth should improve the overall speed of the electron beam orbit feedback system. The PWM control IC of MCOR 30 is a UC3856, in theory this PWM control IC is zero-crossing distortion, but in fact it is not, that results nonlinear behavior in low current output. In this paper, the IC LM555 presents a linear saw-tooth wave and combines an OP-AMP circuit to complete the fullbridge PWM control. The MCOR 30 could output current not only with a low frequency noise signature but also with much higher bandwidth of frequency response and much lower Total Harmonic Distortion no matter what output current is demanded. THE STRUCTURE OF CORRECTOR MAGNET POWER CONVERTER The MCOR 30 regulates the DC output current by controlling the pulse width modulation of an H-Bridge power MOSFET. This corrector magnet power converter could be roughly divided into four functional sections: Power regulation and filtering, Error amplifier, offset circuit, PWM control, Fault diagnosis, protection, monitoring and high precision current feedback system, as figure 1 shows. MCOR 30 is a full-bridge converter as figure 1 shows. The corrector power supply regulates the DC output current by controlling the pulse width of a half bridge power N-MOSFET array. For positive output current, Q1 and Q4 switch turn on and input DC source will charge energy and linear increase current to output load. When Q1 turn off the output current decay thought the Q4 and d3 turn on. For negative current is same to the mode [2].
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.
55862722
A KICKER PULSE POWER SUPPLY WITH LOW JITTER
The performance of kicker pulse power supplies is the main parameter to increase injection efficiency of storage ring that is an important issue for laboratory of synchrotron radiation research. The output current waveform of a kicker pulse power supply with low timing jitter is our goal for years that must satisfy the Top-Up mode injection requirement of NSRRC. In the past years kicker pulse power supplies of storage ring of NSRRC are immersed in isolation oil to sustain high voltage operational environment that led difficult to maintain, electronic component degrading and uneasy to tune parameters. Air-cooling and air-isolation is adopted in the new design structure for kicker pulse power supply system and an pre-trigger unit MA2709A is installed to trigger thyratron tube EEV1536A, a kicker pulse power supply with low timing jitter 1~2ns(p-p) is obtained and could satisfy for Top-Up mode injection and maintenance is more easier than before.
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]
122631725
The Study of Color Octet Matrix Elements Through $J/\psi$ and $\Upsilon$ Production in $e^{+}e^{-}$ Annihilation }
The next-to-leading radiative corrections and relativistic corrections to the inclusive heavy quarkonium production in $e^{+}e^{-}\rightarrow J/\psi+LH$ and $e^{+}e^{-}\rightarrow \Upsilon+LH$ are calculated within non-relativistic QCD frame. And the cross section with different the long distance matric elements has been given. We find that the inclusive heavy quarkonium production process in $e^{+}e^{-}$ annihilation can give a strong restrictions on the color octet matrix elements. And the long distance matric elements of P-wave channel for $J/\psi(\psi^\prime)$ would be very small. More measurement of $J/\psi(\psi^\prime)$ and $\Upsilon$ production associated with light hadron at BESIII, Belle, and BelleII can give more information about the color octet matrix elements.
118620211
Relativistic Correction to Color Octet J/psi Production at Hadron Colliders
The relativistic corrections to the color-octet $J/\psi$ hadroproduction at the Tevatron and LHC are calculated up to $\mathcal{O}(v^2)$ in nonrelativistic QCD factorization frame. The short distance coefficients are obtained by matching full QCD with NRQCD results for the partonic subprocess $g+g\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$, $q+\bar{q}\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$ and $g+q({\bar{q}})\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+q({\bar{q}})$. The short distance coefficient ratios of relativistic correction to leading order for color-octet states ${^1}S_{0}^{[8]}$, ${^3}S_{1}^{[8]}$, and ${^3}P_{J}^{[8]}$ at large $p_T$ are approximately -5/6, -11/6, and -31/30, respectively, for each subprocess, and it is 1/6 for color-singlet state ${^3}S_{1}^{[1]}$. If the higher order long distance matrix elements are estimated through velocity scaling rule with adopting $v^2=0.23$ and the lower order long distance matrix elements are fixed, the leading order cross sections of color-octet states are reduced by about a factor of $20\sim40%$ at large $p_T$ at both the Tevatron and the LHC. Comparing with QCD radiative corrections to color-octet states, relativistic correction is ignored along with $p_T$ increasing. Using long distance matrix elements extracted from the fit to $J/\psi$ production at the Tevatron, we can find the unpolarization cross sections of $J/\psi$ production at the LHC taking into account both QCD and relativistic corrections are changed by about $20\sim50%$ of that considering only QCD corrections. These results indicate that relativistic corrections may play an important role in $J/\psi$ production at the Tevatron and the LHC.
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.
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.
110104367
OPTICAL DESIGN OF THE ENERGY RECOVERY LINAC FEL AT PEKING UNIVERSITY
Peking University is currently designing an Energy Recovery Linac FEL (PKU-ERL-FEL). The system is consisted of a DC-SC photocathode injector, a superconducting linac which is composed of two nine cell TESLA-type cavities, an undulator and beam transport system. The objectives of the PKU-ERL-FEL are providing infrared FEL and building a test-bed for the study of beam dynamics and accelerator technology for energy recovery. In this paper the main parameters of the PKU-ERL-FEL are described and the optical design for the beam transport of PKU-ERL-FEL is presented. The simulation is carried out using the typical particle tracking codes such as elegant.