Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
; ; *; *; *; *
JNC TN9410 99-012, 191 Pages, 1999/07
High current electron beams are required for transforming fission products by gamma-rays. Element technology to efficiently and stably accelerate the high current beam is under development for the accelerator constructed at the quantum technology development facility (QTF). The conceptual design of the accelerator was started in 1989. The test operation of the accelerator was started at a maximum permissible output of 2 kW in January 1999, after many research efforts. In the future, the performance of the accelerator is to be confirmed at a rated output of 200kW. To provide the confirmation, it is important to review and understand basic design conditions of the facility and the accelerator. For this reason, this report shows basic design conditions of the accelerator. In this report, the prerequisites and choices made in the design of the facilities are presented in a tabular form, (1)Electron gun, accelerator, beam dump, klystron, control and data acquisition system. (2)Cooling-water system, air control system and radiation control system. (3)Accelerator facility building. The report contains basic design conditions as of March 1997, when the whole facility was completed. However, certain presented designs were subsequently further modified for a part of the facilities such as the cooling-water system.
;
KEK Proceedings 98-7, p.61 - 66, 1998/11
None
Hirano, Koichiro; Emoto, Takashi; Wang, Y.; Sato, Isamu
PNC TN9410 98-068, 38 Pages, 1998/06
A high power klystron has been developed as the RF source of the high power CW electron linac (10MeV, 100mA, 1.249135GHz). CW power of 1.2MW and efficiencies over 65% at a beam voltage 85kV were the design goal. Klystrons have been manufactured untill 1997. The klystron has achieved CW RF output power of 1040kW and beam voltage of 83kV at present. The power required for future applications is about four times the maximum power with CW-mode operation to accelerate electron beam at energy of 30MeV. We have redesigned the klystron, which is able to drive peak power 4.2MW with pulse-mode operation (100
sec pulse width, 50 pps) without decreasing efficiency with CW operation. As peak power of 4.2MW at a beam voltage 147kV is required for pulse-mode operation, we have developed the electric gun, the RF window which endures peak power 4.2MW and the way of reducing apparently the output cavity Q
optimized for CW-mode operation. The output cavity Q was decreased by two obstacles located on the long window. The klystron has achieved the maximum peak power, witch was 3.55MW with efficiency of 42% at a beam voltage 147kV in present. The unstable phenomenon of the power due to backward electrons hasn't been observed in the design condition. We have succeeded in the development of the klystron so as to be able to drive both CW mode and short pulse mode. The output cavity Q made effective use of two obstacles will be optimized by simulation codes to improve efficiency.
Emoto, Takashi; Kato, Yuko*; Hirano, Koichiro; Ishikawa, Y.*; Takei, Hayanori; Nomura, Masahiro; Tani, Satoshi
PNC TN9410 98-060, 45 Pages, 1998/06
Design and construction of a high power cw (Continuous Wave) electron linac for studying feasibility of nuclear waste transmutation was started in 1989 at PNC. The PNC accelerator (10Mev, 20mA average current, 4 ms pulse width, 50 Hz repetition) is dedicated machine for development of the high current acceleration technology in future need. The computer control system is responsible for accelerator control and supporting the experiment for high power operation. The feature of the system is the measurements of accelerator status simultaneously and modularity of software and hardware for easily implemented for modification or expansion. The high speed network (SCRAMNet
15MB/s), Ethernet, and front end processors (Digital Signal Processor) were employed for the high speed data taking and control. The system was designed to be standard modules and software implemented man machine interface. Due to graphical-user-interface and object-oriented-programming, the software development environment is effortless programming and maintenance.
; *; *; *; ; *; *
PNC TN9410 98-053, 43 Pages, 1998/04
In the Power Reactor and Nuclear Fuel Development Corporation (PNC), the following are examined as part of an application technology using a high power electron linac : monochromatic gamma ray sources, free electron lasers, and intense positron sources. This report describes an adaptive estimate of a superconducting magnet in order to efficiently converge a positron beam for the development of an intense positron source. By comparing the intensity of a positron beam using a superconducting magnet with a normal conducting magnet, the intensity obtained was more than double. In addition, a small magnet was manufactured in order to examine the characteristics of the superconducting magnet as a solenoid coil. An excitement test was carried out with rated current. As a result of measuring the maximum magnetic field on the central axis, we achieved 5.6 Tesla, which was the designed value. Therefore, it was confirmed to function as a focusing device, when the superconducting magnet was used to converge the positron beam.
; ; Toyama, Shinichi; Nomura, Masahiro; ; Hirano, Koichiro
Journal of Pressure Vessel Technology, -(-), - Pages, 1998/00
None
; ; Nomura, Masahiro; Yamazaki, Yoshio; Toyama, Shinichi; Hirano, Koichiro
Proceedings of The First Asian Particle Accelerator Conference (APAC98), 0 Pages, 1998/00
None
Emoto, Takashi; Wang, Y.; Toyama, Shinichi; Nomura, Masahiro; Takei, Hayanori; Hirano, Koichiro; Yamazaki, Yoshio; Omura, Akiko; Tanimoto, Yasunori*; Tani, Satoshi
PNC TN9410 98-010, 51 Pages, 1997/12
Design and construction of a high power CW (Continuous Wave) electron linac for studying feasibility of nuclear waste transmutation was started in l989 at PNC. The transmutation by photonuclear reaction using a electron accelerator has advantages of the small production for secondary radioactive waste and broad base of accelerator technology. The PNC accelerator (10 MeV, 20 mA average current, 20% duty) has been pre-commissioned. We have been very successful to produce 3 ms pulse width electron beam with 100 mA peak and energy about 2.9 MeV at present. The rest of the accelerating section was installed by March 1997. Studies are continued towards the designed goal of 100 mA beam with 4 msec pulse width and 50 Hz pulse repetition.
; ; Toyama, Shinichi; Nomura, Masahiro; ; Hirano, Koichiro
Vol.2 p1280, 0 Pages, 1997/00
None
Hirano, Koichiro; Emoto, Takashi; Wang, Y.; Enomoto, Y; Sato, Isamu
PNC TN9410 96-071, 32 Pages, 1996/03
(Objectives) A high power klystron that generates 1.2 MW radio frequency at 1.249135GHz is required for the high power CW electron linac development. The first prototype klystron was limited RF output of 330kW with CW-mode operation and 780kW with pulse-mode operation (50 msec pulse width, 1 pps) because the window temperature reached near the critical point of destruction by thermal stress. A long pill-box type beryllia window (long pill-box window) was designed and measured using a resonant ring in high power experiment. The long pill-box window withstood the RF output of 1.7MW(CW), that has been verified by the high power experiment. (Method) The standard pill-box prototype klystron was replaced with the long pill-box window. The high power test was carried out with the converted klystron. We measured maximum CW RF output power and observed the surface temperature rise of the ceramic window in the long pill-box. (Results)The temperature increase was 36 degrees with the long pill-box window when the klystron has achieved CW RF output power of 885kW, efficiency of 46%, and beam voltage of 85kV in present. The klystron has been optimized by simulation codes to improve better efficiency. The calculation shows the maximum efficiency is 70% using optimum parameters. (Conclusions)It was shown that the long pill-box window converted klystron had maximum transmission power that was fully satisfied with specifications of the high power klystron. The klystron with these results will be manufactured and the high power test will be carried out in 1997.
; ; Toyama, Shinichi; Nomura, Masahiro; ; Hirano, Koichiro
NEA P&T Kokusai Kaigi, 0 Pages, 1996/00
None
Wang, Y.; Nomura, Masahiro; Emoto, Takashi
PNC TN9410 95-201, 16 Pages, 1995/08
It is known that a RF chopper system can remove a part of unusable beam in a RF period with penalty of emittance growth. A new idea is proposed that the chopper cavity does not add or adds very small transverse momentum to the part of the beam passing through the chopper slit. The key point of this idea is to make the fundamental and second harmonics resonate at the special mode respectively in one cavity. The design, the results of simulation by MAFIA code and prototype test are mentioned in this presentation. The test results of prototype chopper cavity show that it is not so dificult to tune two frequencies to resonate in one cavity. The measurement data of the test chopper cavity are good agreement with the calculated results. This new chopper cavity with very low emittance growth will be installed in PNC high power CW linac.
Nomura, Masahiro; Yamazaki, Yoshio; Toyama, Shinichi; Emoto, Takashi
PNC TN9410 94-190, 37 Pages, 1994/05
It is important for a high power electron linac to design the injector, because the space charge effect is large. The injector consists of a 200 kV DC gun, two magnetic lens, a RF chopper, a chopper slit, a prebuncher, a buncher and an accelerating tube 1. In order to design the injector, beam trajectories are simulated by PARMELA which is modified by PNC. In this report, three simulation results are shown. The first result is the beam trajectory from the gun to the exit of the solenoid coils. There is a thick concrete wall between the gun to the RF chopper. Low energy electrons are transported through the long solenoid coils. It can be seen from the first result that two magnetic lens between the gun and the solenoid coils can reduce the emittance growth. The second result is for the chopper part. The novel chopper system is designed to reduce the emittance growth. The last result is the beam trajectory from gun to chopper slit. From those simulation results, it can be seen that the emittance at the end of the injector is reduced to about 10 
mm mrad by the novel chopper system.
Emoto, Takashi
PNC TN9410 93-148, 21 Pages, 1993/06
The instrumentation of and the control system for the PNC 10MeV CW electron linac are described. A new concept of parallel input/output processing for the linac has been introduced. It is based on a substantial number of input/output processors(IOP) using beam control and diagnostics. The flexibility and simplicity of hardware/software are significant advantages with this scheme.
Toyama, Shinichi; Wang, Y. L.; Emoto, Takashi; Nomura, Masahiro; Takahashi, Nobutomo; Oshita, Hironori; Hirano, Koichiro; Himeno, Yoshiaki
Proceedings of 1993 Particle Accelerator Conference (PAC 1993), p.546 - 548, 1993/05
Times Cited Count：0 Percentile：0.04(Instruments & Instrumentation)None
Toyama, Shinichi; ; Hirano, Koichiro; Oshita, Hironori; Nomura, Masahiro; ; Takahashi, Nobutomo
PNC TN9430 93-002, 43 Pages, 1993/01
[Background] Development of a CW electron linac which can accelerate a few order higher beam current is under development in PNC. So far, design of main components: accelerating tube and a klystron has been carried out. This time high power RF experiment of the developed components was carried out without electron beam. [Objective] An experiment with high power RF was carrying out in order to validate the design of the components. In regard to ceramic windows for the klystron, improvement of its design was found necessary in accordance with the experiment in last year. Therefore the design was improved, and high power RF experiment was carried out for test window manufactured based on the improved design. [Method] The test system for a accelerating tube and klystron windows was constructed and high power RF experiment was carried out using this system where the trial klystron was used as high power RF source. The experiment was carried out in National Laboratory for High Energy Physics (KEK) in Tsukuba where the high voltage DC power supply is available. [Result] The traveling wave resonant ring was successfully driven with 800 kW RF power which is around the final goal in the case of no beam loading. The unexpected thermal dissipation was observed at the phase shifter of the resonant ring because of its high RF attenuation. The klystron windows that have the optimized design dimension could transmit the 1.7 MW RF power which is strongest over the world in L-band. [Conclusion] The validity of the design of traveling wave resonant ring and klystron windows was demonstrated by high power RF loading experiment. But, the phase shifter needs more improvement to make it possible to use under hundreds of high power RF.
Toyama, Shinichi; Emoto, Takashi; Himeno, Yoshiaki; Hirano, Koichiro; Konashi, Kenji; Oshita, Hironori; Sasao, Nobuyuki; Takahashi, Nobutomo; Wang, Y. L.; 12 of others*
Proceedings of 3rd European Particle Accelerator Conference (EPAC '92), p.533 - 535, 1992/04
None
