This picture, 21KB

Fig. 10-2 Schematic drawing of the accelerator for neutron science research

Fig. 10-3 Ion source and RFQ 100 keV beams injected from an ion source were successfully accelerated by the RFQ to 2 MeV with 70 mA peak current, 1 msec pulse width, and 100 Hz frequency.

A high intensity proton accelerator forms the center of a Neutron Science Research Complex. Proton accelerators were originally developed for research of atomic nuclei. The applications have expanded and they have been utilized for research in a variety of fields. This has brought remarkable progress in accelerator development. Efforts to improve accelerator characteristics are still ongoing, even at present. The Neutron Science Research Complex required beam characteristics are that the energy be 1.5 GeV and the average current be 4-6 mA. Thus, the beam power will have an extremely high value, 8 MW. No previous accelerators have had such a high beam power. The accelerator that is being developed aims to achieve this power. Linear accelerators are best suited to accelerate high-current beams, since the beams are accelerated straight forward linearly and rapidly. The arrangement of the planned accelerator is shown in Fig. 10-2. The fundamental properties of the beam are mainly determined by the first accelerator section, from the ion source (IS) to the first drift tube linac (DTL). A test accelerator consistiong of an ion source and a radio-frequency quadrupole (RFQ) was fabricated, installed, and operated. The results of this test satisfied the initial specifications. The beam was injected with an energy of 100 keV from the ion source and was accelerated up to 2 MeV by the RFQ. The high-energy accelerator section, shown in Fig. 10-3, is the largest component of the accelerator. The most promising candidate for this section is a superconducting cavity because it has the advantage of requiring a less electricity and has excellent characteristics for accelerating high currents, such as a large aperture and a high accelerating gradient. An major effort has been made to design the cavity. The construction of a test stand for a superconducting accelerator cavity is progressing.

Reference K. Hasegawa et al., Proceedings of the 10th Symposium on Accelerator Science and Technology, JAERI-Conf 95-021 (1995).

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