LINAC FOR THE COMPACT PULSED HADRON SOURCE PROJECT AT TSINGHUA UNIVERSITY BEIJING*

A project of the Compact Pulsed Hadron Source (CPHS) led by the Department of Engineering Physics of Tsinghua University in Beijing, China has been reported in this paper. CPHS consists of a proton linac, a neutron target station (a Be target, moderators and reflector), and a small-angle neutron scattering instrument, a neutron imaging/radiology station, and a proton irradiation station. INTRODUCTION In 2010 June, Tsinghua University, in order to respond the increasing demand in China of accelerator-based neutron and proton experimental platforms for basic researches and technological developments, startup a project of building a Hadron Application and Technology Complex (HATC) which begins with a relatively small and moderate-power facility but later expandable. The initial phase of the HATC is called the Compact Pulsed Hadron Source (CPHS)[1]. The missions of CPHS are Education Student & staff training; Instrumentation and R&D; Neutron instrumentation tests; Limited-scale science discovery & applications with neutron imaging & scattering instruments. It will be completed as soon as possible in 3 years. CPHS consists of a proton linac (13 MeV, 16 kW, peak current 50 mA, 0.5 ms pulse width at 50 Hz), a neutron target station, a small-angle neutron scattering instrument, a neutron imaging/radiology station and a proton irradiation station. Currently, progress of the project is under constructed. The initial phase of the CPHS construction is scheduled to complete in the end of 2012. The accelerator part consists of a ECR ion source. LEBT section, a RFQ accelerator, a DTL linac and a HEBT. ECR ion source will give up to 60mA at 50keV proton beam with proton ration large than 85%, and 0.02 πcm mrad normalized emittance. A very short length of LEBT will be used to matching the beam from ion source to the RFQ entrance. An 3 meters long of RFQ machine can accelerate the proton to 3MeV. No MEBT will be requirement in this project. The Drift Tube Linac with permanent magnets focusing lens will accept the proton beam direct from RFQ. A 4.3 meters length of DTL with 43 cells will accelerate the beam up to 13MeV and the HEBT section will transport the proton beam from output of DTL to the target inside the target station centre with 3.5cmX3.5cm uniform distribution on the Be target. The main parameters of CPHS are listed in Table 1. Figure 1 shows the CPHS facility layout. Table 1: CPHS Primary Design Parameters Species proton Proton power on target (kW) 16 Proton energy (MeV) 13 Average beam current( mA) 1.25 Pulse repetition rate( Hz) 50 Protons per pulse 1.56x10 Pulse length (ms) 0.5 Peak beam current( mA) 50