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Y.C. Liu,
H.P. Chang,
J. Chen,
P.J. Chou,
K.T. Hsu,
K.H. Hu,
Changhor Kuo,
C.C. Kuo,
K.K. Lin,
M.H. Wang,
G.H. Luo
[show abstract]
[hide abstract]
ABSTRACT: The Taiwan light source began top-up operation in October 2005 with an initial beam current of 200 mA. This was subsequently raised to 300 mA. In the early phase of top-up operation, the injection efficiency varied markably under different machine operating conditions. A procedure to optimize and maintain the injection efficiency is presented. Future improvements and the prospects for a 400 mA top-up operation are discussed.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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T.T. Yang,
K.T. Hsu,
S.Y. Hsu,
K.B. Liu,
C.S. Fann, Y.C. Liu,
H.M. Shih,
M.S. Yeh,
W.K. Lau,
A.P. Lee,
C.C. Liang,
J. Hwang,
K.K. Lin
[show abstract]
[hide abstract]
ABSTRACT: A single cell rf-gun cavity is designed and fabricated for the purpose of examining the feasibility of installing a thermionic rf-gun at NSRRC instead of a photocathode rf- gun considered previously. The operating frequency of the rf-gun cavity is set at 2856 MHz in order to utilize the available XK-5 klystron and linac. The fabricated parts of the OFHC copper cavity are brazed together in-house and then the cavity is characterized by rf measurement. It shows that the cavity gives very good character in terms of high quality factor, relaxed tuning range, adequate coupling coefficient, and reasonable reproducibility. The properties of the cavity are further explored by measuring the field profile and its response to an rf pulse in which the filling time is deduced. The measurement results of this brazed cavity are described and summarized in this report.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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G. H. Luo,
H. P. Chang,
J. C. Chang,
C. T. Chen,
Jenny Chen,
J. R. Chen,
C. S. Fann,
K. T. Hsu,
C. S. Hwang,
C. C. Kuo,
K. B. Liu, Y. C. Liu,
R. J. Sheu,
T. S. Ueng,
D. J. Wang,
M. H. Wang
[show abstract]
[hide abstract]
ABSTRACT: During the last two years, a series of beam parameters measurement,
subsystem checkout, installation of various sensors, control program
modification and hardware upgrade made the top-up injection possible in
practical routine operation. Top-up injection is an operation mode in
which the beam current in the storage ring is maintained above certain
level by frequent injections. The routine current stability is in the
range of 10-3 for long period of operation. The Top-up injection
provides advantages in operation such as lower emittance, higher
current, smaller coupling, smaller ID gaps, exotic bunch filling
patterns, and higher bunch charge. It also provides constant thermal
loading on all components in the storage ring and the optics components
of beamlines, as well as constant signal to the beam position monitor.
Discussions on the results of some measurements of booster and storage
ring, the requirement of hardware upgrade and the summary of routine
Top-up operation will be presented in this paper.
12/2006; 879:13-16.
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[show abstract]
[hide abstract]
ABSTRACT: Nonlinear beam dynamics experiments were conducted at the Taiwan
Light Source (TLS) of the Synchrotron Radiation Research Center (SRRC).
We employed a turn-by-turn BPM system to obtain nonlinear dynamics of
the excited bunched beam. Extracted nonlinear parameters are compared
with the simulation results
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001; 02/2001
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[show abstract]
[hide abstract]
ABSTRACT: The storage ring at SRRC is highly promising as an ultraviolet to
soft X-ray radiation source for use in basic research and industrial
applications. Energy ramping of the storage ring can push the critical
photon energy to the edge of hard X-ray. The tune drifting, during the
ramping procedure, is expected and should be minimized such that the
beam can survive through the ramping process. The betatron frequencies
and the ramping function of magnets were carefully monitored in order to
avoid the betatron tunes crossing the fatal resonance line. A successful
ramping results and lattice parameters were measured and discussed in
this paper. The measured photon flux increased by six to seven folds at
the X-ray beam line. Life time reaches 9 hours of 200 mA beam current
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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[show abstract]
[hide abstract]
ABSTRACT: A new approach to measure and locate beam losses in the SRRC
storage ring (Taiwan Light Source, TLS) by using a semiconductor beam
loss monitor (BLM) is presented in this report. Small size and low unit
cost make it possible to be placed around the machine for amount of 50
in 120 meters storage ring. Beam loss counts are collected by
multi-channel scalers on VME crates and are updated to databases on
workstations dynamically
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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[show abstract]
[hide abstract]
ABSTRACT: The Taiwan Light Source (TLS) is a synchrotron radiation facility
that has operated for the past four years at SRRC. At this time, the
operating energy has been increased from 1.3 GeV to 1.5 GeV, and the
beam lifetime is 9 hours at a current of 200 mA. The monthly uptime is
normally more than 90%, and the orbit stability better than 5
micrometers. Both transverse and longitudinal instabilities have been
observed, and the corresponding feedback systems have been constructed.
The transverse feedback system is in routine operation. A fast orbit
feedback system is capable of restricting orbit errors to within 10
micrometers, even in the presence of strong orbit perturbations such as
insertion-device gap changes
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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[show abstract]
[hide abstract]
ABSTRACT: Photon stimulated desorption from aluminum surfaces was studied by irradiating an aluminum chamber in the 1.3 GeV electron storage ring at the Synchrotron Radiation Research Center. Experiments on aluminum samples were also performed in an experimental station. The behavior of water vapor, the main concern in this work, was quite different from that of the other gases. A time delay between the peak of the H <sub> 2 </sub> O signal and the starting time of irradiation was observed. Effects due to different conditions such as beam current, pumping speed, and beam dose of the storage ring were investigated. © 1997 American Vacuum Society.
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 06/1997; · 1.25 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The operation of the Synchrotron Radiation Research Center 1.3 GeV synchrotron light source vacuum system shows good features of quick beam self‐cleaning, low carbonaceous gas desorption, and less dust. The phenomenon of the photon induced desorption (PID) has been studied. Recently, a set of new vacuum chambers for wiggler were installed, and the commissioning of the storage ring was restarted. The pressure rise and the PID coefficients during the beam running both in the straight and bending chambers were compared. The performance of the overall vacuum system is to be described. © 1996 American Vacuum Society
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 12/1996; · 1.25 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: An aluminum vacuum chamber 3 m long and 21.5 mm high was fabricated, tested and installed in the wiggler section of the Taiwan Light Source at the Synchrotron Radiation Research Center. The chamber was made by the extrusion method and machined to a flatness of ≪±0.1 mm/3 m. The inner aperture included an elliptical channel (17 mm×80 mm) for electron beam and a pumping channel for a nonevaporable getter (NEG) strip. Two heat‐treated Be–Cu springs were used to absorb the thermal expansion of the NEG strip during activation. After installation of the wiggler chamber in the storage ring, a pressure of 0.45 nTorr was reached after an in situ bakeout with NEG activated. The high temperature properties of the Be–Cu spring and the vacuum performance of the complete chamber have been tested. No obvious influence, due to the narrow beam aperture or limited gas conductance to the beam life time was found. © 1996 American Vacuum Society
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 08/1996; · 1.25 Impact Factor
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C.C. Kuo,
K.T. Hsu,
G.H. Luo,
W.K. Lau,
C. Wang,
H.P. Chang,
L.H. Chang,
M.H. Wnag,
J.C. Lee,
C.S. Hsue,
W.T. Weng, Y.C. Liu
[show abstract]
[hide abstract]
ABSTRACT: A 1.3 GeV synchrotron radiation storage ring at SRRC has been
operated for more than a year since October 1993. Starting from April
1994, the machine has been open to the user community. In February 1995,
we installed a wiggler magnet of 1.8 tesla 25-pole in the ring and
successfully commissioned. The machine was scheduled for the users' runs
from the middle of April this year. We describe the performance of the
machine without the wiggler magnet system and then report the wiggler
effects on the beam dynamics of the storage ring, e.g., tune shift,
beta-beating, orbit change, nonlinear dynamics effect, etc. Some
measurements are compared with the model prediction and agreement
between them was fairly good. Possible actions to minimize wiggler
effects have been taken, such as orbit correction as a function wiggler
gap change. The machine improvement projects, such as longitudinal and
transverse damping systems as well as an orbit stability feedback system
are under construction and will be in use soon
Particle Accelerator Conference, 1995., Proceedings of the 1995; 06/1995
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[show abstract]
[hide abstract]
ABSTRACT: The 1.3 GeV storage ring at SRRC will provide an ultra-violet to
soft X-ray radiation source to the potential users. The energy ramping
of storage ring will push the critical photon energy to the edge of hard
X-ray. There are several ways to ramp the electron energy, for example,
increasing the extraction energy to 1.5 GeV from booster directly,
ramping the magnets' power supplies with synchronized function
generators, or asynchronized ramping of magnets at storage ring, etc.
The tune drifting during the ramping procedure is expected and should be
minimized such that the beam can survive through the ramping process.
The betatron frequencies and ramping function of magnets were carefully
monitored in order to avoid the betatron tunes cross the resonance line.
A successful asynchronized ramping result will be presented in this
paper
Particle Accelerator Conference, 1995., Proceedings of the 1995; 06/1995
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W.T. Weng,
H.P. Chang,
J.R. Chen,
Y. Cheng,
K.T. Hsu,
C.C. Kuo,
L.C. Lee,
K.K. Lin, Y.C. Liu,
G.H. Luo,
K.L. Tsang,
S.Y. Fu,
I. Hsu,
C.S. Hsue,
J.S. Leu
[show abstract]
[hide abstract]
ABSTRACT: To satisfy the need of users of the synchrotron radiation at SRRC,
the photon flux at the end station has to be kept at a constant with
minimum fluctuation. The sources of flux variation attributable to the
electron beam in the storage ring have been carefully studied and the
effects on the flux have been investigated. The sources include floor
vibration, power supply ripples, cooling water, ion trapping and
transverse instability. The cures attempted or in plan include removal
of vibration sources, reduction of ripple, local orbit feedback, ion
cleaning and damping. A special diagnostic beamline has been constructed
and used solely for accelerator studies and improvements
Particle Accelerator Conference, 1995., Proceedings of the 1995; 06/1995
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[show abstract]
[hide abstract]
ABSTRACT: Glow discharge cleaning treatments on aluminum surfaces were studied by the secondary ion mass spectroscopy method. The cleaning effects of direct current and radio frequency glow discharges with H 2 and Ar gases were compared. The elements or compounds of the contamination or reaction depositions were identified from analyses of the mass spectra and energy distribution of the secondary ions. Base material, chemical solvents, sputtered depositions, hydrogen –oxygen–hydroxyls, and hydrocarbons were the five major sources of the secondary ions. The energy distribution curves were similar for secondary ions with similar compound complexity, and the cleaning effects were nearly identical for secondary ions with the same type of origin. © 1995 American Vacuum Society
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 06/1995; · 1.25 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The installation of the vacuum system of the Synchrotron Radiation Research Center 1.3 GeV electron storage ring was completed in January 1993. Both the straight (S‐) chambers and bending (B‐) chambers are made of aluminum alloy. Oil‐less machining processes were adopted in the fabrication of the B‐chambers and some components of the S‐chambers. Stringent welding processes were performed in a clean room in order to get a good welding quality and a clean chamber surface. The pumping system is a combination of several kinds of oil‐free pumps. In the commissioning phase, the photon induced desorption phenomenon was clearly observed. The major desorbed gases are H 2 , CH 4 , CO, and CO 2 . The desorption yields of these gases are described in this paper. An interlock system for the purpose of vacuum safety is also built in the system in order to increase the reliability of the vacuum operation. In the early stage of the commissioning, the malfunction of some ion gauges and quadrupole mass spectrometers were observed due to the beam interference. A solution has been found to reduce the interference.
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 08/1994; · 1.25 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Several different effects of water in vacuum systems were studied. An outgassing rate measurement system was used to measure outgassing rates for different venting conditions. Both diffusion and desorption phenomena were observed. The drier the venting gas, the more significant the diffusion behavior. From the pressure buildup tests, it was shown that the increasing H 2 O partial pressure is much less than that of the other gases. More effective surface pumping for water vapor than for the other gases is thought to be the reason. For the outgassing behaviors mentioned, an effort was made to describe the phenomenon quantitatively by using simple models. In addition to the behavior in the static vacuum, water vapor also shows an interesting behavior in the dynamic vacuum. A few results will be discussed.
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 08/1994; · 1.25 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: A 1.3 GeV synchrotron radiation storage ring is currently under
construction at SRRC. The installation activities had gone through about
one year, from March 1992 to March 1993. The commissioning of the
booster to storage ring (BTS) transfer line started from August 1992
soon after a 1.3 GeV synchrotron booster injector had been delivered in
July 1992. The intensive activities of the storage ring beam tests began
in April 1993. We had stored beam in April and some machine parameters
have been measured
Particle Accelerator Conference, 1993., Proceedings of the 1993; 06/1993
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[show abstract]
[hide abstract]
ABSTRACT: The design, fabrication and primary testings of the SRRC vacuum system are described. Aluminum‐alloy is chosen as the vacuum chamber material due to its high thermal conductivity, easy fabrication, low outgassing rate and other benefits. A computer simulation for the outgassing rate and pressure distribution was made to determine the locations and pumping speeds of the pumps. For evacuation, oil‐less turbomolecular pump systems, ion pumps and getter pumps are used. A ‘‘concentrated+DIP’’ pumping method is applied in the bending chamber to get efficient pumping. An oil‐less machining process and a special extrusion method are applied to fabricate the bending chamber and the straight chamber, respectively. Surface analysis method showed that the surface made by these processes are less contaminated. A static vacuum of <1×10−10 Torr was reached in an one‐sixth ring vacuum system after a bakeout at ∼130 °C for 24 hours. In order to minimize deformation, careful welding processes are performed. Smooth beam duct cross section is designed for reducing RF impedance.
AIP Conference Proceedings. 08/1991; 236(1):173-182.
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[show abstract]
[hide abstract]
ABSTRACT: The pumping speeds of a triode ion pump with an A1100 aluminum cathode were measured for N 2 , O 2 , H 2 , and Ar gases. In addition, results from a pumping lifetime test, a gettering test, x‐ray diffraction analysis, and Auger electron spectroscopy surface analysis were studied to understand the pumping mechanism for N 2 gas in the pump. It was shown that the interaction between aluminum and nitrogen with sufficient energy might occur in the ion pump. This kind of interaction would probably be the major pumping mechanism for nitrogen in an ion pump with an aluminum cathode.
Journal of Vacuum Science & Technology A Vacuum Surfaces and Films 02/1988; · 1.25 Impact Factor
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T T Yang,
K T Hsu,
S Y Hsu,
K B Liu,
C S Fann, Y C Liu,
H M Shih,
M S Yeh,
W K Lau,
A P Lee,
C C Liang,
J Y Hwang,
K K Lin,
Hsinchu Taiwan
[show abstract]
[hide abstract]
ABSTRACT: A single cell rf-gun cavity is designed and fabricated for the purpose of examining the feasibility of installing a thermionic rf-gun at NSRRC instead of a photocathode rf-gun considered previously. The operating frequency of the rf-gun cavity is set at 2856 MHz in order to utilize the available XK-5 klystron and linac. The fabricated parts of the OFHC copper cavity are brazed together in-house and then the cavity is characterized by rf measurement. It shows that the cavity gives very good character in terms of high quality factor, relaxed tuning range, adequate coupling coefficient, and reasonable reproducibility. The properties of the cavity are further explored by measuring the field profile and its response to an rf pulse in which the filling time is deduced. The measurement results of this brazed cavity are described and summarized in this report.
