Institutional Repository of Institute of Modern Physics, CAS
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TRANSMISSION EFFICIENCY STUDY OF SSC
No full textTransmission efficiency of HIRFL-SSC had been<br />studied, found the main reasons of the lower<br />transmission efficiency, and some advices were put<br />forward to improve the transmission efficiency
AUTOMATED OPERATION AND OPTIMIZATION OF THE VARIAN 250 MeV SUPERCONDUCTING COMPACT PROTON CYCLOTRON
No full textThe 250 MeV superconducting compact proton<br />cyclotron of Varian Medical Systems Particle Therapy is<br />specially designed for the use within proton therapy<br />systems. During medical operation typically no operator<br />is required. Furthermore, several automated control<br />system procedures guarantee a fast, simple and reliable<br />startup as well as beam optimization after overnight<br />shutdown or regular service actions. We report on the<br />automated startup procedures, automated beam centering<br />and automated optimization of extraction efficiency.<br />Furthermore we present an automated beam current<br />setting as used during medical operation by means of an<br />electrostatic deflector located at the cyclotron center at<br />low beam energies.IMP;Chinese Academy of Science
PRESENT OPERATIONAL STATUS OF NIRS CYCLOTRONS (AVF930, HM18)
No full textSince Japanese government launched a new program of<br />the “Molecular Imaging Research Program” in 2005, the<br />NIRS AVF930 cyclotron has been mainly operated to<br />produce radio-isotopes together with a small cyclotron<br />(HM18) for PET imaging. There are also machine<br />operations of the AVF930 for physical experiments and<br />tests of radiation damage on electric devices. To carry out<br />cyclotron operations for these purposes, some<br />improvements have been done in the facility. In this report,<br />we will present recent operational status of the NIRS<br />cyclotron facility (AVF930, HM18), and its improvement<br />points.IMP;Chinese Academy of Science
BEAM EXTRACTION SYSTEM DESIGN FOR CYCIAE-14
No full textconstruction at CIAE (China Institute of Atomic Energy).<br />H- ion will be accelerated in this cyclotron and proton<br />beam will be extracted by carbon strippers in dual<br />opposite direction. Two stripping points are chosen in<br />each extracting direction to extract proton beams to<br />different targets to extend the use of the machine and the<br />stripping points can be selected only by rotating the<br />stripping foil. Two modes have been considered of the<br />extraction system, one is designed to be installed on the<br />wall of the vacuum chamber, the other is designed to be<br />inserted vertically from the sector poles. Final choice will<br />depend on the agility, the simpleness and the results of the<br />experimentation. The angle between the stripper and the<br />beam orbit is optimized to improve the extracted beam<br />quality. Numerical simulation shows the two stripping<br />points, the beam orbit and the beam characteristic at each<br />extraction direction. The optimized azimuth of the<br />stripper is also presented in this paper to show its<br />influence for the beam quality. Based on the concept<br />design, the mechanical design and the correlative<br />experimentation have been done; the results are shown in<br />the paper.IMP;Chinese Academy of Science
MODIFICATION OF THE CENTRAL REGION IN THE RIKEN AVF CYCLOTRON FOR ACCELERATION AT THE H=1 RF HARMONIC
No full textA highly advanced upgrade plan of the RIKEN AVF<br />cyclotron is under way. The study is focused on the<br />formulation of the new acceleration regimes in the AVF<br />cyclotron by detailed orbit simulations. The extension of<br />the acceleration energy region of light ions towards higher<br />energies in the existing RF harmonic equal to 2 and the<br />modification of the central geometry for the RF harmonic<br />equal to 1 to allow an acceleration of protons at several<br />tens of MeV are considered. The substantial redesign of<br />the central electrode structure is needed to accelerate<br />protons with reasonable values of the dee voltage. The<br />new inflector geometry and the optimized central<br />electrode structure have been formulated for the upgrade.IMP;Chinese Academy of Science
MEDICAL CYCLOTRON AND DEVELOPMENT IN CHINA
No full textThe first medical cyclotron CYCIAE-30 in China has
been designed and constructed by China Institute of
Atomic Energy (CIAE), and its construction was finished
in 1995. Since then, medical cyclotron got developed in
China, several cyclotrons had been constructed, and some
medical experiments and practice had been done with
those cyclotrons. Now medical cyclotron develops even
quickly in China, several medical cyclotrons are under
design and construction. Meantime, a compact cyclotron
virtual prototyping was developed to help the cyclotron
design and reduce cyclotron R & D cost.IMP;Chinese Academy of Science
AMPLIFIER TEST STAND FOR THE CRM CYCLOTRON
No full textThe final stage amplifier stability has proved to be an
important issue in the commissioning of CRM cyclotron
at CIAE. An air cooled 4CX15,000 tube final amplifier
was designed to evaluate the anode circuit and
neutralization, both of which are weak points of the CRM
cyclotron amplifier. Instead of strip line, the new designed
anode structure adopts coaxial form, resulting less chance
of parasitic resonance in the circuits. A tuneable
neutralization circuits was also included in the design,
giving an opportunity to fine tune in high power
operations. First, the instability in CRM RF system will
be analyzed in this paper, followed with the new amplifier
designs including the tube operating line calculations,
input/output circuits designs and finite integral
simulations. The mechanical design for tube socket and
anode tank were successfully carried out using the data
provided in this paper. The final stage amplifier was then
manufactured, assembled and commissioned. In the
power test with dummy load, more than 9.2kW RF
fundamental power was provided at the frequency of
44.5MHz.IMP;Chinese Academy of Science
STUDY ON PXI AND PAC-BASED HIL SIMULATION CONTROL SYSTEM OF CYCHU-10 CYCLOTRON
No full textUsing the technology of hardware in loop (HIL),
control system simulation model of the CYCHU-10
cyclotron is developed with real-time, simulation and
statechart module under the LabVIEW environment. A
prototyping design method based on NI PXI operation
condition virtual platform and PAC controller is presented.
The result indicates that the platform is feasible and
effective in completing control system test under
hardware virtual environment and shortening
development time.IMP;Chinese Academy of Science
EXPERIMENT AND ANALYSIS: PARTIAL LOSS OF INSULATION VACUUM IN K-500 SUPERCONDUCTING CYCLOTRON CRYOSTAT
No full textAt higher currents in superconducting coil of the K500
superconducting cyclotron, it was found that the
insulation vacuum surrounding the LHe vessel deteriorate
with increasing current in the coil and finally leading to
slow dump of the coil. This is a limitation for further
increasing current value in the magnet coil. On the other
hand, once the current value was returned to zero, vacuum
reading reaches to its initial value. Experiment and
analysis have been done to quantify the contribution of
molecular gas conduction (FMGC) on heat load because
of this partial loss of insulation vacuum. Experiment was
also performed to find out how much betterment in terms
of heat load is possible by incorporating an additional
vacuum pump.
The cryostat safety analysis because of the loss of
insulation vacuum has become very important at this new
scenario. An analysis has been done to know what could
be the maximum pressure rise with time in case of loss of
vacuum. This data has been used to know what should be
the relieving mass flow rate to avoid any pressure burst
accident. Finally this data has been compared with the
existing relief valve. It is found that the existing safety
system can take care of total loss of insulation vacuum
scenario.IMP;Chinese Academy of Science
INFLUENCE OF RF MAGNETIC FIELD ON ION DYNAMICS IN IBA C400 CYCLOTRON
No full textMagnetic components of RF field in C400 [1] cyclotron,
being under development by IBA, makes noticeable
influence on ion dynamics.
In particular, increase in the dee voltage [2] along
radius leads to essential phase compression of a bunch. At
the same time RF magnetic field changes a central ion
phase by only 2ºRF.
Calculations have also shown that RF magnetic field
makes visible but pretty small influence on the radial
motion, while an impact of the RF magnetic field on the
axial motion has not been detected.
The results are compared for the two RF magnetic field
maps: (i) calculated numerically by Microwave Studio
and, (ii) calculated analytically from RF electric field map
by means of Maxwell’ equations.IMP;Chinese Academy of Science