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.
45531082
PIEZOELECTRIC TRANSFORMER BASED CONTINUOUS- CONDUCTION-MODE VOLTAGE SOURCE CHARGE-PUMP POWER FACTOR CORRECTION ELECTRONIC BALLAST *
This paper presents the piezoelectric transformer (PT) based continuous-conduction-mode (CCM) voltage source (VS) charge-pump (CP) power factor correction (PFC) electronic ballast. By replacing L-C resonant tank and transformer in the conventional CCM VS CP-PFC electronic ballast with PT, the cost and volume can be reduced. The experimental results show that the electronic ballast using PT achieve high power factor and the switches can be operated under zero-voltageswitching condition.
73696829
Increasing output current stability of power supply with component replacement
Quadrupole magnets of storage ring must be served with power supplies (quadrupole power supplies) with +/-100 ppm long-term output current stability in Synchrotron Radiation Research Center (SRRC). Using power supplies with lower long-term output current stability could save money but need another control loop to increase their performance that will increase the complexity of circuitry of quadrupole power supply. Without adding another control loop, some components of quadrupole power supply are replaced by ones with more precious and insensitive to temperature variation; so that the same circuitry structure of quadrupole power supply is kept without increasing its complexity and could reach +/-25 ppm long-term output current stability.
138669855
External Energy Dump for Superconducting Magnet of the Uni-polar Power System
15778530
Search for excited charmonium states in e+ e- annihilation at s**(1/2) = 10.6-GeV
We suggest searching for excited charmonium states in e + e - annihilation via double charmonium production at √s = 10.6 GeV with B factories, based on a more complete leading order calculation including both QCD and QED contributions for various processes. In particular, for the C = + states, the x c0 (nP) (n = 2, 3) and η c (mS) (m = 3, 4) may have appreciable potentials to be observed, while for the C = - states, the η c h c production and especially the X c1 h c production might provide opportunities for observing the h c with higher statistics in the future. A brief discussion for the X(3940) observed in the double charmonium production is included.
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.
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.
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.
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.