-3$5&05 ࠾ࡅࡿ࢚࢟ࢧࢱ࣮㟁ᴟࡢ⾲㠃ฎ⌮ࡼࡿ ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡢᢚไࡘ࠸࡚ CONTROL OF THE MULTIPACTORING BY THE SURFACE COATING OF THE EXCITER ELECTRODES IN J-PARC MR ᒸ⏣ 㞞அ#, A)㸪እᒣ Ẏ A)㸪Schnase AlexanderB) Masashi Okada#, A), Takeshi ToyamaA), Alexander Schnase B) A) KEK J-PARC Acc. B) GSI Abstract Multiple-purpose Exciters are installed in the 30GeV main ring of J-PARC, and they are used for Bunch by Bunch Feedback, Transverse RF for slow extraction, Tune measurement and Intra-bunch feedback study. Since these Exciters are Strip line Kickers which use the parallel electrodes, a multipactoring is generated depending on the conditions of applied RF. The multipactoring gives damage to an electrode surface, and also causes the electric discharge and the beam loss due to vacuum deterioration. Then, we tried to control the multipactoring by coating of the surface of the electrodes. This time, for three kinds of treatments on the stainless steel electrodes (electrolytic polished, Diamond-Like Carbon (DLC) coated, Titanium Nitride (TiN) coated), the secondary electron yield (SEY) and the pressure rise in the vacuum chamber by multipactoring when the RF is applied were measured. 1. ࡣࡌࡵ J-PARC 30GeV ࣓ࣥࣜࣥࢢ(MR)ࡣࠊ2 ⤌ࡢ࢚ ࢟ ࢧ ࢱ ࣮ ࡀ タ ⨨ ࡉ ࢀ ࡚ ࠾ ࡾ ࠊ Bunch by Bunch Feedback ࡸ Tune ᐃ ࠊ 㐜 ࠸ ྲྀ ฟ ࡋ ࠾ ࡅ ࡿ Transverse RF Exciter ཬࡧ Intra-bunch Feedback ࡢࢫ ࢱࢹ⏝ࡉࢀ࡚࠸ࡿࠋ ࡇࢀࡽࡢ࢚࢟ࢧࢱ࣮ࡣࡑࢀࡒࢀከᑡࡢ㐪࠸ࡣ࠶ ࡿࡶࡢࡢࠊ2 ᯛࡢ㟁ᴟࢆྥ࠸ྜࢃࡏ㓄⨨ࡋࡓࢫ ࢺࣜࢵࣉࣛࣥ࢟ࢵ࣮࡛࢝ࠊࡑࢀࡒࢀࡢ㟁ᴟ㏫ ┦ࡢ㟁ᅽࢆ༳ຍࡍࡿ࡛ࣅ࣮࣒ࡢ㌶㐨ࢆㄪᩚࡍࡿࠋ ࡇࡢᵝ࡞࢚࢟ࢧࢱ࣮࡛ࡣ㟁ᴟࡢ㛫㝸 RF ࡢ᮲ ௳ࡼࡗ࡚ࡣ࣐ࣝࢳࣃࢡࢱࣜࣥࢢ࠸࠺⌧㇟ࡀⓎ⏕ ࡍࡿࠋ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡣ㟁ᴟ㛫ࡢ㟁ᅽࡀୖࡀࡽ ࡞ࡃ࡞ࡿࡢཎᅉࡸࠊᅽຊୖ᪼ࡼࡿᨺ㟁ࡸࣅ࣮࣒ ࣟࢫࡢཎᅉ࡞ࡿⅭᅇ㑊ࡍࡿࡀᮃࡲࡋ࠸ࠋ ࡑࡢⅭࠊ⌧ᅾࡢ࢚࢟ࢧࢱ࣮࡛ࡣࢳ࢙ࣥࣂ࣮ࡢእ ഃࢯࣞࣀࢻࢥࣝࢆᕳࡁ㟁ᴟ㛫ᙅ࠸☢ሙࢆ ࡌࡉࡏࡿࡇ࡛㟁Ꮚࡢ㌶㐨ࢆࡲࡆ࡚࣐ࣝࢳࣃࢡࢱࣜ ࣥࢢࢆᅇ㑊ࡋ࡚࠸ࡿࡀࠊᚤᑡࡣ࠸࠼ࣅ࣮࣒ࡢᙳ 㡪ࡀ↓࠸ࡣゝ࠸ษࢀ࡞࠸ࡸ㟁※ࡸ㓄⥺ࡢࢺࣛࣈ ࣝࣜࢫࢡࢆ⪃࠼ࡿᑗ᮶ⓗࡣࢯࣞࣀࢻࢥࣝࢆ ↓ࡃࡋࡓ࠸⪃࠼࡚࠸ࡿࠋ ᅇࠊ㟁ᴟࢆ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡢ㉳ࡁࡃ࠸⣲ ᮦ࡛ࢥ࣮ࢸࣥࢢࡍࡿ࡛ࢯࣞࣀࢻࡼࡿ☢ሙ↓ ࡋ࡛㐠㌿ฟ᮶ࡿࡼ࠺࡞ࡽ࡞࠸⪃࠼ࠊᚑ᮶ࡢ࢚ ࢟ࢧࢱ࣮࡛⏝ࡋ࡚࠸ࡿ㟁⏺◊☻ࡋࡓࢫࢸࣥࣞࢫ (SUS)ຍ࠼࡚ࠊSUS ࡢ㟁ᴟ࣐ࣝࢳࣃࢡࢱࣜࣥࢢ ࡢ㉳ࡁࡃ࠸ࡉࢀࡿ❅ࢳࢱࣥ㸦TiN)࣭ࢲࣖࣔ ࣥࢻࣛࢡ࣮࢝࣎ࣥ(DLC)࡛ࢥ࣮ࢸࣥࢢࡋࡓ≀ࢆ సᡂࡋࠊࢸࢫࢺࢆ⾜࠺ࡋࡓࠋ a) SUS b) TiN c) DLC Figure 2: Prepared electrodes Figure 1: Multiple-purpose exciters for J-PARC MR ___________________________________________ # [email protected] 2. ࣐ࣝࢳࣃࢡࢱࣜࣥࢢ ࢚࢟ࢧࢱ࣮ࡢᵝ࡞ྥ࠸ྜࡗࡓ㟁ᴟ RF 㟁ᅽ ࡀ༳ຍࡉࢀ࡚࠸ࡿ≧ἣ࠾࠸࡚ࠊࣅ࣮࣒ࡸᨺᑕ⥺ࡢ ⾪✺➼ࡢせᅉ࡛㟁ᴟ⾲㠃ࡽ 1 ḟ㟁Ꮚࡀᨺฟࡉࢀࡓ ࡍࡿࠋᨺฟࡉࢀࡓ㟁Ꮚࡣ RF 㟁ሙࡼࡾຍ㏿ࡉࢀ ᑐഃࡢ㟁ᴟ⾪✺ࡋࠊ2 ḟ㟁Ꮚࢆᨺฟࡍࡿࠋࡇࡢ RF ࡀ᭱ึࡢᨺฟࡢ㏫┦࡛࠶ࢀࡤࠊ2 ḟ㟁 Ꮚࡣࡧᑐഃࡢ㟁ᴟྥࡗ࡚ຍ㏿ࡉࢀࡿࠋࡇࡢ ࠊ⾪✺ࡋࡓ㟁Ꮚࡢᩘࡼࡾᨺฟࡉࢀࡓ㟁Ꮚᩘࡀከ࠸ 㟁Ꮚᩘࡀࢿࢬ࣑⟬ⓗቑຍࡍࡿࠋࡇࡢᵝ㟁Ꮚࡀ RF ྠᮇࡋ࡚㟁ᴟ㛫ࢆቑṪࡋ࡞ࡀࡽ⾜ࡁ࠺⌧㇟ ࢆ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡶࡋࡃࡣ 2 ࣏ࣥࢺ࣐ࣝࢳࣃ ࢡࢱࣜࣥࢢ࠸࠺ࠋ ᖹ⾜ᖹᯈ㛫ࡢ RF 㟁ሙࡼࡿ࣐ࣝࢳࣃࢡࢱࣜࣥࢢ ࡣゎᯒⓗゎࡃࡇࡀฟ᮶࡚ࠊ㟁ᴟ㛫ࡢ㊥㞳ࢆ dࠊ 㟁ᕪࢆ V ࡍࡿࠊ㟁ᴟ㛫࠶ࡿ㟁Ꮚࡢ㐠ື᪉⛬ ᘧࡣ d 2 x eV = sin(ω t + φ ) dt 2 md (1) ࡛⾲ࡍࡇࡀ࡛ࡁࡿࠋࡇࡇ࡛ࠊm ࡣ㟁Ꮚࡢ㉁㔞ࠊȰ ࡣ RF ࿘Ἴᩘࠊȭࡣึᮇ┦(0ӌȭӌȧ/2)࡛࠶ࡿࠋ t=0 ࡢ x=0ࠊdx/dt=0 ࡢ᮲௳࡛ࡇࡢᘧࢆゎࡃ้ t ࡛ࡢ㟁Ꮚࡢ⨨ࡣ x=− eV [sin(ω t + φ) − sin(φ)] + eV cos(φ) t (2) 2 ω md ωmd ࡞ࡿࠋ ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡢ㉳ࡇࡿⅭࡣࠊ㟁ሙࡀ㏫ ┦࡞ࡿ t=(2n+1)ȧ/Ȱࡢ x=d ࡞ࡽ࡞ࡃ࡚ࡣ࡞ ࡽ࡞࠸ࡢ࡛(2)ᘧࡣ d =− eV [2sin(φ) + (2n +1)π cos(φ )] (3) ω 2 md ࡞ࡾࠊRF ࡢ㟁ᅽ࿘Ἴᩘࡀࡇࡢᘧࢆ‶ࡓࡍ ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡀⓎ⏕ࡍࡿࠋࡲࡓࠊࡇࡢࡢ㟁 Ꮚࡢ࢚ࢿࣝࢠ࣮ࡣ E= 2e 2V 2 cos 2 (φ ) ω 2 md 2 (4) ࡞ࡿࠋ[1] ࢚࢟ࢧࢱ࣮ࡢ㟁ᴟ㛫㝸ࡣ 140 ੈࠊ㟁ᴟࢳ࢙ࣥ ࣂ࣮ࡢ㛫ࡢ㊥㞳ࡣ᭱▷ 26mm ࡛࠶ࡿࡢ࡛ࠊn=1 ࡋ ࡚(3)ᘧ࡛࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡢ㉳ࡁࡿ⠊ᅖࢆィ⟬ࡍ ࡿᅗ 3 ࡢᵝ࡞ࡿࠋ⣽࠸⥺ࡢ㛫ࡀ࣐ࣝࢳࣃࢡࢱࣜ ࣥࢢࡢⓎ⏕ࡍࡿ㡿ᇦ࡛ࠊኴ࠸⥺ࡀ⾪✺ࡢ㟁Ꮚࡢ࢚ ࢿࣝࢠ࣮ࡀ᭱࡞ࡿ(ȍ=0)㡿ᇦ࡛࠶ࡿࠋ 3. ḟ㟁Ꮚᨺฟ⋡ࡢ ᐃ 3.1 ḟ㟁Ꮚᨺฟ⋡ ࡇࢁ࡛ࠊඛࡢィ⟬࡛ࡣ 1 ࡘࡢ㟁Ꮚࡀ㟁ᴟ⾪✺ ࡋࡓ㝿ᨺฟࡉࢀࡿ 2 ḟ㟁Ꮚࡢᩘࢆ㸯ࡘࡋ࡚࠸ࡿ ࡀࠊᐇ㝿࠸ࡃࡘࡢ㟁Ꮚࡀᨺฟࡉࢀࡿࡣ㟁ᴟࡢ≧ ែࡸ⾪✺ࡢ㝿ࡢ㟁Ꮚࡢ࢚ࢿࣝࢠ࣮࡛␗࡞ࡿࠋヨᩱ 㟁Ꮚࡀ 1 ࡘධᑕࡋࡓ࠸ࡃࡘࡢ㟁Ꮚࡀᨺฟࡉࢀࡿ ࢆḟ㟁Ꮚᨺฟ⋡(SEY: Secondary Electron Yield) ゝ࠸ࠊᑕ㟁ὶ(Ir)/ධᑕ㟁ὶ(Ib)࡛ᐃ⩏ࡉࢀࡿࠋᐇ㝿 ࡢ ᐃ࡛ࡣୗᘧࡢᵝᑕ㟁ὶࢧࣥࣉࣝ࣍ࣝࢲ࣮ ࡽࡢࢥࣞࢡࢱ㟁ὶ(Ii)ࢆ ᐃࡋ࡚ィ⟬࡛ồࡵࡿࠋ SEY = Ir Ir − Ii (5) ඛ㏙ࡓࡼ࠺࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡣྥ࠸ ྜࡗࡓ㟁ᴟ㛫࡛㟁Ꮚࡀ⾜ࡁ᮶ࡍࡿ⌧㇟࡛࠶ࡿࡽࠊ 㟁ᴟ㛫ࢆ⾜ࡁ࠺㟁Ꮚࡀ↓ࡃ࡚ࡣⓎ⏕ࡋ࡞࠸ࠋSEY ࡀ 1 ࡼࡾࡕ࠸ࡉ࠸ሙྜࠊ㟁ᴟ㛫ࡢ㟁Ꮚࡣ㟁ᴟࡢ⾪ ✺ࡢᗘῶᑡࡋ࡚࠸ࡃࡢ࡛࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡶ ᮰ࡋ࡚࠸ࡁࠊ㏫ 1 ࡼࡾࡁ࠸ሙྜࡣ㟁Ꮚࡢᩘࡣࢿ ࢬ࣑⟬ᘧቑຍࡍࡿࡢ࡛⌧㇟ࡣ⥅⥆ཪࡣᝏࡍࡿ 㻡㻡㻜 㻡㻜㻜 Voltage (V) 㻠㻡㻜 a)System layout 㻠㻜㻜 㻟㻡㻜 㻟㻜㻜 㻞㻡㻜 㻞㻜㻜 㻞㻜 㻠㻜 㻢㻜 㻤㻜 㻝㻜㻜 Frequency (MHz) Figure 3: Multipactoring area for exciter (Solid line: between electrodes, Dashed line: between electrode and chamber.) b) DLC sample with holder c) Cover electrode Figure 4: SEY measurement system 3.2 DLC 1.3 1.25 1.2 1.15 SEY ࡢ ᐃ SEY ࡢ ᐃࡣᅗ 4 ࡢࢩࢫࢸ࣒࡛⾜ࡗࡓࠋSEY ࡣධ ᑕ࢚ࢿࣝࢠ࣮ࡼࡗ࡚ኚࢃࡿࡢ࡛ࠊ㟁Ꮚ㖠ࡢᘬฟ㟁 ᅽࢆኚ࠼࡞ࡀࡽ ᐃࢆ⾜ࡗࡓࠋ᭱ึヨᩱࢆ࣍ࣝ ࢲ࣮ྲྀࡾࡅࡓᚋࠊࡲࡎ 10-7 Pa ྎࡲ࡛┿✵ᘬ࠸ ࡓ≧ែ࡛ SEY ࢆ ᐃࡋࠊࡑࡢᚋࢳ࢙ࣥࣂ࣮ࡈ 150Υ࡛ 20 㛫࣮࣋࢟ࣥࢢࡋ࡚ࡽᗘ ᐃࢆ⾜ࡗ ࡓࠋࡇࢀࢆ 3 ✀㢮ࡢヨᩱࡑࢀࡒࢀ࡛ ᐃࡋࡓ⤖ᯝࢆ ᅗ 5 ♧ࡍࠋSEY ࡢ್ࡣ SUS>TiN>DLC ࡢ㡰࡛పࡃ ࡞ࡾࠊ࣮࣋࢟ࣥࢢࡼࡾᴫࡡ 1 ⛬ᗘపࡃ࡞ࡿࡀ ศࡿࠋࡋࡋ SEY ࡢ್ࡣᐇᶵ࡛⏝࠸ࡿ㡿ᇦࢆ୰ ᚰᗈ࠸⠊ᅖ࡛ 1 ࡼࡾࡁࡃୖᅇࡗ࡚࠸ࡿࠋ ḟ SEY ࡢ್᭱ࡀ᭱ࡶపࡗࡓ DLC ࡢヨᩱ ᑐࡋ࡚㛗㛫㟁Ꮚࣅ࣮࣒ࢆ↷ᑕࡋ࡚ scrubbing ࢆ⾜ ࠸ࠊSEY ࡀῶᑡࡍࡿࢆ ᐃࡋࡓࠋScrubbing ࡣ SEY ࡀࣆ࣮ࢡ࡞ࡿ 250eV ࡢ㟁Ꮚࣅ࣮࣒ࡢ↷ᑕࢆ⥆ ࡅࡿ࡛⾜ࡗࡓࠋࡑࡢ⤖ᯝࢆᅗ 6 ♧ࡍࠋᶓ㍈ࡣ scrubbing ࡛↷ᑕࡋࡓ㟁Ꮚࡢ⥲㔞࡛⦪㍈ࡣ SEY ࡢ᭱ ್࡛࠶ࡿࠋSEY ࡢ್ࡣᴫࡡ log ࡛ῶࡾ⥆ࡅ࡚ࡣ࠸ ࡿࡀࠊṧᛕ࡞ࡀࡽ 1 ࢆࡿࡣ࡞ࡗࡓࠋ㐣ཤࡢ㈨ ᩱ࡛ࡶ DLC ࡛ࡢ SEY ್᭱ࡣ 1.0㹼1.1 ࡛࠶ࡗࡓࡢ ࡛ࠊࡇࢀ௨ୖࡢῶᑡࡣ㞴ࡋ࠸⪃࠼ࡽࢀࡿࠋ[2] 㻞㻚㻡 㻿㼁㻿 㻿㼁㻿㼋㻮㼍㼗㼑㼐 㼀㼕㻺 㼀㼕㻺㼋㻮㼍㼗㼑㼐 㻰㻸㻯 㻰㻸㻯㼋㻮㼍㼗㼑㼐 㻞 㻿㻱㼅 1.35 SEY ⪃࠼ࡽࢀࡿࠋࡑࡢⅭࠊ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࢆⓎ⏕ࡉ ࡏ࡞࠸Ⅽࡣ㡿ᇦ࡛ SEY ࡀ 1 ௨ୗ࡞ࡿࡀ୍ ࡘࡢ┠Ᏻ⪃࠼ࡽࢀࡿࠋ ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࢆⓎ⏕ࡍࡿ᮲௳ࡢෆࠊ㟁ᴟࡢ ᵓ㐀ࡸ RF ࡢ᮲௳࡞ࡣࡑࡢ⏝┠ⓗ㛵㐃ࡍࡿࡢ ࡛ᐜ᫆ኚ᭦ࡣฟ᮶࡞࠸ࠋࡋࡓࡀࡗ࡚ࠊࡑࡢᑐ⟇ ࡋ࡚ࡣࠊḟ㟁Ꮚࡢᨺฟࢆ࠸ᢚ࠼ࡿࡀ㔜せ ࡞ࡿࠋࡑࡇ࡛ࠊ㟁ᴟྠసࡗࡓ 3 ✀㢮ࡢヨᩱࢆ ⏝࠸࡚㹑㹃㹗ࡢ ᐃࢆ⾜ࡗࡓࠋ 1.1 1.05 1 0 2 4 6 8 10 12 14 Dose (C) Figure 6: SEY of scrubbed DLC ࣜࣥࢢࡢ≧ἣࢆ ᐃࡋࡓࠋ┤᥋࣐ࣝࢳࣃࢡࢱࣜࣥࢢ ࡢᵝᏊࢆ ᐃࡍࡿࡣ㞴ࡋ࠸ࡢ࡛ࠊࡑࢀࡼࡿࢳ࢙ ࣥࣂ࣮ෆᅽຊࡢኚࢆ ᐃࡋ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࡢ ᙉࡉࡢᣦᶆࡍࡿࡇࡋࡓࠋ ᐃࡗࡓࢭࢵࢺ ࢵࣉࢆᅗ 7 ♧ࡍࠋࢳ࢙ࣥࣂ࣮ࢫࢡ࣮࣏ࣟࣝࣥ ࣉࢱ࣮࣎ศᏊ࣏ࣥࣉࡽ࡞ࡿ┿✵Ẽ⨨ࢆྲྀࡾ ࡅ࡚ࠊᑐഃ࢜ࣥࢤ࣮ࢪࢆྲྀࡾࡅ࡚ᅽຊࢆ ᐃࡍࡿᵝ࡞ࡗ࡚࠸ࡿࠋ㟁ᴟࡣᐇ㝿ࡢ㐠⏝ྠᵝ SG ࡽࡢฟຊࢆ 2 ศࡋ∦᪉ࡢ┦ࢆ㌿ࡉࡏ ࡚ 2 ྎࡢ 3kw ࡢࣥࣉධຊࠋቑᖜࡋࡓ RF ࡣ㟁ᴟ ࢆ㏻㐣ࡋ࡚ 50Ȑ4kW ࡢࢵࢸࢿ࣮ࢱ࡛྾ࡉࢀࡿࠋ ࢳ࢙ࣥࣂ࣮ྲྀࡾࡅࡓ┤ᚋࡢ㟁ᴟࡣ⾲㠃Ẽ ࡢศᏊࡀ⤖ྜࡋ࡚࠸ࡿᵝࠎ࡞≀ࡀ╔ࡋ࡚࠸ࡿ Ⅽᨺ㟁ࢆ㉳ࡇࡋࡸࡍ࠸ࠋࡑࡢⅭ ᐃࡢ๓ᅽຊࢆ ࢳ࢙ࢵࢡࡋ࡞ࡀࡽ 100MHz ࡢ RF ࢆᚎࠎ༳ຍࡋ࡚ ࣥࣉฟຊ 3kW ࡲ࡛࢚࣮ࢪࣥࢢࢆ⾜࠸ࠊᅽຊࡀᏳ ᐃࡋࡓࡇࢁ࡛ RF ࡢ࿘Ἴᩘ㟁ᅽࢆኚ࠼࡞ࡀࡽᅽ ຊࡢ ᐃࢆ⾜ࡗࡓࠋ ᐃࡣࠊRF ࡢ࿘Ἴᩘ㟁ᅽࢆ タᐃࡋ࡚༳ຍࡋࠊᅽຊࡀᏳᐃࡋࡓࡇࢁ࡛ 3 ⛊㛫ࡢ ᖹᆒࢆࡿᙧ࡛⾜ࡗࡓࠋ 㻝㻚㻡 㻝 㻜㻚㻡 㻜 㻡㻜㻜 㻝㻜㻜㻜 㻝㻡㻜㻜 㻞㻜㻜㻜 㻮㼑㼍㼙㻌㻱㼚㼑㼞㼓㼥㻌㻔㼑㼂㻕 Figure 5: SEY of SUS, TiN, and DLC ┿✵ࢸࢫࢺ 4.1 ࢸࢫࢺ࣋ࣥࢳ ᐇ㝿ࡢࢳ࢙ࣥࣂ࣮㟁ᴟྲྀࡾࡅ࡚࣐ࣝࢳࣃࢡࢱ Figure 7: Exciter RF test bench 4.2 ᐃ⤖ᯝ ᐃࡢ⤖ᯝࢆᅗ 8 ♧ࡍࠋᶓ㍈ࢆ RF ࿘Ἴᩘࠊ⦪ ㍈ࢆࣥࣉฟຊࡽィ⟬ࡋࡓ㟁ᴟࡢ㟁ᅽࡋ࡚ࠊྛ Ⅼ࡛ࡢᅽຊࢆⰍ࡛♧ࡋ࡚࠸ࡿࠋ ᐃⅬࡀṍ࡞ࡢࡣ㟁 ᅽࡢタᐃࢆ SG ฟຊ್࡛⾜ࡗࡓⅭࣥࣉࡢࢤࣥ≉ ᛶࡼࡿࢬࣞࡀ⏕ࡌ࡚ࡋࡲ࠺ࡽ࡛࠶ࡿࠋ ࢳ࢙ࣥࣂ࣮ෆࡢᅽຊࡣ 10-5Pa ௨ୗࡢᖹᖖ್ᑐࡋ ࡚ࠊSUS ࡛ࡣ᭱ 1.7*10-4 ࡲ࡛ୖ᪼ࡋࡓࡢᑐࡋ࡚ࠊ TiN ࡣ 7.5*10-5ࠊDLC ࡣ 4.5*10-5 1/2,1/3 ⛬ᗘ࡛ ࡲࡗ࡚࠸ࡿࠋࡇࡢ⤖ᯝࡣ SEY ྠࡌഴྥ࡛࠶ࡾࠊ SEY ࡢ್ࡀ࣐ࣝࢳࣃࢡࢱࣜࣥࢢᙉࡃ㛵㐃ࡋ࡚࠸ࡿ ࢆࡅ࡚࠸ࡿゝ࠼ࡿࠋ ᅽຊࡀୖ᪼ࡍࡿ㡿ᇦࡣ࡚ࡢ㟁ᴟ࡛ࡁࡃ 2 ᡤ ศࢀ࡚࠾ࡾࠊ㟁ᴟࡢ✀㢮ࡼࡽࡎࡰྠࡌᡤ ࠶ࡿࠋᅗ 3 ࡢࢢࣛࣇẚ㍑ࡍࡿࡑࢀࡒࢀ(3)ᘧ࡛ n=1 ࡋࡓሙྜࡢ㟁ᴟ㛫ཬࡧ㟁ᴟࢳ࢙ࣥࣂ࣮ෆ㠃 㛫࡛ࡢ࣐ࣝࢳࣃࢡࢱࣜࣥࢢ㡿ᇦࡼࡃ୍⮴ࡋ࡚࠸ࡿ ࡇࡀศࡿࠋࡲࡓ SEY ࡢ ᐃࡢ⤖ᯝࠊDLC ࡢሙ ྜ⾪✺ࡢ㟁Ꮚࡢ࢚ࢿࣝࢠ࣮ࡀ⣙ 200eV ௨ୖࡢ㡿ᇦ ࡛ SEY ࡀ 1 ࢆ㉸࠼ࡿࡀศࡗ࡚࠸ࡿࡢ࡛ࠊ(4)ᘧ ࡛ồࡵࡓ㟁Ꮚࡢ࢚ࢿࣝࢠ࣮ẚ㍑ࡍࡿ࣐ࣝࢳࣃࢡ ࢱࣜࣥࢢࡢ㡿ᇦࡢୗ㝈ࡼࡃ୍⮴ࡍࡿࠋ ᐃࡢ⤖ᯝࠊDLC ࢥ࣮ࢸࣥࢢࡢ㟁ᴟࡀ᭱ࡶᅽຊ ࡢୖ᪼ࡀᑡ࡞ࡃࠊ ᐃ⠊ᅖ࡛ࡢ᭱ᅽຊ 4.5*10-5Pa ࡣ MR 㐠㌿ࡢࣜࣥࢢෆࡢᅽຊྠ➼࡛࠶ࡿࠋࡋ ࡋࠊᐇ㝿㐠⏝ࡍࡿሙྜࡣࣅ࣮࣒ࡼࡾ 1 ḟ㟁Ꮚࡢ Ⓨ⏕㔞ࡀቑ࠼ࡿࡢ࡛ࡉࡽ࡞ࡿᅽຊࡢୖ᪼ࡀぢ㎸ࡲࢀ ࡿࡇࡽࢯࣞࣀࢻࢥࣝ↓ࡋ࡛ࡢ㐠⏝ࡣ㞴ࡋ࠸ ⪃࠼࡚࠸ࡿࠋ 5. ࡲࡵ ࢚࢟ࢧࢱ࣮ࡢ࣐ࣝࢳࣃࢡࢱࣜࣥࢢࢆᢚ࠼ࡿⅭࠊ 㟁ᴟࡢࢥ࣮ࢸࣥࢢ╔┠ࡋ SUS,TiN,DLC ࡢ 3 ✀ 㢮ࡢ㟁ᴟࢆసᡂࡋࡓࠊ SEY ࡢ ᐃཬࡧᐇᶵ࡛ࡢᅽຊ ᐃࢆ⾜࠸ẚ㍑ࡋࡓ ࡇࢁࠊDLC ࡛ࢥ࣮ࢸࣥࢢࡋࡓ≀ࡀ᭱ࡶࡼࡃ࣐ࣝࢳ ࣃࢡࢱࣜࣥࢢࢆᢚไ࡛ࡁࡿࡇࡀศࡗࡓࠋࡋࡋࠊ DLC ࡛ࡶ SEY ࡢ್᭱ࡀ 1 ௨ୗ࡞ࡽࡎࠊ┿✵ᗘ ࡢ ᐃ⤖ᯝ࡛ࡶ↓ࡃࡍࡇࡣฟ᮶࡚࠸࡞࠸ࠋ ᚋࠊ⾲㠃ࡢຍᕤࡸ᪂ࡓ࡞ࢥ࣮ࢸࣥࢢ⣲ᮦࡢ᳨ウ ࢆ㐍ࡵࡿணᐃ࡛࠶ࡿࠋ ࡲࡓࠊᅇࢥ࣮ࢸࣥࢢࢆࡋࡓࡢࡣ㟁ᴟᯈࡔࡅ࡛ ࠶ࡗࡓࡀࠊ㟁ᴟࢳ࢙ࣥࣂ࣮㛫࡛ࡢ࣐ࣝࢳࣃࢡࢱࣜ ࣥࢢࡶᙉࡃほ ࡉࢀࡓࡇࡽࢳ࢙ࣥࣂ࣮ෆ㠃ࡢ ࢥ࣮ࢸࣥࢢࡶ᳨ウࡋࡓ࠸ࠋ ཧ⪃ᩥ⊩ [1] Y. Kijima, "㉸ఏᑟ✵Ὕ⏝㟁ຊධຊ࢝ࣉࣛ㛵ࡍࡿ◊ ✲ ", Dr. Thesis, School of Mathematical and Physical Science, The Graduate University for Advanced Studies, 2002, http://id.nii.ac.jp/1013/00000611/ [2] M. Nishiwaki, et al., “Ⅳ⣲⣔ᮦᩱ⾲㠃ࡽࡢ 2 ḟ㟁Ꮚᨺ ฟ⾲㠃⤌ᡂ”, ┿✵ Vol. 48 (2005) No. 3 P 118-120, https://www.jstage.jst.go.jp/article/jvsj/48/3/48_3_118/_pdf ㅰ㎡ Figure 8: Exciter vacuum measurement (upper: SUS middle: TiN lower: DLC) ᮏ◊✲ࢆ㐍ࡵࡿᙜࡓࡾࠊ࢚࢟ࢧࢱࡢ〇సཬࡧࢩࢫࢸ ࣒㛵ࡋࡲࡋ࡚ከࡃࡢࢥ࣓ࣥࢺࢆ㡬ࡁࡲࡋࡓ㣕ᒣ┿⌮Ặࠊ ࢸࢫࢺ࣋ࣥࢳࡢ┿✵⨨ࡢ㈚࣭タ⨨୪ࡧࣅ࣮࣒ࣛ ࣥࡢタ⨨࡛ࡈ༠ຊ㡬ࡁࡲࡋࡓ┿✵ࢢ࣮ࣝࣉࡢᇼὒ୍㑻 Ặ࣭ᔱᮏ┿ᖾẶࠊSEY ᐃ⨨ࡢ⏝୪ࡧ ᐃ᪉ἲ ࡘ࠸࡚ࡈᣦᑟ࣭ࢥ࣓ࣥࢺࢆ㡬ࡁࡲࡋࡓஂᯇᗈ⨾Ặࡣཌ ࡃᚚ♩⏦ࡋୖࡆࡲࡍࠋ
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