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Yee-Rendon, B.
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.310 - 313, 2022/10
Accelerator-driven subcritical systems (ADS) offer an advantageous option for the transmutation of nuclear waste. ADS employs high-intensity proton linear accelerators (linacs) to produce spallation neutrons for a subcritical reactor. Besides the challenges of any megawatt proton machine, ADS accelerator must operate with stringent reliability to avoid thermal stress in the reactor structures. Thus, ADS linacs have adopted a reliability-oriented design to satisfy the operation requirements. This work provides a review and the present status of the ADS linacs in the world.
Fuwa, Yasuhiro; Moriya, Katsuhiro; Takayanagi, Tomohiro
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.364 - 367, 2022/09
MEBT1 (Medium Energy Beam Transport 1) of the J-PARC LINAC is a 3 MeV beam transport system located between the RFQ (Radio Frequency Quadrupole) and DTL (Drift Tube Linac). In the MEBT1, the beam-optical matching for injection into DLT and chopping for injection into acceleration phase of 3 GeV synchrotron, located downstream to the LINAC, are performed. The characteristics of MEBT1 are an important factor in determining the beam quality in the J-PARC accelerator facility. To achieve beam power of 1 MW and beyond, improving the stability and reliability of MEBT1 is an important development issue. The application of permanent magnets to the beam focusing system to the MEBT1 is under consideration to achieve improved stability and reliability. In this presentation, we report the design of focusing magnets using permanent magnet material and the results of the lattice study of MEBT1 with permanent magnets.
Tamura, Jun; Kondo, Yasuhiro; Yee-Rendon, B.; Meigo, Shinichiro; Maekawa, Fujio; Kako, Eiji*; Umemori, Kensei*; Sakai, Hiroshi*; Domae, Takeshi*
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.180 - 183, 2022/09
The Japan Atomic Energy Agency (JAEA) has proposed an accelerator-driven subcritical system (ADS) to efficiently reduce high-level radioactive waste generated at nuclear power plants. One of the challenging R&D aspects of ADS is the reliability of the accelerator. In preparation for the full-scale design of the CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single spoke cavity. Since there is no experience in Japan in manufacturing a superconducting spoke cavity, prototyping and performance testing of the cavity is essential to ensure the feasibility of the JAEA-ADS linac. In the Japanese fiscal year 2021, we have started welding cavity parts together. By preliminarily examining the electron beam welding conditions, each press-formed niobium part was joined with a smooth welding bead. At present, we have fabricated the cavity's body part.
