Dewa, Hideki

Fujita, Hirokazu

Ikegami, Masanori

Inoue, Makoto

Iwashita, Yoshihisa

Kakigi, Shigeru

Kando, Masaki

Mashiko, Katsuo

Noda, Akira

Okamoto, Hiromi

Shirai, Toshiyuki

Sugimura, Takeshi

Tonguu, Hiromu

Kyoto University Research Information Repository

TitleConstruction of 100 MeV Electron Linac (NUCLEARSCIENCE RESEARCH FACILITY - Particle and PhotonBeams)Author(s)Shirai, Toshiyuki; Sugimura, Takeshi; Kando, Masaki;Ikegami, Masanori; Iwashita, Yoshihisa; Okamoto, Hiromi;Kakigi, Shigeru; Dewa, Hideki; Tonguu, Hiromu; Fujita,Hirokazu; Noda, Akira; Mashiko, Katsuo; Inoue, MakotoCitationICR annual report (1996), 2: 54-55Issue Date1996-03URL http://hdl.handle.net/2433/65696RightType ArticleTextversionpublisherKyoto University54 ICRAnnual Report, Vol. 2, 1995Construction of 100 MeV Electron LinacToshiyuki Shirai, Takeshi Sugimura, Masaki Kando, Masanori Ikegami,Yoshihisa Iwashita, Hiromi Okamoto, Shigeru Kakigi, Hideki Dewa, Hiromu Tonguu,Hirokazu Fujita, Akira Noda, Katsuo Mashiko and Makoto InoueAn electron linear accelerator has been constructed as an injector of the storage ring. The output beamenergy of the linac is 100 MeV and the designed beam current is 100 rnA at the pulse width of 1 ,"",sec.The construction of the linac has been finished and we succeeded to accelerate the electron beam of 140rnA in October, 1995. The precise measurements of the beam parameters are now going.Keywords: Linear Accelerator/ Synchrotron Radiation/ disc-loaded structure/ klystronTable 1. Main parameters of the electron beam.field is 45 MV per one accelerating structure with-out beam loading at the input power of 20 MW.The RF frequency is 2857 MHz and the main RFamplifier is a klystron (ITT-8568). The maximum out-put power is 21 MW and the RF pulse width is 2flsec. The stabilized power supply for the klystronmodulator is used to keep the klystron power and theoutput beam energy. The klystron voltage stability isless than 3x10-3•Figure 2 shows the input RF power of the thirdaccelerating structure and the accelerated beampulse. The RF power is 20 MW and the beam currentis 140 rnA.A compact electron storage ring (Kaken StorageRing, KSR) and the linear accelerator are now underconstruction at the Institute for Chemical Research(1),(2). The layout of the accelerators is shown in Fig.1. The maximum beam energy of the KSR is 300MeV. It will be used as the synchrotron radiationsource from the dipole magnet and the insertiondevice. The critical wave length is 17 nm.The electron linac is composed of an electron gun,a buncher and three accelerating structures. The out-put beam energy is 100 MeV. It will be used for thebeam injection to the KSR and the experiments usingthe 100 MeV electron beam.The electron gun is a Pierce type gridded gun. Themaximum extraction voltage is -100 kV. The phasespread of the beam is reduced by the pre-buncher andthe buncher. The designed phase spread of is within 3degree at the beam current of 100 rnA when the inputpower is 12 MW. The main accelerating structure is adisc-loaded one and a traveling wave type. The electricEnergyBeam CurrentPulse WidthMaximum Repetition100 MeV100 rnA1 flsec20 HzNUCLEAR SCIENCE RESEARCH FACILITY -Particle and Photon Beams-Scope ofResearchParticle and photon beams generated with accelerators and their instrumentations both for fundamentalresearch and practical applications are studied. The following subjects are being studied: beam dynamicsrelated to the space charge force in the accelerators: beam handling during the injection and extractionprocesses of the accelerator ring: radiation mechanism ofphoton by electrons in the magnetic field: interac-tions in the few-nucleon systems: R&D to realize a compact proton synchrotron dedicated for cancer therapy:and irradiation ofmaterials with particle and photon beams.NODA, KAKIGI, SHIRAI TONGUUProfessorNODA, Akira (D Sc)Associate ProfessorKAKIGI, Shigeru(D Sc)InstructorSHIRAI ToshiyukiTechnicianTONGUU HiromuLecturer (part-time)KITAMURA, Hideo(Prof of NationalLaboratory for High Energy Physics, KEK/The Institute of Physical and ChemicalResearch, RIKEN)StudentsIKEGAMI,Masanori (DC)KANDa, Masaki (DC)SUGIMURA, Takashi (MC)KIHARA, Takahiro (MC)ICRAnnual Report, Vol. 2, 1995 55References1. T.Shirai, Bull. Inst. Chern. Res., Kyoto Univ., 73,No.1, 1995, p78.2. A. Noda, Bull. Inst. Chern. Res., Kyoto Univ., 73,No.1, 1995, p27././/'Beam pulseBeamDumpQuadrupoleMagnctNo.5Electron Strage RingQuadrupoleMagnet No.4QuadrupoleMagnctNo.1SmElectron LinacOptical Beam CourseBuncher Acceleralor No.1 Accelerator No.2Figure 1. Layout of the linac and the KSR.Figure 2. Input RF pulse of the third acceleratingstructure and the accelerated beam pulse.Quasifree-Scatterings and Quasifree-Reactionson Light NucleiTadahiko Yoshimura and Shigeru KakigiThe alpha cluster in a nucleus is expected to be softened compared with the alpha particle. To investigateexperimentally the softening of the alpha cluster, it is desirable to measure the ratio of the cross sectionfor the quasifree-scattering to that for the quasifree-reaction and to compare it with the correspondingratio for the free processes.Keywords: alpha cluster /Quasifree processAlpha cluster structures have been studied bothexperimentally and theoretically and alpha clustershave been recognized to exist in many nuclei. Thisfact is due to the tight binding of the alpha particlewith the binding energy of about 7 MeV/nucleon,large compared with neighboring nuclei. However,the alpha cluster in a nucleus is expected to be soft-ened slightly through interactions with other nucle-ons surrounding the alpha cluster. An interestingproblem arises: how much is the degree of the soften-ing of the cluster.The cluster structures of light nuclei have beeninvestigated experimentally through quasifreeprocesses at intermediate energies. In these process-es, the projectile interacts directly with the alphacluster in the target nucleus and the remaining partof it is playing as a spectator. In the quasifree-scatter-ing (QFS), the projectile is quasi-elastically scatteredfrom the alpha cluster. Another process is possible,that is the quasifree-reaction (QFR) [1], in which thecollision of the projectile and the alpha cluster leadsto two-body rearrangement reactions. Experimentallyit is desirable to measure the ratio of the cross sectionfor the QFS to that for the QFR in order to cancel dis-tortion effects. If the softening of the alpha cluster isassumed, the ratio for the quasifree processes isexpected to decrease compared with the correspond-ing ratio for the free processes.The experiments were performed with an 120MeV alpha-particle beam and a 296 MeV proton beamfrom the AVF cyclotron and the ring cyclotron,respectively, at RCNP of Osaka University. The tar-get nuclei were 6Li, 7Li, 9Be and 12C. Our preliminaryresults are suggesting the softening of the alpha clus-ter in 6Li. Further analyses are now in progress. Theexperiments were performed at RCNP in E46 andR04 collaborations.References1. Okihana A, Yoshimura T, Kakigi S, Ushiro K andSekioka T, RCNP Annual Report 1994, 29.

Construction of 100 MeV Electron Linac (NUCLEAR SCIENCE RESEARCH FACILITY - Particle and Photon Beams)

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Construction of 100 MeV Electron Linac (NUCLEAR SCIENCE RESEARCH FACILITY - Particle and Photon Beams)

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