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1.
Using the China Spallation Neutron Source(CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H-beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss,an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized. 相似文献
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针对质子治癌直线加速器功耗少、长度短的要求,设计了一台工作频率为324 MHz的漂移管型质子直线加速器(DTL)。该DTL把粒子从2.5 MeV加速到7 MeV,功耗为265 kW, 总长1.9 m。横向聚焦采用FODO结构,漂移管内放置永磁铁。提出一种新的束流匹配方案,在射频四极场加速器(RFQ)与DTL之间不设束运线,而是以 DTL入口处的4个单元为匹配段,把RFQ出口处相椭圆匹配到DTL周期结构入口处的相椭圆。 用PARMILA程序对该DTL进行了动力学模拟,结果表明该方案的束流发射度增长很小。 相似文献
3.
针对质子治癌直线加速器功耗少、长度短的要求,设计了一台工作频率为324 MHz的漂移管型质子直线加速器(DTL)。该DTL把粒子从2.5 MeV加速到7 MeV,功耗为265 kW, 总长1.9 m。横向聚焦采用FODO结构,漂移管内放置永磁铁。提出一种新的束流匹配方案,在射频四极场加速器(RFQ)与DTL之间不设束运线,而是以 DTL入口处的4个单元为匹配段,把RFQ出口处相椭圆匹配到DTL周期结构入口处的相椭圆。 用PARMILA程序对该DTL进行了动力学模拟,结果表明该方案的束流发射度增长很小。 相似文献
4.
To study the new RF control methods, a mathematic model of the RF system for the normal conducting linac is built and implemented with the software of Matlab. The model contains some typical units of the RF system, such as the klystron, the SLED and the traveling wave accelerating tube. Finally, the model is used to study the working point of the SLED and the adaptive feed forward algorithm for the RF control system. Simulation shows that the model works well as expected. 相似文献
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In a long-term planning for neutrino experiments in China, a medium baseline neutrino beam is proposed which uses a continue wave (CW) superconducting linac of 15 MW in beam power as the proton driver. The linac will be based on the technologies which are under development by the China-ADS project, namely it is also composed of a 3.2 MeV normal conducting RFQ and five different types of superconducting cavities. However, the design philosophy is quite different from the China-ADS linac because of the much weaker requirement on reliability here. The nominal design energy and current are 1.5 GeV and 10 mA, respectively. The general considerations and preliminary results on the physics design will be presented here. In addition, the alternative designs such as 2.0 GeV and 2.5 GeV, which may be required by the general design, can be easily extended from the nominal one. 相似文献
7.
Design details of a 100 MeV proton linear accelerator (Alvarez system) operating at a resonating frequency of 400 MHz have
been studied. Increase in the linac operating frequency has become feasible with the possibility of injecting protons from
a radio frequency quadrupole accelerator with energies higher than the conventional pre-injectors. Various electrical parameters
of such a system have been calculated and compared with the existing linac injectors operating at 200 MHz. 相似文献
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We present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear accelerator (linac), which has been recently built and successfully operated at Raja Ramanna Centre for Advanced Technology, Indore. The accelerating structure is a 2π/3 mode constant impedance travelling wave structure, which comprises travelling wave buncher cells, followed by regular accelerating cells. The structure is designed to accelerate 50 keV electron beam from the electron gun to 10 MeV. This paper describes the details of electromagnetic design simulations to fix the mechanical dimensions and tolerances, as well as heat loss calculations in the structure. Results of design simulations have been compared with those obtained using approximate analytical formulae. The beam dynamics simulation with space charge is performed and the required magnetic field profile for keeping the beam focussed in the linac has been evaluated and discussed. An important feature of a travelling wave linac (in contrast with standing wave linac) is that it accepts the RF power over a band of frequencies. Three-dimensional transient simulations of the accelerating structure along with the input and output couplers have been performed using the software CST-MWS to explicitly demonstrate this feature. 相似文献
10.
给出10MeV质子等时性回旋加速器的等时性磁场设计,中心区的设计以及加速后最终的束流品质,该加速器可作为正电子断层扫描装置的配套设备,用于生产中短寿命放射性同位素等.它沿半径方向只用一套线圈励磁,等时性磁场的建立完全由磁极形状决定.中心区的设计满足了轨道中心化的要求,并给出较大的横向和纵向接受度,以获得足够的束流强度. 经过172圈加速后,最终的束流品质满足要求. 相似文献
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In this paper, the 2-D electrostatic field software, POISSON, is used to calculate the characteristic impedance of a BPM (beam position monitor) for a high current proton linac. Furthermore, the time-domain 3-D module of MAFIA with a beam microbunch at a varying offset from the axis is used to compute the induced voltage on the electrodes as a function of time. Finally, the effect of low β beams on the induced voltage, the sensitivity and the signal dynamic range of the BPM are discussed. 相似文献
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In this paper, the 2-D electrostatic field software, POISSON, is used to calculate the characteristic impedance of a BPM (beam position monitor) for a high current proton linac. Furthermore, the time-domain 3-D module of MAFIA with a beam microbunch at a varying offset from the axis is used to compute the induced voltage on the electrodes as a function of time. Finally, the effect of low 13 beams on the induced voltage, the sensitivity and the signal dynamic range of the BPM are discussed. 相似文献
14.
The Beijing X-ray Energy Recovery Linac (BXERL) test facility is proposed in Institute of High Physics (IHEP). In this proposal, the main linac requires the injector to provide an electron beam with 5 MeV energy and 10 mA average current. An injector based on DC gun technology is the first candidate electron source for BXERL. However, the field emission in the DC gun cavity makes it much more difficult to increase the high voltage to more than 500 kV. Another technology based on a 217 MHz normal conducting RF gun is proposed as the backup injector for this test facility. We have designed this RF gun with 2D SUPERFISH code and 3D MICROWAVE STUDIO code. In this paper, we present the optimized design of the gun cavity, the gun RF parameters and the set-up of the whole injector system. The detailed beam dynamics have been done and the simulation results show that the injector can generate electron bunches with RMS normalized emittance 1.0 uppi mmcdotmrad, bunch length 0.77 mm, beam energy 5.0 MeV and energy spread 0.60%. 相似文献
15.
Development of a 100 MeV CW proton LINAC has been planned at CAT. This LINAC will be needing CW rf power in the frequency
ranges of 350 MHz and 700 MHz for its RFQ and DTL/CCDTL/SFDTL structures respectively. The power to the accelerating structures
will be produced by either 1 MW CW or 250 kW CW klystrons/inductive output tubes (HOM IOTs). The power needed by respective
feed points in the structure is max. 250 kW which will be powered by splitting the power from 1 MW klystron/klystrode into
four channels by using a wave-guide system. In case of using 250 kW tubes the power to the structures will be provided directly
from each tube. Two types of wave-guide transmission system have been considered, viz, WR 2300 for 350 MHz rf needs and WR
1500 for 700 MHz rf needs. The typical wave-guide system has been designed using the 1 MW CW klystron followed by wave-guide
filter, dual directional coupler, high-power circulator, three 3 dB magic TEE power dividers to split the main channel into
four equal channels of 250 kW each. Each individual channel has dual directional couplers, flexible wave-guide sections and
high power ceramic vacuum window. The circulator and each power divider is terminated into the isolated ports by high power
CW loads. Out of the four channels three channels have phase shifters. Present paper describes the technological aspects and
design specifications-considerations for these stringent requirements. 相似文献
16.
提出了一种利用单个谐振腔测量直线加速器束团长度的新方法。不同于传统的双谐振腔束团长度监测器,该方法仅需要使用单个谐振腔,省去了用于辅助测量的参考腔,从而简化了装置结构,节省了空间。针对国家同步辐射实验室基于可调谐红外激光的能源化学研究大型实验装置进行了监测器的物理设计。通过设定同轴探针的插入位置,解决了双模信号互相干扰的问题,利用微扰金属改变调节工作频率,克服了双模难以同时谐振的困难。利用CST软件进行建模和仿真。仿真结果表明,该监测器可实现2~5 ps束团长度的诊断,测量误差小于5%。 相似文献
17.
Electrochemical, optical and thermal characterisation of a proton conducting polymer system based on poly(2-acrylamido-2 methyl-propane-sulfonic
acid) (Poly-AMPS) for use in electrochromic windows is reported. The polymer electrolyte has been obtained by cross-linking
branched poly(ethylene imine) with the 2-acrylamido-2 methyl-propane-sulfonic acid.
The conductivity of the poly-AMPS films is influenced by the water content in the membrane and can vary between 10−4 and 10−7 Ω−1 cm−1. A minimum activation energy of 17±3 kJ/mol is estimated by a simple Arrhenius model. Poly-AMPS is very sensitive to the
humidity in the surroundings and electrochromic windows should be sealed if poly-AMPS is used. Temperatures above 45–50 °C
give increasing cracks in the polymer and loss of adhesion to the electrode surface.
Paper presented at the 4th Euroconference on Solid State Ionics, Renvyle, Galway, Ireland, Sept. 13–19, 1997 相似文献
18.
《Solid State Ionics》1999,116(1-2):99-104
Electrochemical regulation of hydrogen partial pressure in flowing gas was examined using a proton-conducting ceramic tube made of Yb-doped SrCeO3. Hydrogen partial pressure in the test gas was controlled by electrochemical hydrogen pump. When pumping current was controlled based on the Faraday's law, hydrogen content in the test gas with a constant flow-rate was well regulated, while change in flow-rate of the gas caused some deviation of hydrogen partial pressure from that desired. The pumping current could be determined in a self-correcting manner, which was efficient to regulate gas even with changes in flow-rate and/or initial hydrogen content in the gas. 相似文献
19.
在硼中子俘获治疗(BNCT)装置中,束流整形体(BSA)的作用是将中子源产生的快中子束流慢化至超热中子能区(0.5 eVE10 keV),并尽可能减弱快中子、热中子和γ射线的成分,同时保证中子的方向性,其设计与优化是BNCT装置设计工作的核心内容之一.本文采用3.5 MeV,10 mA的质子束轰击锂靶,由核反应~7Li(p,n)~7Be产生的中子为源项,针对BSA的慢化体材料和结构、γ屏蔽层和热中子吸收层的厚度等参数进行蒙特卡罗模拟设计与优化.研究发现,采用Fluental和LiF两种慢化材料间隔2 cm层状堆叠的三明治BSA构型,在保证快中子剂量成分(D_f/φ_(epi)),γ剂量成分(D_γ/φ_(epi))和热中子比例φ_(th)/φ_(epi)满足IAEA-TECDOC-1223报告推荐要求的同时,在BSA出口处超热中子注量率优于单独使用Fluental和单独使用LiF的BSA设计.BSA出口处修正的Synder人头几何模型中的剂量分布计算结果显示:上述三明治构型的深度剂量分布与单独使用Fluental材料构型的结果基本相当,优于单独使用LiF构型,表明Fluental和LiF层状堆叠的三明治BSA构型是一种可行的BSA结构. 相似文献
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