ከࢳࣕࣥࢿࣝ QCM ࢆ⏝࠸ࡓࢹࣇࣞࣥࢩ࣭ࣕࣝࢫࣃࢵࢱࣜࣥࢢࡢィ すᮧ ኴ୍㑻
㸨㸪ᑠἨ ᏹஅ
㸨㸨㸪ᅧ୰ ᆒ
㸨㸨㸪ᒣᴟ ⰾᶞ
㸨Abstract㸸
Key words㸸
ࡣࡌࡵ
Shizuoka University
ከࢳࣕࣥࢿࣝ QCM ࢆ⏝࠸ࡓࢹࣇࣞࣥࢩ࣭ࣕࣝࢫࣃࢵࢱࣜࣥࢢࡢィ すᮧ ኴ୍㑻
㸨㸪ᑠἨ ᏹஅ
㸨㸨㸪ᅧ୰ ᆒ
㸨㸨㸪ᒣᴟ ⰾᶞ
㸨Measurements of Differential Sputtering Yields Using Multi Channel Quartz Crystal Microbalance
By
Taichiro NISHIMURA*, Hiroyuki KOIZUMI **, Hitoshi KUNINAKA ** and Yoshiki Yamagiwa
Abstract㸸Life time assessment of an ion engine needs sputtering characteristics on grid material. Sputter yield on molybdenum due to xenon ion impingement was measured by a conventional weight loss technique using a miniature ion engine. New multiple Quartz crystal Microbalance (QCM) system, positioned in hemispherical on the target plane, revealed the differential sputtering yields. The resulted sputtering yields agreed with the data given by the other conventional methods.
Key words㸸Ion engine, Ion optics, Grid life time, Sputtering, QCM
1. ࡣࡌࡵ
࢜ࣥࢫࣛࢫࢱࡢᑑࢆไ㝈ࡍࡿせ⣲ࡣ࢜ࣥຍ㏿ࢢࣜࢵࢻࡢᦆ⪖ࡀ࠶ࡿ㸬ࡑࡢ⪏ஂㄆᐃࡣᐇ㛫࡛ࡢᩘ
㛫⣭ࡢ⪏ஂヨ㦂ࢆ⾜࡞࠺⌧≧ࡀ࠶ࡾ㸪ᚋࡢ⪏ஂᛶㄆᐃࡣᩘ༓㛫⣭ࡢᐇ㛫⪏ஂヨ㦂ᩘ್ᑑண
ࢆྜࢃࡏࡓ⪏ஂㄆᐃ᪉ᘧࡀᥦࡉࢀ࡚࠸ࡿ㸬ࡋࡋ࡞ࡀࡽ㸪ࡇࡢࡼ࠺࡞ࢢࣜࢵࢻ⪏ஂᛶホ౯⏝ᩘ್ゎᯒࢶ࣮ࣝࡢ 㛤Ⓨ࡛ࡣ㸪㐺ṇ࡞≀⌮ࣔࢹࣝཬࡧࣝࢦࣜࢬ࣒ࡢ⏝ࡸィ⟬ࡢ㧗㏿࡞㸪ࢥ࣮ࢻ㛤Ⓨୖࡢᵝࠎ࡞ၥ㢟ࢆඞ᭹ࡍ
ࡿᚲせᛶࡀ࠶ࡿࡢຍ࠼㸪ྛ✀ᐇ㦂ࢹ࣮ࢱྲྀᚓࡶ㔜せ࡞ࡿ㸬≉㸪ࢫࣃࢵࢱࣜࣥࢢ≉ᛶ㛵ࡍࡿሗࡣࢢࣜࢵ
ࢻຎホ౯ࡣ㔜せ࡞≀ᛶ್࡛࠶ࡾ㸪༢ࢢࣜࢵࢻࡀ๐ࢀࡿ㔞ࡔࡅ࡛࡞ࡃ㸪ࢫࣃࢵࢱࣜࣥࢢࡼࡗ࡚ᨺฟࡉࢀࡓ ࢢࣜࢵࢻᮦᩱཎᏊࡢᑕฟ᪉ྥ࠾ࡼࡧ╔⌧㇟ࡶ⪃៖ࡍࡿᚲせࡀ࠶ࡿ㸬
ᮏ◊✲࡛ࡣࢫࣃࢵࢱࣜࣥࢢ≉ᛶゎ᫂ࡢࡓࡵ㸪ࢫࣃࢵࢱ⋡ཬࡧᚤศࢫࣃࢵࢱ⋡ࡢᐇ㦂ⓗ ᐃࢆ⾜ࡗࡓ㸬ࢫࣃࢵ
ࢱ⋡ࡣ୍ධᑕ⢏Ꮚ࠶ࡓࡾࡢࢫࣃࢵࢱཎᏊᩘ࡛࠶ࡾweight loss ἲࡼࡾồࡵࡽࢀࡓ㸬ࡇࢀࡣ㸪ᐇ㦂୰↷ᑕࡋࡓ
࢜ࣥ⢏Ꮚᩘ࠾ࡼࡧᐇ㦂๓ᚋࡢ⿕↷ᑕᮦࡢ㉁㔞ᕪࡽᚓࡽࢀࡓࢫࣃࢵࢱ⢏Ꮚᩘࡼࡾ⟬ฟࡍࡿ᪉ἲ࡛࠶ࡾ㸪ࡇࢀࡲ
࡛ከࡃࡢ ᐃࡀ࠶ࡿ㸬୍᪉࡛㸪ᚤศࢫࣃࢵࢱ⋡ࡣ࠶ࡿ᪉ྥࡢ༢❧యゅ࠶ࡓࡾࡢᑕฟᩘ࡛࠶ࡾ㸪╔
⌧㇟ࢆ⪃៖ࡍࡿୖ࡛ᚲせྍḞ࡞ࣃ࣓࣮ࣛࢱ࡛࠶ࡿ㸬ከࡃࡢ ᐃᡭἲࡣ㸪㸯ࡘࡢỈᬗືᏊᚤᑠኳ⛗㸦QCM㸧
ࢆᤄᘬࡍࡿࡇ࡛᪉ྥࡢᚤศࢫࣃࢵࢱ⋡ࢆྲྀᚓࡍࡿ᪉ἲ࡛࠶ࡿ㸬ࡋࡋ࡞ࡀࡽ㸪㸯ࡘࡢQCMࢆᤄᘬࡍࡿᐇ㦂
࡛ࡣ㸪ᐇ㦂㛫ࡢ㛗ᮇࡸࡑࢀక࠺⎔ቃኚࡼࡿㄗᕪ㸪ࡉࡽࡣᤄᘬ⨨ࡸQCMタഛࡢࢥࢫࢺ㠃࠸ࡗࡓ ᠱᛕ㡯ࡀ࠶ࡿ㸬ࡑࡇ࡛㸪ᮏ◊✲࡛ࡣᏳ౯࡞QCMࢆ」ᩘྠ⏝࠸ࡿࡇࡼࡾ㸪᪉ྥࡢᚤศࢫࣃࢵࢱ⋡ࢆ
ྠྲྀᚓࡍࡿᡭἲࢆᥦࡋࡓ㸬ࡇࡢᡭἲࢆ⏝࠸ࡿࡇࡼࡾ㸪ᐇ㦂㛫ࡢ▷⦰ࡸ ᐃࡢྠᛶࡀᮇᚅ࡛ࡁࡿࠋ
2
᭱⤊ⓗࡣC-C」ྜᮦ࠾ࡅࡿࢫࣃࢵࢱ≉ᛶྲྀᚓࢆ┠ᶆࡋ࡚࠸ࡿࡀ㸪ᅇࡢᐇ㦂࠾࠸࡚ࡣ㸪ᮏᡭἲ㸸ከࢳࣕ
ࣥࢿࣝ㹏㹁㹋ࡼࡿ ᐃࢩࢫࢸ࣒㸦Multiple QCM System㸧ࡢጇᙜᛶࢆホ౯ࡍࡿࡓࡵ㸪ẚ㍑ࢹ࣮ࢱࡢከ࠸ࣔࣜ
ࣈࢹࣥࢆࢱ࣮ࢤࢵࢺᮦᩱࡋ࡚⏝࠸᳨࡚ドᐇ㦂ࢆ⾜ࡗࡓ㸬 2. ᐇ㦂᪉ἲ
2.1. ᐇ㦂⨨
ᮏᐇ㦂⏝࠸ࡓᐇ㦂⨨ࢆᅗ㸯♧ࡍ㸬࢜ࣥ※ࡣᑠᆺ࣐ࢡࣟἼᨺ㟁ᘧ࢚࢜ࣥࣥࢪࣥ㸦ȝ1㸧[1]㸪ࣅ࣮࣒
※ࡣ࢟ࢭࣀࣥ࢞ࢫࢆ⏝࠸㸪ࢱ࣮ࢤࢵࢺࡣࣔࣜࣈࢹࣥᯈࢆ⏝ࡋࡓ㸬ࢱ࣮ࢤࢵࢺᯈࡽࢫࣃࢵࢱࡉࢀࡓ⢏Ꮚࡣ 㸵ࡘࡢỈᬗືᏊᚤᑠኳ⛗ࡽ࡞ࡿ ᐃ⨨㸦Multiple QCM System㸧ࡼࡾ ᐃࡉࢀࡿ㸬ࡲࡓ㸪ᮏᐇ㦂ࡣ┿✵ᵴ 㸦┤ᚄ1 m ×㛗ࡉ1.4 m 㸧ෆ࡛ࢱ࣮࣎ศᏊ࣏ࣥࣉ࣮ࣟࢱ࣮࣏ࣜࣥࣉࡼࡾ1×10-3 㹼 7×10-3 Pa ࡢ┿✵ᗘ࡚
⾜ࢃࢀࡓ㸬⨨ࡢヲ⣽ࡣᚋㄝ᫂ࡍࡿ㸬
Ion Source
Target
QCM Ion
Beam
Turbo-molecular Pump
Rotary Pump Ion Gauge Xe Gas Flow meter
䃐
Ion Source
Target
QCM Ion
Beam
Turbo-molecular Pump
Rotary Pump Ion Gauge Xe Gas Flow meter
䃐
(a) ᐇ㦂⨨యࡢᶍᘧᅗ (b) ᐇ㦂⨨ᅗ
ᅗ 1 ᐇ㦂⨨
2.1.1. ࢜ࣥ※ཬࡧᶆⓗᮦᩱ
࢜ࣥ※⏝࠸ࡿȝ㸯ࡣᨺ㟁ᐊ┤ᚄ 20 mm ࡢᑠᆺ࢚࢜ࣥࣥࢪ࡛ࣥ࠶ࡿ㸬࢜ࣥࣅ࣮࣒ࡢ୰ࡣȝ㸯ୗὶ 10 mm タ⨨ࡉࢀࡓࢱࣥࢢࢫࢸࣥࣇ࣓ࣛࣥࢺࡼࡾ⾜࡞ࡗࡓ㸬ࢱ࣮ࢤࢵࢺᮦᩱ࡞ࡿࣔࣜࣈࢹࣥᯈ㸦ij40 mm㸪 ཌࡉ 1 mm㸧ࡣȝ㸯ୗὶ 100 mm 㓄⨨ࡉࢀ㸪࢜ࣥࣅ࣮࣒ࡣࢱ࣮ࢤࢵࢺ⾲㠃ᑐࡋ࡚ᆶ┤ධᑕࡋࡓ㸬ࡲࡓ㸪 ࢱ࣮ࢤࢵࢺᖹ㠃㸦ȝ㸯ୗὶ 100 mm㸧࡛ࡢࣅ࣮࣒ࣉࣟࣇࣝࡣ㸪ࣛࣥࢢ࣑ࣗࣉ࣮ࣟࣈ㸦ij3 mm㸪W㸧࡚㸪
ࣅ࣮࣒୰ᚰ㧗ࡉ㸪୰ᚰࡽ༙ᚄ 100 mm ࡢ⠊ᅖࢆᤄᘬࡍࡿࡇ࡛ྲྀᚓࡋࡓ㸦ᅗ㸰㸧㸬ᅗ㸱ࡣ 1000 eV ࡛ࡢᆺ
ⓗ࡞࢜ࣥࣅ࣮࣒㟁ὶᐦᗘศᕸࢆ♧ࡍ㸦ࡇࡢࡁ㸪ὶ㔞 0.4 sccm㸪࣐ࢡࣟἼᢞධ㟁ຊ 10 W㸪ࢫࢡ࣮ࣜࣥ㟁ᴟ
1000 V㸪ࢡࢭࣝ㟁ᴟ -300 V㸪ࣅ࣮࣒㟁ὶ 5 mA㸧㸬␗࡞ࡿࣅ࣮࣒࢚ࢿࣝࢠ࣮࠾࠸࡚ࡶࡰྠᵝ࡞ศᕸᙧ≧ࢆᚓ
ࡓ㸬
54 宇宙航空研究開発機構研究開発報告 JAXA–RR–09–004
Ion Beam
Probe Ion Beam
cylinder
Probe path Ion
Beam
Probe Ion Beam
cylinder
Probe path
ᅗ 2 ࣉ࣮ࣟࣈィ ᡭἲ
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14
-10 -5 0 5 10
Probe Position [cm]
Current Density [mA/cm2]
ᅗ 3 㟁ὶᐦᗘศᕸ㸦1000 eV㸪ȣ㸯ୗὶ100 mm㸧
2.1.2. ᐃ⣔
ᮏᐇ㦂 ᐃ⨨ࡋ࡚⏝࠸ࡓỈᬗືᏊᚤᑠኳ⛗㸦QCM㸧ࢆᅗ4♧ࡍ㸬QCMࡣỈᬗືᏊࡢ㟁ᴟ╔
ࡍࡿ≀㉁ࡢ㉁㔞ᛂࡌ࡚ඹ࿘Ἴᩘࡀኚື㸦ῶᑡ㸧ࡍࡿᛶ㉁ࢆ⏝ࡋ㸪Ỉᬗ╔ࡋࡓ≀㉁㉁㔞ࢆィ ࡍࡿࢭࣥࢧ
࣮࡛࠶ࡿ㸬ᅇ⏝࠸ࡿQCM࡛ࡣ௨ୗࡢ⟬ᘧ[2]ࡼࡾ㸪 ᐃࡋࡓQCM㟁ᴟࡢ࿘Ἴᩘኚ㔞 [Hz/min] ࢆࢫࣃ
ࢵࢱ≀╔㔞 [ng/min] ⟬ࡍࡿࡇ࡛༢㛫࠶ࡓࡾࡢQCM㟁ᴟࡢ╔⋡ࡀồࡵࡽࢀࡿ㸬 P m
r
F F Δ
×
− ×
=
Δ
π
2μ
2
8 0
(1)
ࡇࡇ࡛㸪F0ࡣQCMࢭࣥࢧ࣮ࡢ࿘Ἴᩘ㸪rࡣQCM㟁ᴟ┤ᚄ㸦㸻5[mm]㸧࡛࠶ࡾ㸪
μ
࠾ࡼࡧPࡘ࠸࡚ࡣࡑࢀࡒࢀỈᬗືᏊࡢࡏࢇ᩿ᛂຊẚ㔜࡛࠶ࡾ㸪ᘧ㸦㸯㸧ࡽQCM㟁ᴟࡣ࿘Ἴᩘኚ㔞1 [Hz] ࠶ࡓࡾ1.07 [ng]
╔ࡋ࡚࠸ࡿ⟬࡞ࡿ㸬
(a) QCM㟁ᴟ (b) QCMయᅗ ᅗ 4 ᮏᐇ㦂⏝࠸ࡓQCMᅗ
ᮏᐇ㦂࡚᪂ࡓస〇ࡋࡓMultiple QCM System ࡣ㸵ࡘࡢQCMࡽᵓᡂࡉࢀ㸪ᅗ㸯♧ࡍࡼ࠺ࢱ࣮ࢤࢵ
ࢺ୰ᚰࡽ༙ᚄ100 mm ࡢᘼୖࢆࢱ࣮ࢤࢵࢺ⾲㠃ᆶ┤ᑐࡋ࡚࡞ࡍゅȘ㸦㸻᳨ฟゅ㸧ࡀࡑࢀࡒࢀ 20 ~ 80 deg ࡞ࡿࡼ࠺ࡑࢀࡒࢀタ⨨ࡉࢀࡿ㸦ᅗ5(a)㸧㸬ඛ❧ࡗ࡚⾜ࡗࡓணഛᐇ㦂ࡽ㸪ᮏᐇ㦂⏝࠸ࡿQCMࡢࡲࢃ
ࡾ㟼㟁࢝ࣂ࣮ࢆタ⨨ࡍࡿᚲせࡀ࠶ࡿࡇࡀࢃࡗࡓ㸬ࡇࢀࡣ⇕ⓗཪࡣ㟁Ẽⓗ࡞ᙳ㡪ࢆ㐽᩿ࡍࡿᙺࢆࡶࡘ㸬ࡇ ࡢ㟼㟁࢝ࣂ࣮ࡣ㔜ᵓ㐀࡞ࡗ࡚࠾࠸㸪ෆഃࡢ࢝ࣂ࣮ࡣࡑࢀࡒࢀࡢQCMࢆそ࠸㸦ᅗ5(b)㸧㸪እഃࡢ࢝ࣂ࣮ࡣQCM ࢩࢫࢸ࣒యࢆそࡗ࡚࠸ࡿ㸦ᅗ5(c)㸧㸬࡞࠾㸪୧᪉ࡢ࢝ࣂ࣮ࡣQCM㟁ᴟṇ㠃ࡢࡳȭ4 mm ࡢ✰ࡀ㛤࠸࡚࠸ࡿ㸬
ࡇࢀࡽࡢ✰ࡣࢱ࣮ࢤࢵࢺࡽࢫࣃࢵࢱࡉࢀࡓ≀㉁ࡢᨺฟ᪉ྥࢆ㝈ᐃࡉࡏࡿࡓࡵࡢ㸪ࢥ࣓࣮ࣜࢱࡋ࡚ࡢᙺࡶే
ࡏᣢࡘ㸬
QCM Inner cover Outer cover
QCM Inner cover Outer cover
(a) QCM (b) ෆഃ࢝ࣂ࣮ (c) እഃ࢝ࣂ࣮
ᅗ 5 QCMཬࡧ㟼㟁ࢩ࣮ࣝࢻࡢᵓ㐀
2.2. ᐇ㦂ᡭ㡰
ࡇࡇ࡛ࡣ㸪ᮏ◊✲࠾࠸࡚⾜ࡗࡓ㸰✀㢮ࡢᐇ㦂ࡘ࠸࡚ࡢㄝ᫂ࢆ⾜࠺㸬ࡲࡎ㸪Weight Loss ἲࢆ⏝࠸ࡓࢫࣃࢵ
ࢱ⋡ ᐃࡘ࠸࡚ㄝ᫂ࡋࡓ㸪Multiple QCM System ࢆ⏝࠸ࡓᚤศࢫࣃࢵࢱ⋡ ᐃࡘ࠸࡚㏙ࡿ㸬࢟ࢭࣀࣥࣅ
࣮࣒ࡣࣔࣜࣈࢹࣥࢱ࣮ࢤࢵࢺᑐࡋ࡚ᆶ┤ධᑕࡋ㸪ࣅ࣮࣒࢚ࢿࣝࢠ࣮ࡣ 500㸪750㸪1000㸪1500 eV ኚ࠼࡚
ࡑࢀࡒࢀࡢᐇ㦂ࢆ⾜ࡗࡓ㸬ࡲࡓ㸪ᐇ㦂୰ࡣ㸪ࢱ࣮ࢤࢵࢺධᑕࡉࢀࡿ㟁ὶ㔞㸪ࢱ࣮ࢤࢵࢺ ᗘཬࡧQCM ᗘ
ࢆ ᐃࡋ࡚࠸ࡿ㸬ࡇࡇ࡛㸪ࡇࢀࡽࡢᐇ㦂࡚ᅛᐃࡋࡓືస᮲௳ࢆ⾲㸯♧ࡍ㸬
⾲ 1 ᅛᐃືస᮲௳
᥎㐍㸦ࣅ࣮࣒※㸧 Xe ᥎㐍ὶ㔞 0.4sccm
ࢱ࣮ࢤࢵࢺᮦᩱ Mo
ࢱ࣮ࢤࢵࢺ㟁ᅽ -30V
2.2.1. ࢫࣃࢵࢱ⋡ ᐃ
ࢫࣃࢵࢱ⋡ࡣᐇ㦂๓ᚋࡢࢱ࣮ࢤࢵࢺ㉁㔞ᕪཬࡧᐇ㦂୰ࡢ࢜ࣥ↷ᑕ㔞ࡼࡾồࡵࡽࢀࡿ㸬ྛᐇ㦂࠾࠸࡚㸪↷ᑕ
㛫ࡣ㸯㛫ᅛᐃࡋ࡚⾜ࡗࡓ㸬ᐇ㦂୰ࢫࣃࢵࢱࡉࢀࡓཎᏊᩘ㸦Na㸧ࢱ࣮ࢤࢵࢺධᑕࡋࡓ࢜ࣥᩘ㸦Ni㸧
ࡼࡾ௨ୗࡢᘧࢆ⏝࠸࡚ࢫࣃࢵࢱ⋡㸦Y㸧 [atoms/ion] ࡣ⟬ฟࡉࢀࡿ㸬
e I M
M M N Y N
T Mo
b a
i a
) 1 ( +
γ
−
=
= (2)
ࡇࡇ࡛㸪MaཬࡧMbࡣᐇ㦂๓ᚋࡢࢱ࣮ࢤࢵࢺ㉁㔞ࢆ♧ࡋ㸪ITࡣᐇ㦂୰ࡢࢱ࣮ࢤࢵࢺ㟁ὶࢆ♧ࡋ࡚࠸ࡿ㸬ࢫ
ࣃࢵࢱཎᏊᩘࡣ㟁Ꮚኳ⛗ࡼࡾ ᐃࡋࡓᐇ㦂๓ᚋࡢࢱ࣮ࢤࢵࢺࡢ㉁㔞ᕪࢆཎᏊ㉁㔞 MMo࡛㝖ࡍࡇࡼࡾ⟬ฟ ࡋࡓ㸬ࡲࡓ㸪ࢱ࣮ࢤࢵࢺࡢධᑕ࢜ࣥᩘࡣࢱ࣮ࢤࢵࢺ㟁ὶࡽ⟬ฟࡋࡓ㸦࢟ࢭࣀࣥ࢜ࣥࡣࡍ࡚㸯౯࡛࠶ࡿ
56 宇宙航空研究開発機構研究開発報告 JAXA–RR–09–004
௬ᐃ㸧㸬࡞࠾㸪Ȗࡣḟ㟁Ꮚᨺฟಀᩘ࡛࠶ࡿࡀᅇࡢ⟬ฟ࠾࠸࡚ࡣ⪃៖ࡋ࡚࠸࡞࠸㸬
2.2.2. ᚤศࢫࣃࢵࢱ⋡ ᐃ
ࢫࣃࢵࢱ≀ࡢᨺฟ᪉ྥࢆ♧ࡍᚤศࢫࣃࢵࢱ⋡ࡣQCMࢆ⏝࠸ࡓࣜࣝࢱ࣒ィ ࡼࡾồࡵࡽࢀࡿ㸬༢㛫
࠶ࡓࡾ᳨ฟゅĮ ᪉ྥᨺฟࡋࡓࢫࣃࢵࢱཎᏊᩘ㸦n(Į)㸧ࡑࡢ㛫ࢱ࣮ࢤࢵࢺධᑕࡋࡓ࢜ࣥᩘ㸦ni㸧ཬ ࡧQCMࡢ❧యゅ㸦sr㸧ࡼࡾ௨ୗࡢᘧࢆ⏝࠸࡚ᚤศࢫࣃࢵࢱ⋡㸦y(Į)㸧 [atoms/ion/steradian] ࡣ⟬ฟࡉࢀࡿ㸬
) 2
1 (
) ( )
) (
( L
S e
i Ȗ M
Į m n sr
Į Į n y
i Mo
i = +
= (3)
ࡇࡇ࡛㸪SࡣQCM㟁ᴟࡢ㠃✚㸪Lࡣࢱ࣮ࢤࢵࢺ୰ᚰࡽQCM㟁ᴟࡲ࡛ࡢ㊥㞳ࢆ♧ࡋ㸪iiࡣࢱ࣮ࢤࢵࢺ㟁ὶ
ࢆ♧ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪᳨ฟゅ Į = 20 ~ 80 deg ⨨ࡍࡿ㸵ࡘࡢQCM㟁ᴟࡢࡑࢀࡒࢀࡢ࿘Ἴᩘኚື⋡ࢆ๓㏙
ࡢᘧ㸦㸯㸧ࡼࡾ╔⋡⟬ࡍࡿࡇࡼࡾ㸪༢㛫࠶ࡓࡾࡢĮ᪉ྥࡢࢫࣃࢵࢱ㉁㔞 m(Į)ࡀồࡵࡽࢀ
ࡿ㸬࡞࠾ඛ⛬ྠᵝ㸪ḟ㟁Ꮚᨺฟಀᩘࡣ⪃៖ࡋ࡚࠾ࡽࡎ㸪࢟ࢭࣀࣥ࢜ࣥࡣࡍ࡚㸯౯࡛࠶ࡿ௬ᐃࡋ࡚࠸ࡿ㸬 3. ᐇ㦂⤖ᯝ࣭⪃ᐹ
3.1. ࢫࣃࢵࢱ⋡ ᐃ⤖ᯝ
ྛࣅ࣮࣒࢚ࢿࣝࢠ࣮࠾࠸࡚㸪㸯㛫↷ᑕᐇ㦂๓ᚋࡢ㉁㔞ᕪࡼࡾࣔࣜࣈࢹࣥࡢ࢟ࢭࣀࣥࡼࡿࢫࣃࢵࢱ㔞ࢆぢ
✚ࡶࡗ࡚ᚓࡽࢀࡓࢫࣃࢵࢱ⋡ࢆẚ㍑ࡋࡓࡢᩥ⊩್[3][4][5][6]ඹᅗ㸴♧ࡍ㸬
0.1 1 10
1.E+02 1.E+03 1.E+04
Ion Energy [eV]
Sputter Yields [atoms/ion]
Present Study Zoerb Tartz Kolasinski
Yamamura&Tawara
ᅗ 6 ࢫࣃࢵࢱ⋡
ᅗ㸴ࡢࢹ࣮ࢱࢆẚࡿ㸪ᮏᐇ㦂࡚ᚓࡽࢀࡓࢫࣃࢵࢱ⋡ࡣࡢᐇ㦂⤖ᯝཬࡧᒣᮧࣔࢹ࡛ࣝࡢࢫࣃࢵࢱ⋡ࡼࡾࡶ
ᑡࡋᑠࡉ࠸್ࢆ♧ࡋ࡚࠸ࡿഴྥࡀ࠶ࡿࡀ㸪ศᕸࡣࡼࡃఝ࡚࠸ࡿࡇࡀࢃࡿ㸬ࡇࡇ࡛㸪ࢫࣃࢵࢱ⋡ࡀᑠࡉࡃ࡞ࡗ ࡓせᅉࡋ࡚ࡣ㸪๓㏙ࡢᘧ㸦㸰㸧࠾࠸࡚㸪ḟ㟁Ꮚᨺฟࡢᙳ㡪ࢆ⪃៖ࡋ࡚࠸࡞࠸ࡇࡀᣲࡆࡽࢀࡿ㸬ḟ㟁Ꮚ ᨺฟࢆ⪃៖ࡋ࡚࠸࡞࠸⌧≧࡛ࡣ㸪ࢱ࣮ࢤࢵࢺࡢὶධ࢜ࣥᩘࢆ㐣ぢ✚ࡶࡗ࡚࠸ࡿࡇ࡞ࡿ㸬ࡋࡓࡀࡗ࡚㸪
ḟ㟁Ꮚᨺฟࢆ⪃៖ࡍࡿࢫࣃࢵࢱ⋡ࡣᅇࡢぢ✚ࡶࡾࡼࡾࡶࡁࡃ࡞ࡿ㸬
3.2. ᚤศࢫࣃࢵࢱ⋡ ᐃ
Multiple QCM System ࡼࡿࣜࣝࢱ࣒ィ ࡼࡾᚓࡽࢀࡓᚤศࢫࣃࢵࢱ⋡ࢆᅗ㸵♧ࡋ㸪ࣅ࣮࣒࢚ࢿࣝ
ࢠ࣮ࡀ 500 eV ࡢࡁࡢᚤศࢫࣃࢵࢱ⋡ࢆࡢᩥ⊩್[3][7]ẚ㍑ࡋࡓ⤖ᯝࢆᅗ㸶♧ࡍ㸬ࡲࡓ㸪ࡕࡽࡢᅗࡶᴟ
ᗙᶆ࡛⾲♧ࡋ࡚࠾ࡾ㸪⥳ࡢ▮༳ࡢྥࡁࡽ࢜ࣥࣅ࣮࣒ࡀධᑕࡋࡓࡁࡢࢱ࣮ࢤࢵࢺ㠃ᑐࡋ࡚ᆶ┤ࡽQCM
᳨ฟゅȘ᪉ྥࡢᚤศࢫࣃࢵࢱ⋡ࢆ♧ࡋ࡚࠸ࡿ㸬
0 0.1 0.2 0.3
0 0.1 0.2 0.3
Diff. Sputter Yield [atoms/ion/steradian]
1500eV 1000eV 750eV 500eV
0 0.1 0.2
0 0.1 0.2
Diff. Sputter Yield [atoms/ion/steradian]
Present Study Shutthanandan Zoerb
ᅗ 7 ᚤศࢫࣃࢵࢱ⋡ ᅗ 8 500eV࠾ࡅࡿᚤศࢫࣃࢵࢱ⋡ࡢᩥ⊩್ࡢẚ㍑
ᚓࡽࢀࡓᅗ㸵ࡢ⤖ᯝࡽ㸪ᮏᐇ㦂࡛ᚓࡽࢀࡓᚤศࢫࣃࢵࢱ⋡ࡢ್᭱ࡣȘࡀ 40 ~ 50 deg ࡢࡁ࡛࠶ࡗࡓ㸬ࡲ
ࡓ㸪ᅗ㸶࠾ࡅࡿࡢᩥ⊩್ࡢẚ㍑⤖ᯝࡼࡾ㸪ᮏᐇ㦂࡚Multiple QCM System࡛ྲྀᚓࡋࡓศᕸࡣࡢᐇ㦂
ࡼࡾᚓࡽࢀ࡚࠸ࡿศᕸྠᵝࡢഴྥࢆ♧ࡋ࡚࠾ࡾ㸪≉Shutthanandanࡣࡰྠᵝࡢ್ࢆᚓࡓ㸬ࡇࢀࡽࡢ
⤖ᯝࡼࡾ㸪ᅇࡢᐇ㦂࡚᪂ࡓヨࡳࡓ ᐃ᪉ἲࡢ᭷ຠᛶࡀ☜ㄆࡉࢀࡓ㸬 4. ࠾ࢃࡾ
ᮏ◊✲࡛ࡣ㸪ከࢳࣕࣥࢿ࡛ࣝࡢィ ࡢඛ㥑ࡅࡋ࡚᪂ࡓMultiple QCM Systemࢆస〇ࡋ㸪ࡑࡢጇᙜᛶホ౯ ࡢࡓࡵ࢟ࢭࣀࣥ࢜ࣥࣅ࣮࣒ࢆࣔࣜࣈࢹࣥࢱ࣮ࢤࢵࢺ↷ᑕࡋ㸪ࢫࣃࢵࢱ⋡ཬࡧᚤศࢫࣃࢵࢱ⋡ࡢ ᐃࢆ⾜࡞
ࡗࡓ㸬ࡑࡢ⤖ᯝ㸪ࢫࣃࢵࢱ⋡ཬࡧᚤศࢫࣃࢵࢱ⋡ࡣࡑࢀࡒࢀࡢᩥ⊩್ྠᵝࡢഴྥࢆᚓࡓ㸬ࡋࡓࡀࡗ࡚㸪ᅇ
⾜ࡗࡓᐇ㦂ᡭἲ࠾ࡅࡿᐇ㦂ࡢጇᙜᛶMultiple QCM Systemࡢ᭷ຠᛶࢆ♧ࡍࡇࡀ࡛ࡁࡓゝ࠼ࡿ㸬
ᚋࡣ㸪ࢱ࣮ࢤࢵࢺࡢࣅ࣮࣒ࡢධᑕゅࢆኚ᭦ࡋࡓᐇ㦂㸪ࡼࡾప࢚ࢿࣝࢠ࣮㡿ᇦ࠾ࡅࡿࢫࣃࢵࢱࣜࣥࢢ≉ᛶ ࡢ ᐃ㸪ࣔࣜࣈࢹࣥࡽ࢚࢜ࣥࣥࢪࣥࢢࣜࢵࢻᮦᩱ࡛࠶ࡿC-C」ྜᮦࢆ⏝࠸ࡓᐇ㦂㸪➼ࢆ⾜࠺ணᐃ࡛࠶ࡿ㸬
ཧ⪃ᩥ⊩
[1] Koizumi, H., Kuninaka, H., “Antenna Design Method and Performance Improvement of a Micro-Ion Engine Using Microwave Discharge”, 26th International Symposium on Space Technology and Science, ISTS 2008-b-29, 2008.
[2] ᫂ᫍ㟁Ẽᰴᘧ♫, ”ᖹᡂ㸯㸶ᖺᗘ Ᏹᐂ⏝QCMࡢ᳨ウཬࡧヨస ᡂᯝሗ࿌᭩”, JX-PSPC-211868, 2007.
[3] Kirk A. Zoerb, John D. Williams, Desiree D. Williams, and Azer P. Yalin ”Differential Sputtering
䃐=30㼻 䃐=30㼻
䃐=60㼻 䃐=60㼻
Ion beam Ion beam
58 宇宙航空研究開発機構研究開発報告 JAXA–RR–09–004
Yields of Refractory Metals by Xenon, Krypton, and Argon Ion Bombardment at Normal and Oblique Incidences”, IEPC-2005-293, 2005.
[4] Tartz, M., Neumann, H., Fritsche, B., Leiter, H., and Esch, J., “Investigation of Sputter Behavior of Ion Thruster Grid Materials,” 40th Joint Propulsion Conference, AIAA - 2004-4114, 2004.
[5] Kolasinki, R.D., “Oblique Angle Sputtering Yield Measurements for Ion Thruster Grid Materials”, 41st Joint Propulsion Conference, AIAA -2005-3526, 2005.
[6] Yamamura, Y., Tawara, H., “Energy Dependence of Ion-induced Sputtering Yields from Monatomic Solid at Normal Incidence,” Atomic Data and Nuclear Tables, Vol.62, No.2, pp.149-253, 1996.
[7] Shutthanan, V., Ray, P., Shivaparan, N., Smith, R., Thevuthasan, T., and Manteniek, M., “On the Measurement of Low-energy Sputtering Yield Using Rutherford Backscattering Spectrometry”, 25th International Electric Propulsion Conference, IEPC paper 97-069.
