Institutional Repository of Institute of Modern Physics, CAS
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Experimental studies of the dissociative recombination of CD3CDOD+ and CH3CH2OH2+
No full textAims. We determine branching fractions, cross sections and thermal rate constants for the dissociative recombination of CD3CDOD+ and CH3CH2OH2+ at the low relative kinetic energies encountered in the interstellar medium. Methods. The experiments were carried out by merging an ion and electron beam at the heavy ion storage ring CRYRING, Stockholm, Sweden. Results. Break-up of the CCO structure into three heavy fragments is not found for either of the ions. Instead the CCO structure is retained in 23 +/- 3% of the DR reactions of CD3CDOD+ and 7 +/- 3% in the DR of CH3CH2OH2+, whereas rupture into two heavy fragments occurs in 77 +/- 3% and 93 +/- 3% of the DR events of the respective ions. The measured cross sections were fitted between 1-200 meV yielding the following thermal rate constants and cross-section dependencies on the relative kinetic energy: sigma(E-cm[eV]) = 1.7 +/- 0.3 x 10(-15)(Ecm[eV])(-1.23 +/- 0.02) cm(2) and k(T) = 1.9 +/- 0.4 x 10(-6)(T/300)-0.73 +/- 0.02 cm(3) s(-1) for CH3CH2OH2+ as well as k(T) = 1.1 +/- 0.4 x 10(-6)(T/300)(-0.74 +/- 0.05) cm(3) s(-1) and s(Ecm[eV]) = 9.2 +/- 4 x 10(-16)(Ecm[eV])-1.24 +/- 0.05 cm(2) for CD3CDOD
CONTROL SYSTEM OF CRYOGENIC PLANT FOR SUPERCONDUCTING CYCLOTRON AT VECC
No full textCryogenic Plant of Variable Energy Cyclotron Centre<br />consists of two Helium refrigerators (250W and 415W @<br />4.5K), valve box with sub-cooler and associated sub<br />systems like pure gas storage, helium purifier and impure<br />gas recovery etc. The system also consists of 3.1K liters<br />of liquid Nitrogen (LN2) storage and delivery system. The<br />plant is designed to cater the cryogenic requirements of<br />the Superconducting Cyclotron. The control system is<br />fully automated and does not require any human<br />intervention once it is started. EPICS (Experimental<br />Physics and Industrial Control System) architecture has<br />been adopted to design the Supervisory control and data<br />acquisition (SCADA) module. The EPICS Input Output<br />Controller (IOC) communicates with four Programmable<br />Logic Controllers (PLCs) over Ethernet based control<br />LAN to control/monitor 618 numbers of field Inputs/<br />Outputs(I/O). The plant is running very reliably round the<br />clock, however, the historical data trending of important<br />parameters during plant operation has been integrated to<br />the system for plant maintenance and easy diagnosis. The<br />400 KVA UPS with 10 minutes back up time have been<br />installed to keep the cryogenic system running with one<br />160KW cycle compressor during utility power<br />interruptions
BEAM EXTACTION SYSTEM FROM DC60 CYCLOTRON
No full textThe results of numerical simulation of the heavy ions<br />beam extraction system (A/Z=6÷12, W=0.35÷1.77<br />MeV/amu) from the DC60 cyclotron are presented. The<br />parameters of the extraction system elements<br />(electrostatic deflector and focusing magnetic channel)<br />and diagnostic elements are chosen. The experimental<br />extraction efficiency of 14N2+ and 84Kr12+ beams<br />is equal to 60÷65% with intensity 1.5÷2.5 μA.IMP;Chinese Academy of Science
PHYSICS DESIGN OF CYCIAE-70 EXTRACTION AND BEAMLINE SYSTEM
No full textA driver with beam power of 50KW (70 MeV, 0.75 mA)<br />based on compact H-/D- cyclotron, CYCIAE-70, has been<br />designed at CIAE in Beijing for the RIB production and<br />application in the nuclear medicine recently. CYCIAE-70<br />is designed to be a dual particle cyclotron and it is able to<br />deliver proton with energy in the range 35~70 MeV and<br />deuteron beam with energy in a range of about 18~33<br />MeV. About 700μA for H+ and 40μA for D+ will be<br />extracted in dual opposite directions by charge exchange<br />stripping devices and the extraction beam energy is<br />continuously adjustable. The physics design of CYCIAE-<br />70 stripping system has been done and the optics<br />calculation for the extraction proton and deuteron beam<br />has been finished. The dispersion effects for the extracted<br />beam are analyzed and the beam parameters after<br />extraction are calculated. 6 beam transport lines and<br />experiment target stations are designed for different<br />applications. A wobbling magnet is used in one of the<br />beam transport lines, which will rotate the beam to form a<br />beam spot on the target with a size of Ф40mm and<br />uniformity of better than 95%.IMP;Chinese Academy of Science
BEAM TUNING IN KOLKATA SUPERCONDUCTING CYCLOTRON
No full textThe Superconducting cyclotron at VECC, Kolkata, has<br />accelerated ion beams up to extraction radius successfully<br />confirmed by the neutrons produced by the nuclear<br />reactions. The internal beam tuning process started with<br />beam parameters calculated using the measured magnetic<br />field data [1]. Due to some mechanical and electrical<br />problems we were forced to tune the beam with three<br />major trim coils off. Accurate positioning of central<br />region Dee-extensions ensuring the proper acceleration<br />gaps in the first turn was required for successful<br />acceleration of beam through the compact central region<br />clearing the posts in the median plane. Here we present<br />different aspects and results of initial beam tuning.IMP;Chinese Academy of Science
A COMPACT SOLUTION FOR DDS-GENERATOR, TURN-ON AND PROTECTIONS IN RADIO FREQUENCY ACCELERATOR SYSTEMS
No full textOne single compact rack includes: Direct Digital<br />Synthesizer (RF-generator), turn-on and protection<br />devices. The system synthesizes a highly stable RF signal<br />up to 120 MHz, turns the power on in the RF cavities<br />through a step-ramp modulator, and protects the RF<br />system against mismatching, sparks and multipactoring. A<br />first prototype has been designed, assembled and tested<br />on the RF system of the k-800 superconducting cyclotron<br />at Infn-Lns. The hardware, the software, and the<br />preliminary test results, are shown in this paper. This<br />solution is part of the new computer-based RF control<br />systemIMP;Chinese Academy of Science
RF CAVITY SIMULATIONS FOR SUPERCONDUCTING C400 CYCLOTRON
No full textThe compact superconducting isochronous cyclotron<br />C400 [1] has been designed by IBA (Belgium) in<br />collaboration with the JINR (Dubna). It will be the first<br />cyclotron in the world capable of delivering protons,<br />carbon and helium ions for therapeutic use.<br />12C6+and4He2+ ions will be accelerated to the energy of 400 MeV/uenergy and extracted by electrostatic deflector, H2<br />+ ionswill be accelerated to the energy of 265 MeV/u and<br />extracted by stripping. It is planned to use two normal<br />conducting RF cavities for ion beam acceleration in<br />cyclotron C400. Computer model of the double gap delta<br />RF cavity with 4 stems was developed in is a generalpurpose<br />simulation software CST STUDIO SUITE.<br />Necessary resonant frequency and increase of the voltage<br />along the gaps were achieved. Optimization of the RF<br />cavity parameters leads us to the cavity with quality factor<br />about 14000, RF power dissipation is equal to about<br />50 kW per cavity.IMP;Chinese Academy of Science
BNCT SYSTEM USING 30 MEV H- CYCLOTRON
No full textKyoto University and Sumitomo Heavy Industries, Ltd.
(SHI) have developed an accelerator-based neutron source
for Boron Neutron Capture Therapy (BNCT) at the Kyoto
University Research Reactor Institute (KURRI). In order
to obtain 109 n/cm2/sec epithermal neutrons for cancer
treatment, a newly designed 30 MeV H- AVF cyclotron
named HM-30 was constructed and is being operated.
With newly developed spiral inflector, the beam current in
the central region can exceed 2 mA. The cyclotron is
operated stably at 1 mA. Extracted proton beam is
expanded by two scanner magnets in order to moderate
heat concentration on the beryllium target, which is
directly cooled by water to endure 30 kW heat load. Fast
neutrons are emitted from the target, and moderated to
epithermal region by a moderator which consists of lead,
iron, polyethylene, etc. Thermal neutron flux in a water
phantom is measured by gold wire, which is consistent
with the calculation using MCNPX. Preclinical studies
are being carried out with 10B-p-Borono- phenylalanine
(BPA).IMP;Chinese Academy of Science
STATUS OF RIBF ACCELERATORS AT RIKEN
No full textRecent achievements and upgrade programs in the near
future at RIKEN Radioactive Isotope Beam Factory (RIBF)
are presented. The beam intensity and available ion species
are increasing at RIBF, owing to the continuous efforts that
have been made since the first beam in 2006. So far, we accelerated
deuteron, helium, nitrogen, oxygen, aluminum,
calcium, krypton, and uranium beams with the superconducting
ring cyclotron, SRC. The extracted beam intensities
reached 1,000 pnA for the helium and oxygen beams.
From the operational point of view, however, the intensity
of the uranium beam should be much increased. We are,
therefore, constructing a new injector linac for the RIBF,
consisting of a superconducting ECR ion source, RFQ, and
DTL, which will be commissioned in this fiscal year. By
using this injector, we also aim at independent operation
of the RIBF and GARIS facility for super-heavy element
synthesis.IMP;Chinese Academy of Science
