RN97 1 KAERI/CM -567'/200 1 OLMjl)00 7t+3Rl 7Hg Development of a Large Proton Accelerator for Innovative Researches sJisz4 1x- HI- CHZZY LT4-3 7H cl Development of High Power RF Source DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. KAERI/CM -567/200 1 "oLg!IIt 3 71-0&XCiil 713 Development of a Large Proton Accelerator for Innovative Researches *E!$ z+Iq-g 71 HI-= LH E i Development of High Power RF Source .. SUMMARY In accelerator field, the RF system generally means the overall system which includes all of the components to transfer the RF power generated in RF source to the accelerating cavity. Major part of the accelerator construction cost and operation cost is consumed for the RF system. In addition, the availability of the accelerator is mainly dependent on that of the RF system. KOMAC(K0rea Multipurpose Accelerator Complex) proton accelerator requires the high power RF system of which the main components are 350 MHz, 750 kW CW and 700 MHz, 1 MW CW klystrons, which makes it imperative to train the man power and to accumulate the know-how of the high power RF system. This study was performed with objective of the training of man power and accumulation of know-how of the high power RF system for the KOMAC proton accelerator. For the development of the high power RF source for CCDTL(coup1ed cavity drift tube linac), the medium power RF system using the UHF klystron for broadcasting was integrated and with this RF system we obtained the basic design data, operation experience and code-validity test data. Based on the medium power RF system experimental data, the high power RF system for CCDTL was designed and its performed was analyzed. For the fabrication of the RF system we performed the basic cathode heating experiment and precision machining of the cavity. also the prototype klystron was designed and fabricated. For the RFQ RF system, we made the specification of the Rf system and performed the conceptual design activity. - II - CONTENTS 1 Introduction ....................................................................................... 1 2. Status of the Research Activities ...................................................... 4 2.1 World-wide Research status ......................................................... 4 2.2 Domestic Research status ............................................................ 6 3. Contents and Results of the R&D Activities ....................................... 7 3.1 RF system design for the RFQ ................................................... 7 3.2 Medium power UHF klystron system .......................................... 9 3-2.1 Introduction ........................................................................ 9 3.2.2 Disassembly and Analysis of the klystron ........................... 12 3.2.3 Electromagnet design and test ............................................. 17 3.2.4 System integration ............................................................ 29 3.2.5 Experiments and results ...................................................... 32 (A) Low power DC be- extraction test ................................. 33 (B) Normal power RF extraction test ....................................... 36 3.3 KOMAC klystron ........................................................................ 40 3-3.1 Introduction ........................................................................ 40 * * * *- 3.3.2 Development Examples of MW CW klystron -..-** ** - -*a 45 (A) E9792 klystron .................................................................. 45 (B) YK1303 klystron ............................................................... 47 3.3.3 Klystron fabrication material and facilities e- -.* --e - - . *-- 49 (A) Material ........................................................................... 49 (B) fab~cationfacilities ......................................................... 54 3.3.4 Electron gun ..................................................................... 55 (A) Electron emission ............................................................ 55 (B) Cathode ........................................................................... 56 (1) B-type cathode ............................................................... 57 (2) S-type cathode ............................................................... 57 (3) M-type cathode ............................................................ 57 (4) Mm-Wypecathode ...................................................... 58 (5) other types of dispenser cathode .................................... 59 (6) fabrication process ......................................................... 60 (C) Space effect ......................................................... 61 (D) Electron gun ..................................................................... 61 (E) Current Control ............................................................... 62 (F) Electron gun design, fabrication and test ........................... 63 (1) Electron gun design ...................................................... 63 (2) Electron gun fabrication ................................................ 66 (3) Basic cathode heating experiment .................................... 68 3.3.5 RF structure ..................................................................... 72 (A) RF & beam interaction ...................................................... 72 (B) RF stn_lcture design and farication .................................... 74 (C) Cavity cold test ............................................................... 82 (1) Cold mode] cavity ......................................................... 82 (2) Measurements of the cavity parameters ........................... 85 3.3.6 Electromagnet .................................................................. 89 (A) Focusing electromagnet design .......................................... 89 (B) Focusing electromagnet fabrication .................................... 89 3.3.7 Collector ........................................................................... 94 (A) Cooling of the collector ................................................... 94 (B) Design and fabrication of the collector ................................. 96 (C) Concept of fie energy recovery .......................................... 100 3.3.8 Vacuum of the collector ...................................................... 1 06 3.3.9 Supporter structure of the klystron .................................... 108 3.3.10 Performance analysis of the klystron ................................. 1 09 4. Application of the R&D results ......................................................... 112 5. References ....................................................................................... 113 - iv - 41 1 &h A{ ................................................................................. 1 41 2 51 ~LH. 7lg7HSL SAC\ ......................................................... LO 4 yI 1EJ 391 71e 7Hsk ?ij$b ...................................................... LO 4 41 2% =+H 712 7Hg SJgk ...................................................... 6 714) &I tlCh-iH LH~9 2.4zt 3 zT 0 ................................................... 7 1% RFQE ZTjit AlhEA gyI ............................................. 7 41 23 %$+ UHF gEtOl&Eg .................................... 9 1 . A{ ................................................................................. 9 2. ~~tOlAE~ZHxjJ 9 gq ................................................ 12 3. 3x14 /gAl 2 2g ......................................................... 17 4. A~AEA +g ..................................................................... 29 5. 2Z)sjit 33 4%2 3x1 32 .......................................... 32 71. DC 9s dd .......................................... 33 Lt.. s$hocz&q JTiit 9% 2% .................................... 36 41 33 KOMACS s.+\A..EE ................................................... 40 1. A4-S ................................................................................. 40 2. MW + CW E&~tO/&~~~l7HSL 041 ................................. 45 71. E9792 sztol A E .fZ ................................................ 45 i-1 . ~~1303=ztoI hgg ............................................. 47 3. XjITk XHS s,' ghocijl ................................. 49 qs ..................................................................... 49 qxq 7&hocRl ............................................................... 54 .............................................................................. 55 fi Kt ",c p ............................................................... 55 oxDl ..................................................................... 56 (1) B-type cathode .......................................... 57 (2) S-type cathode ............................................. 57 -v- (3) M-type cathode ............................................. 57 (4) MMM-tyoe cathode ....................................... 58 (5) 7 I Et Dispenser cathode ................................. 59 (6) xjl~~~...................................................... 60 Kt . gLk XJq gilt ...................................................... 61 21 . XJqg .................................................................. 61 ut . 2 xiLTT 4 ............................................................... 62 ....................................... XJxtg +AI, q]+k 2 Ale4E!n 63 (1) XJxtg 341 ................................................ 63