• J.-H. Jang, Y.-S. Cho, H.S. Kim, H.-J. Kwon
  KAERI, Daejon
• Y.Y. Lee
  BNL, Upton, Long Island, New York

As a feasible extension plan of the proton engineering frontier project (PEFP) 100-MeV proton linac, the conceptual design of an rapid cycling synchrotron (RCS) is under progress. The main purpose of the synchrotron is a spallation neutron source and it also includes the slow extraction option for basic and applied science research. In the initial stage, the beam power is 60 kW by using a scheme of 100-MeV injection and 1-GeV extraction. There is a scheme to increase power to 500 kW through a 3-stage upgrade. The injection and extraction energies will be 200-MeV and 2-GeV respectively after the final upgrade. This article summarizes the present status of the RCS design. It includes the physics design including injection and acceleration, and conceptual design of some magnets and RF cavity.

• H.-J. Kwon, E.-M. An, Y.-S. Cho, I.-S. Hong, J.-H. Jang, D.I. Kim, H.S. Kim, K. Min, B.-S. Park, K.T. Seol, Y.-G. Song, S.P. Yun
  KAERI, Daejon

The 20MeV proton accelerator has been operating since 2007 when it got an operational license at Korea Atomic Energy Research Institute (KAERI) by Proton Engineering Frontier Project (PEFP). Beam property such as an emittnace was measured at the low energy beam transport (LEBT) to characterize the beam into the RFQ. In addition, several parts were modified to test the adaptability of those which would be used for the 100MeV linac. The modulator for the 100MeV linac was installed and tested in the 20MeV linac test bench. In addition, low level RF (LLRF) system was modified in the overall configuration and the operator interface (OPI) with EPICS. In this paper, the beam property measurement results and modification of the linac are presented.

• H.S. Kim, Y.-S. Cho, H.-J. Kwon
  KAERI, Daejon
• S. An
  PAL, Pohang, Kyungbuk

A superconducting RF cavity with a geometrical beta of 0.42 and a resonant frequency of 700 MHz has been under investigation for an extension program of Proton Engineering Frontier Project (PEFP) to accelerate the proton beam above 100 MeV. We developed and tested a two-cell prototype in order to confirm the fabrication procedure and check the RF and mechanical properties of such a low-beta elliptical cavity. The prototype has been fabricated with high RRR niobium sheets (RRR > 250). Double-ring structure was adopted to reduce the Lorentz force detuning effect. For the vertical test of the prototype cavity, a cryostat was designed and fabricated. Operating temperature is 4.2 K, therefore, pumping to reduce the pressure is not required. We applied 40 layers of superinsulation around the helium vessel in addition to the vacuum insulation between the helium vessel and outer chamber. The status of the prototype development and RF test results will be presented in this paper.

• T.A. Trinh, Y.-S. Cho, I.-S. Hong, J.-H. Jang, H.S. Kim, H.-J. Kwon, H.R. Lee, B.-S. Park
  KAERI, Daejon

In the RF linac, the RF system is roughly half of the total cost. The 13.56MHz rf generator is cheap and readily available. Therefore, an rf implanter which uses a cavity operating at the frequency of 13.56MHz has now been considered and developed at Proton Engineering Frontier Project (PEFP) - Korea. The implanter consists of a Duoplasmatron ion source, a triplet focusing magnet, an rf cavity, a bending magnet and an end chamber. It can accelerate particles up to 32keV/u for charge to mass ratio of 1/4. The implanter design concept, fabrication, testing and commissioning are presented in this presentation.