[en] The discharge characteristics of a prototype ion source was investigated, which was developed and upgraded for the NBI(Neutral Beam Injection) heating system of KSTAR(Korea Superconducting Tokamak Advanced Research). The ion source was designed for the arc discharge of magnetic bucket chamber with multi-pole cusp fields. The ion source was discharged by the emission-limited mode with the control of filament heating voltage. The maximum ion density was 4 times larger than the previous discharge controlled by a space-charge-limited mode with fully heated filament. The plasma (ion) density and arc current were proportional to the filament voltage, but the discharge efficiency was inversely proportional to the operating pressure of hydrogen gas. The maximum ion density and arc current were obtained with constant arc voltage (80∼100 V), as 8 x 10¹¹ cm^-3 and 1200 A, respectively. The estimated maximum beam current was about 35 A, extracted by the accelerating voltage of 80 kV

[en] Recently, big needs on high flux 14 MeV fast neutron facility are made to test the related materials (and others) on the field of new fission reactors and fusion reactor. Also movable fast neutron generator is useful for production of radioisotopes, bomb detection, medial machine and non-destructive test. Through this project the core technologies for high flux 14 MeV fusion neutron source will be developed. In this sudy the following scopes are covered; ○ Survey of present technology on the high flux 14 MeV fusion neutron source. ○ Development of key technologies for the 14 MeV fusion neutron source. ○ Construction of heavy ion accelerator system to use heavy ion beam for material test, nano study and other new fields. The results of this study is summarized as follows; ○ Development of key technologies for 14 MeV neutron source - fabrication of prototype movable 14 MeV neutron generator - survey of fusion tritium technologies - design of fast neutron detection system ○ Construction of coolant circulation system and power distribution system for DIAC (Deajeon Ion Accelerator complex).

[en] The discharge characteristics of an MFTF-B (A Tandem Mirror Fusion Test Facility) short pulse (0.5 sec) NBI (Neutral Beam Injection) ion source was investigated with low are power (<10 kW) and filament heating power (<75 kW). The ion source will be used for the preliminary experiment of beam extraction prior to a prototype LPIS (Long Pulse Ion Source) of the KSTAR (Korea Superconducting Tokamak Advanced Research), afterwards. Optimum operating pressure in the ion source was 1 ∼ 20 x 10^-3 torr with hydrogen gas, and the plasma density was 1 ∼ 11 x 10¹⁰ cm^-3 during the discharge. The electron temperature measured by using a cylindrical Langmuir probe shown two temperature plasma by non-Maxwellian electron effect, which was originated from primary electrons emitted from the hot filament cathode. The deduced values of electron temperature with plasma potential and floating potential were close to the low electron temperature as the increase of the are power and the plasma density

[en] The paper describes: 1) Mathematical modeling of poloidal flux to define and calculate the tokamak plasma position based on a property of the plasma boundary which is always a flux surface. Controlling the plasma boundary position is therefore equivalent to equalizing the flux value on several points belonging to a curve tangent to the limiter. 2) Experimental method for determining the outmost poloidal isoflux surface by a linear combination of measurements of magnetic fluxes, fields and field gradients, without requiring knowledge of internal plasma parameters for the feedback control, i.e., with neither corrections for variation in the poloidal beta and the plasma current distribution, nor compensations for the induced currents in the vacuum vessel. Feedback control algorithm for the regulation of plasma boundary position and its electronics hardware based on the PID control theory. 3) Experimental results obtained from the RTP tokamak experiments using the present plasma control system. (Author)

[en] A large beam facility for the application of high power ion beams has been developed at the Korean Atomic Energy Research Institute (KAERI). The primary usage of this facility is to develop an 8 MW neutral beam heating system for a tokamak, but other applications using a large beam would also be possible in the near future. The facility is composed of a bucket ion source (100 kV, 55 A), related beam line components including a large vacuum chamber (3 m x 4 m x 5 m), power supplies for the ion source, control and DAS system (PXI based), beam diagnostics system (optical multichannel analyzer), and a water circulation system (2 MW) for cooling of the beam line components. The maximum beam parameters at present are a beam energy of 95 keV and a beam current of 36 A with the beam size of 13 x 45 cm². A maximum pulse length of 200 seconds can be achieved with a 1 MW beam power. The beam power with hydrogen ions will be increased up to 5.5 MW during 20 seconds. (author)

[en] DIAC (Daejeon Ion Accelerator Complex) system was developed, and operated at JAEA of Japan by KEK team with a name of TRIAC (Tokai Radioactive Ion Accelerator Complex) during 2004 to 2010. The TRIAC control system was based on LabView and had two independent control units for ion source and accelerator. To be an efficient system, it is necessary to have an integrated control capability. And the control software, which had implemented by using LabView at TRIAC, will be changed with EPICS in order to give an effective beam service to the users. In this presentation, the old TRIAC control system is described, and a new control system for DIAC is discussed. The control system of DIAC is based on TRIAC. But it is gradually improved performance using EPICS toolkits and changing some digital interface hardware of it. Details of the control system will be demonstrated during the conference

[en] KEK (High Energy Accelerator Research Organization) TRIAC (Tokai Radioactive Ion Accelerator Complex) was a radioactive isotope accelerator that can provide beams of uranium fission fragments with a maximum energy of 1.1 MeV/nucleon produced by protons of 30 MeV and 1 µA (30 W in beam power, actually deposited in the production target) from the JAEA Tandem Accelerator. The DIAC team has a plan to reassemble this device as a stable ion beam accelerator with a minimized change for the low energy beam line including the ion source and the target system. The new stable ion accelerator will be used not only for basic research but also for the application of heavy ion beams. Until recently, most of power supply, the cooling water supply and vacuum pump systems have been installed for a performance evaluation of the DIAC. The experimental results of the plasma generation in the ECR ion source are presented. We are planning to evaluate a radiation shielding analysis for an operation permit and perform the beam transport experiments from the ECR ion source to the IH linac by the end of next year

[en] ITER has been built to resolve the scientific and technological issues remained for the ignition at Cadarache in France since 2006. Korea has joined the ITER project and contributed to ITER construction and understanding of plasma physics through KSTAR (Korea Super Conducting Tokamak Advanced Research). KAERI has much experience on fusion plasmas through KT-1 development and KT-2 planning since 1983. After that we have participated the KSTAR and ITER projects in various fields. In the present paper, these activities at KAERI, especially for Fusion Nuclear Engineering Development Division were introduced. Spherical Torus has been researched as a commercial advanced fusion reactor around world and VEST(Vesatile Experiment Spherical Torus) has been built and researched at SNU(Seoul National University) since 2008. KAERI is cooperating with SNU for the high beta steady-state operation of VEST by developing 600 kW NB power and novel RF current drive concept based on the utilities and technologies accumulated through ICRF and NB development through KSTAR construction

[en] A heavy ion beam facility, which is based on the transferred heavy ion accelerator TRIAC (Tokai Radioactive Isotope Accelerator Complex) from KEK of Japan, is being constructed at KAERI with a new name DIAC (Daejeon Ion Accelerator Complex). The assembly of the main beam line of the facility, which is composed of an ECR ion source, a RFQ and IH linear accelerators, has been finished, and the important characteristics of the accelerator has been measured successfully. Radiation shielding is necessary to start beam tuning and beam acceleration. Also three target rooms are being designed to use the heavy ion beam in the various R and Ds. The present status and future plan of the heavy ion beam facility will be discussed in this present. A heavy ion beam facility is being constructed at KAERI to open the opportunities to the internal researchers on materials, bio, nano and others topics. We will try the facility be open to other researchers with a stable beam in a nearest future

[en] The observed characteristics of magnetic oscillations in L-H transition and disruption are described. Two kinds of MHD magnetic probes are used in order to cover broadband frequency range from 1.3 kHz to 300 kHz in the H-mode. Depending on the probe's position and frequency, different characteristics are observed. Precursor like oscillation in L-H transition, and the difference between sawtooth and ELM are discussed. All disruptions during the current rising phase are related with m=2 or m=3 mode. Different disruption characteristics for different operation conditions could be forund in the MHD probes