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Abstract: The Peking University Neutron Imaging Facility (PKUNIFTY) is being constructed, which is a compact acceleratordriven neutron source. The accelerator is a radio frequency quadrupole (RFQ) accelerator, which can deliver a 2 MeV deuteron beam. The neutrons are generated by deuterons bombarding beryllium target. The accelerator facility mainly consists of ECR (electron cyclotron resonance) ion source, LEBT (low energy beam transportation), RFQ cavity, HEBT (high energy beam transportation), RF transmitter and control system. This paper will introduce the requirements and design of that accelerator facility. [Copyright &y& Elsevier]

Abstract: The better contrast sensitivity and resolution of neutron radiographs require higher neutron flux and enough L/D. The neutron yield of compact accelerator-driven neutron sources is usually lower than reactor and spallation neutron sources. It is difficult to obtain the high L/D and the high neutron flux simultaneously. The deuteron beam and Be target were selected for Peking University neutron imaging facility (PKUNIFTY), which can give higher neutron yield at lower beam energy. That means smaller facility size and lower power consumption in the accelerator, and therefore the lower cost. But that reaction also gives higher yield, so how to realize higher n/ratio is another issue. For intense deuteron beam the deuterons lost in the structure materials may become target atoms and generate neutrons under the bombardment of the succeeded beam. This paper will discuss the above problems, and introduce the PKUNIFTY design, which tried to reach a compromise among the various conflicting demands and meet the basic requirements of neutron radiography. [Copyright &y& Elsevier]

Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40keV to 500keV. As a specific feature, the output beam energy spread is as low as 0.6% achieved with the internal discrete bunching method, which makes potential applications of RFQ feasible, such as accelerator mass spectrometry and ion implantation. Tolerances of the beam dynamics design are studied by means of changing the input beam parameters, and the results are quite satisfying. On the other hand, the L-IH-RFQ structure is employed, taking advantage of its mechanical stability and the absence of inter-electrode voltage asymmetry. Radio-frequency properties are studied and optimized for reducing power loss with Microwave Studio (MWS). Tuning of the field flatness and frequency is investigated in principle. [ABSTRACT FROM AUTHOR]