Performance of 300 s-beam extraction in the KSTAR neutral beam injector

• Published in: Current applied physics Vol. 12; no. 4; pp. 1217 - 1222
• Main Authors: Chang, Doo-Hee, Jeong, Seung Ho, Kim, Tae-Seong, Lee, Kwang Won, In, Sang Ryul, Bae, Young-Soon, Kim, Jong-Su, Park, Hyun-Taek, Kim, Dong-Hyun, Yang, Hyung-Lyeol
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2012; 한국물리학회
• Subjects: Accelerators; Beam power deposition; Beamline component heat load; Beams (radiation); BTR code; calorimetry; Deposition; deuterium; Extraction; heat; Injectors; Ion beams; Ion sources; KSTAR; Long pulse ion source; Neutral beam injector; Neutral beams; water flow; Water-flow calorimetry; 물리학; Korean Peninsula; Long pulse ion source; Beam power deposition; BTR code; Water-flow calorimetry; KSTAR; Neutral beam injector; Beamline component heat load
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2012.02.063

The first neutral beam injector (NBI-1) has been developed for the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. The first long pulse ion source (LPIS-1) has been installed in the NBI-1 for an auxiliary heating and current drive of KSTAR plasmas. The performance of 300 s ion beam extraction in the LPIS-1 was investigated on the KSTAR NBI-1 system, prior to the neutral beam injection for long pulse operation. The ion source consists of a magnetic bucket plasma generator with multi-pole cusp fields and a set of prototype tetrode accelerators with circular-type apertures. The inner volume of the plasma generator and accelerator column in the LPIS-1 is approximately 123 L. The nominal operation requirements for the ion source (IS) were a 100 kV/50 A deuterium beam and a 300 s pulse length. The extraction of ion beams was initiated by the formation of arc plasmas in the LPIS-1, called an arc-beam extraction method. A stable ion beam extraction of the LPIS-1 was achieved with 80 kV/27 A and a beam perveance of 1.19 microperv for a 300 s pulse length. Beam power deposition along the NBI-1 has been measured using water-flow calorimetry (WFC), and the sum of the deposited power on the ion source and beamline components was about 93% of the drained acceleration power (Vacc•Iacc). The beam power deposition was compared to the calculated results of the beam transport with re-ionization (BTR) code.