ͷͲͳ17‫⤂✲◊ڦ‬௓᪉ྥឤᗘࢆᣢࡘᬯ㯮≀㉁᥈⣴ᐇ㦂 NEWSdm ࡜㉸ᚤ⢏ᏊཎᏊ᰾஝ᯈᢏ⾡ᮾ㑥኱Ꮫ ⣲⢏Ꮚ≀⌮Ꮫᩍᐊ୰㻌 ❳኱tatsuhiro.naka@sci.toho-u.ac.jp
2019 ᖺ 䠄௧࿴ඖᖺ䠅 5 ᭶ 11 ᪥1 ࡣࡌࡵ࡟

䛷䛿䠈ᬯ㯮≀㉁䜢ᩘ༑ GeV/c2 ௨ୖ䛾㉁㔞䜢ᣢ䛴 Weakly Inter-1.1 ᴫせ䛻䛚䛡䜛ᬯ㯮≀㉁䛾⇕ⓗ⏕ᡂ䝥䝻䝉䝇䛸⌧ᅾ䛾Ꮡᅾẚ䛸䛾ᩚacting Massive Particles (WIMP)䛸௬ᐃ䛩䜛䚹䛣䜜䛿䠈ึᮇᏱᐂᏱᐂ䛻䛚䛡䜛ᬯ㯮≀㉁ၥ㢟䛿䠈ゝ䜟䛪䛸▱䜜䛯⮬↛⛉Ꮫ䛻䛚䛡䜛᭱㔜せㄢ㢟䛾୍䛴䛷䛒䜚䠈Ᏹᐂ䛾ᵓ㐀ᙧᡂ䛻䛚䛔䛶୺ྜᛶ䛻䜘䜛 weak scale 䛾ᮍ▱⢏Ꮚ[7]䛷䛒䜛䛸䛔䛖ほⅬ䛛䜙ጇᙜ䛺䝰䝕䝹䛷䛒䜛䛸⪃䛘䜙䜜䜛䛯䜑䛷䛒䜛䚹せ䛺ᙺ๭䜢ᢸ䛳䛶䛔䜛ᮍ▱䛾㔜ຊ※䛷䛒䜛䚹ྠ᫬䛻䠈⣲⢏Ꮚᶆ➹⪅䛿䠈≉䛻䠈ᬯ㯮≀㉁䛾฿᮶᪉ྥ᝟ሗ䜢ᤊ䛘䜛䛣䛸䜢┠ⓗ‽ᶍᆺ䜢㉸䛘䛯᪂䛯䛺⣲⢏Ꮚ䛷䛒䜛ྍ⬟ᛶ䛜㧗䛔䛣䛸䛛䜙䠈䛭䛸䛧䛯ᬯ㯮≀㉁᥈⣴ᐇ㦂[8]䛻㛵ᚰ䜢ᣢ䛱䠈◊✲䜢㐍䜑䛶䛔䜛䚹䛾ṇయ䛻䛴䛔䛶ㄡ䛧䜒䛜▱䜚䛯䛔䛸ᛮ䛳䛶䛔䜛(䛿䛪䛷䛒䜛)䚹

ᬯ㯮≀㉁䛻䜘䜛཯㊴䛥䜜䜛ཎᏊ᰾䛾཯㊴㊥㞳䛿ᴟ䜑䛶▷䛔䛯ᬯ㯮≀㉁(dark matter)䛾Ṕྐ䛿ྂ䛟䠈1932 ᖺ䛾 J. Ort[1]䠈䜑䠈⌧ᅾ䠈䜺䝇䜢⏝䛔䛯᳨ฟᐇ㦂䛜ඛ⾜䛧䛶䛔䜛䛜[9]䠈䜘䜚ᶆ1937 ᖺ䛾 F. Zwicky[2][3]䛻䜘䛳䛶䛩䛷䛻 dark matter 䛸䛔䛖ゝⓗ㔜㔞䜢㧗䜑䛯ᅛయ䠄䜒䛧䛟䛿ᾮయ䠅᳨ฟჾ䛷䛾ྍ⬟ᛶ䛻䛴䛔ⴥ䛜౑䜟䜜䠈㖟Ἑ䠄ᅋ䠅ෆ䛻኱㔞䛾ᮍ▱䛾㔜ຊ※䛜Ꮡᅾ䛧䛶䛔䛶◊✲䛩䜛䛣䛸䛿ᑗ᮶䛾኱つᶍ໬䛸᪂䛯䛺᪉ἲㄽ䛾㛤ᣅ䛻䛸䛳䜛䛣䛸䛜ᣦ᦬䛥䜜䛶䛔䜛䚹⌧ᅾ䛾ᬯ㯮≀㉁ၥ㢟䛾㆟ㄽ䛿䠈1970䛶ᴟ䜑䛶㔜せ䛷䛒䜛䠄䛭䛾཯㠃䠈㠀ᖖ䛻䝏䝱䝺䞁䝆䞁䜾䛷䛒䜛䠅䚹ᖺ௦䛾 Vera Rubin 䛾㖟Ἑ䛾ᅇ㌿㏿ᗘ䛾䜰䝜䝬䝸䞊[4]䛛䜙⥆䛔⌧ᅾ䠈ᡃ䚻䛿䠈᪥ᮏ䠈䜲䝍䝸䜰䠈䝻䝅䜰䠈䝖䝹䝁䠈㡑ᅜ䛛䜙䛺䜛ᅜ䛶䛔䜛䛸⌮ゎ䛧䛶䛔䜛䛜䠈㏆ᖺ䛾Ᏹᐂほ䛻䜘䛳䛶䠈䛥䜎䛦䜎䛺㝿ඹྠᐇ㦂 NEWSdm (Nuclear Emulsion for WIMP Search –㻌䝇䜿䞊䝹䛷ᬯ㯮≀㉁䛜Ꮡᅾ䛩䜛ドᣐ䛜ᚓ䜙䜜䛶䛔䜛䚹䛯䛰䛧䠈directional measurement) [10]䜢❧䛱ୖ䛢䛶䛔䜛䚹ṧᛕ䛺䛜䜙䠈ᡃ䚻䛜ᬯ㯮≀㉁䛾┤᥋᳨ฟ䜢⾜䛖ሙྜ䠈䛭䛾ᑐ㇟䛿䠈ኳ䛾ᕝ⌧ᅾ䛿䜎䛰 R&D 䝣䜵䞊䝈䛷䛒䜚䠈ᮏᐇ㦂䜢⾜䛖ẁ㝵䛷䛿䛺䛔䛜䠈㖟Ἑ䛻Ꮡᅾ䛩䜛ᬯ㯮≀㉁䛷䛒䜛䚹䛣䜜䛿䠈䛩䛷䛻ᅇ㌿㏿ᗘ䛾ᮏグ஦䛷䛿䠈䛣䜜䜎䛷䛾◊✲䛻⮳䜛⤒⦋䛸 NEWSdm ᐇ㦂䛻䛚ᐃ䛻䜘䛳䛶䛭䛾Ꮡᅾ㔞䛜⌮ゎ䛥䜜䛶䛚䜚䠈⣙ 0.4GeV/cm

䛡䜛㠀ᖖ䛻䝴䝙䞊䜽䛺䝔䜽䝜䝻䝆䞊䜢⤂௓䛧䠈⌧≧䛸ᒎᮃ䛻䛴䛔3 䛾䜶䝛䝹䜼䞊ᐦᗘ䜢ᣢ䛴[5][6]䚹౛䛘䜀䠈ᬯ㯮≀㉁䛾㉁㔞䛜ཎᏊ㉁㔞⛬ᗘ䛰䛸䛩䜛䛸䠈ᆅ⌫ୖ䛷䛾䝣䝷䝑䜽䝇䛿 10

5-6/cm2/sec 䛻┦ᙜ䛩䜛䚹䛱䛺䜏䛻䠈Ᏹᐂ඲య䛾ᬯ㯮≀㉁䛾䜶䝛䝹䜼䞊ᐦᗘ䜢ᖹᆒ໬䛩䜛䛸䠈Ᏹᐂ䛾⮫⏺ᐦᗘ 5 keV/cm

3䠈CMB

䛾ほ

䛛䜙

䛶ሗ࿌䛩䜛䚹

2. ཎᏊ᰾஝ᯈࢆ⏝࠸ࡓᬯ㯮≀㉁᥈⣴2.1 ⤒⦋䃈DM 䛜 0.27 䛸䛩䜛䛸 1.35 keV/cm3 䛷䛒䜚䠈ኳ䛾ᕝ㖟Ἑෆ䛾ᬯᶆ‽ⓗ䛺ᬯ㯮≀㉁䝰䝕䝹䠄WIMP 䛛䛴 Maxwell ศᕸ䛻ᚑ䛖㯮≀㉁䛿䠈Ᏹᐂ඲య䛾ᖹᆒ䛻ᑐ䛧䛶⣙ 20 ୓ಸ⃰䛔≧ែ䛷Ꮡ㏿ᗘศᕸ䜢ᣢ䛴䠅䜢௬ᐃ䛧䛯ሙྜ䠈ᅛయ୰䛷䛾཯㊴ཎᏊ᰾䛾ᅾ䛧䛶䛔䜛䛸᥎ᐃ䛥䜜䜛䚹㣕⛬䛿䠈ᅗ 1 䛻♧䛩䜘䛖䛻䛫䛔䛬䛔ᩘⓒ nm ⛬ᗘ䛸䛺䜛䚹1μmᬯ㯮≀㉁䛾┤᥋᳨ฟ䛿䠈䛹䛾䜘䛖䛺ᬯ㯮≀㉁䜢௬ᐃ䛩䜛䛛䜒‶䛯䛺䛔⢏Ꮚ㣕㊧䜢᳨ฟ䛷䛝䜛ᢏ⾡䛿➹⪅䛜▱䜛㝈䜚Ꮡᅾ䛧䛻䜘䛳䛶᳨ฟჾ䛾ᵓ㐀䜔᪉ἲㄽ䛜ኚ䜟䛳䛶䛟䜛䚹ᡃ䚻䛿ᬯ㯮≀䛺䛛䛳䛯䚹㻌 ➹⪅䛜኱Ꮫ㝔䛷䛾◊✲䝔䞊䝬䜢᥈䛧䛶䛔䜛䛸䛝䛻䠈㉁䛾ṇయ䛻䛴䛔䛶඲䛟ศ䛛䛳䛶䛔䛺䛔䛯䜑䠈䛥䜎䛦䜎䛺ᐇ㦂䜾䛯䜎䛯䜎ゼၥ䛧䛯ྡྂᒇ኱Ꮫ F ◊✲ᐊ䛻䠈୹⩚බ㞝ᩍᤵ䠄ᙜ᫬䠅䝹䞊䝥䛜ྛ䚻䛾䝔䜽䝜䝻䝆䞊䜢㥑౑䛧䠈◊✲㛤Ⓨ䛚䜘䜃ᐇ㦂䜢䛜ఇ᪥䛻䜒ᣊ䜟䜙䛪അ↛ᒃ䜙䜜䠈䠄ᬑ㏻䛿䛭䜣䛺䛣䛸䛧䛶䛟䜜䛺㐍䜑䛶䛚䜚䠈᳨ฟᢏ⾡䛾ഃ㠃䛛䜙䜒㠃ⓑ䛔ศ㔝䛷䛒䜛䚹᪂䛧䛔䛔䜙䛧䛔䛜䠅┤䚻䛻◊✲ᐊ䜢᱌ෆ䛧䛶䛔䛯䛰䛝䠈ཎᏊ᰾஝ᯈ䛾䜰䜲䝕䜱䜰䛜ᚲせ䛻䛺䜛⌮⏤䛾୍䛴䛿䠈ᬯ㯮≀㉁䛿ᵓ㐀ᙧᡂ㧗䛔✵㛫ศゎ⬟䜢⏕䛛䛧䛶ᬯ㯮≀㉁䛾᳨ฟᐇ㦂䜢䜔䜚䛯䛔䛛䛾ほⅬ䛛䜙ᩘⓒ km/sec ⛬ᗘ䛸䛔䛖㠀ᖖ䛻㐜䛔㏿ᗘ䜢ᣢ䛳䛶䛔䜙䜔䜜䜛ே㛫䜢᥈䛧䛶䛔䜛䛸ゝ䜟䜜䛯䛾䛜䛝䛳䛛䛡䛷䛒䜛䚹ಶே-3 ⛬䜛䛯䜑䛷䛒䜛䚹䛴䜎䜚䠈㧗䜶䝛䝹䜼䞊≀⌮䛸䛿㐪䛔䠈䃑~ 10ⓗ䛻᭱䜒㨩ຊⓗ䛰䛳䛯䛾䛿䠈ᙜ᫬䛭䛾◊✲䜢䜔䛳䛶䛔䛯䛾䛿ᗘ䛾⢏Ꮚ䜢᳨ฟ䛩䜛ᚲせ䛜䛒䜚䠈᳨ฟჾ䛾ᛂ⟅ཬ䜃⫼ᬒ஦㇟኱Ꮫ㝔⏕䛾ኟ┠Ặ䛰䛡䛷䠈㠀ᖖ䛻ึᮇ䛾ཎ⌮ᐇド◊✲䛾ศ㞳䛻䛚䛔䛶䛥䜎䛦䜎䛺᪂䛧䛔ᢏ⾡䜔▱ぢ䛜せồ䛥䜜䜛䚹௨㝆䝣䜵䞊䝈䛷䛒䛳䛯䛯䜑䠈ほᐇ㦂䛹䛣䜝䛛᳨ฟჾ䛸䛧䛶䛾ཎᆺ䛜䜋䜌䛺䛔≧ែ䛷䛒䛳䛯䛣䛸䛷䛒䜛䚹⮬䜙㛤Ⓨ䛧䛯᳨ฟჾ䛷䠈⊂

ͷͲʹ
18

⮬䛾ᐇ㦂䜢䜔䜚䛯䛔䛸ᛮ䛳䛶䛔䛯➹⪅䛻䛸䛳䛶䛿䛒䜛ព࿡䛷䛿≧䛾⌧ീ㖟䛜ᡂ㛗䛧䠈⢏Ꮚ䛾㌶㊧䛻ἢ䛳䛯⌧ീ㖟䛾୪䜃䛸䛧᭱㧗䛾⎔ቃ䛷䛒䛳䛯䚹䛶ගᏛ㢧ᚤ㙾䛷㣕㊧䛜᳨ฟ䛥䜜䜛䚹

ᅗ 3 ཎᏊ᰾஝ᯈࡢ⢏Ꮚ᳨ฟཎ⌮ࡢᴫᛕᅗ䛣䛾₯ീ᰾䛾ᙧᡂ䝥䝻䝉䝇䛿䠈ᅗ 4 䛾䝞䞁䝗ᵓ㐀ෆ䛾ᴫᛕᅗ
ᅗ 1 ᅛయ୰㸦ࡇࡇ࡛ࡣᡃࠎࡢࢹࣂ࢖ࢫࢆ᝿ᐃ㸧࡛ࡢᬯ㯮䛷ㄝ᫂䛥䜜䜛䚹AgBr(I)⤖ᬗෆ䛷Ⲵ㟁⢏Ꮚ䛾㟁㞳స⏝䜘䜚⏕䛨≀㉁ࡢ㉁㔞ࡈ࡜ࡢ཯㊴ཎᏊ᰾㣕⛬ࢫ࣌ࢡࢺࣝ

䜛㟁Ꮚ-ṇᏍ(e-h)ᑐ䛿䠈෌⤖ྜ䛻䜘䜚ᾘኻ䛩䜛๭ྜ䜒୍ᐃ㔞䛒

2.2 ཎᏊ᰾஝ᯈ

䜛䛜䠈⤖ᬗ⾲㠃䛻㟁Ꮚ䝖䝷䝑䝥䛜Ꮡᅾ䛩䜛䛯䜑㟁Ꮚ䛿䛭䛣䛻ᤕ⋓䛥䜜䜛䚹AgBr(I)⤖ᬗ䛿䠈᱁Ꮚ㛫㖟䜲䜸䞁䛻䜘䜛ఏᑟᗘ䜢ᣢ䛳㻌 ཎᏊ᰾஝ᯈ䛿䠈㏆ᖺ䛷䛿䝙䝳䞊䝖䝸䝜ᐇ㦂䠄㧗䜶䝛䝹䜼䞊䛶䛚䜚䠈䛣䜜䛜䝖䝷䝑䝥䛥䜜䛯㟁Ꮚ䛸䜽䞊䝻䞁┦஫స⏝䛻䜘䜚⤖ྜ䝙䝳䞊䝇 [11]ཧ↷䠅➼䛷䛭䜜䛺䜚䛻▱䜙䜜䛶䛿䛔䜛䛜䠈䛭䛾᳨䛧䠈㖟䛾䜽䝷䝇䝍䞊䜢⏕ᡂ䛩䜛䚹⏕ᡂ䛧䛯㖟䛾䜽䝷䝇䝍䞊䛿䛥䜙䛻ฟཎ⌮䛻䛴䛔䛶䛿䛒䜎䜚⌮ゎ䛥䜜䛶䛔䛺䛔䛸ᛮ䛖䛧䠈䝴䞊䝄䞊῝䛔㟁Ꮚ䝖䝷䝑䝥䛸䛺䜛䛯䜑䠈㐃⥆䛧䛶㖟䛾 2 㔞య䠈3 㔞య䜢ᙧ⮬㌟䜒䛒䜎䜚䛭䜜䜢⌮ゎ䛥䜜䛶䛔䛺䛔ሙྜ䜒䛒䜛䛾䛷䠈䛣䛣䛷ᨵᡂ䛧䠈4 㔞య䛾≧ែ䛷୍⯡ⓗ䛺⌧ീᾮ䛻䛚䛔䛶⌧ീ䛥䜜䜛䚹䛣䜑䛶⡆༢䛻⤂௓䛩䜛䚹䛾䜘䛖䛺⌧ീྍ⬟䛸䛺䛳䛯㖟䜽䝷䝇䝍䞊䜢₯ീ᰾䛸䛔䛖䚹⌧ീ䝥㻌 ཎᏊ᰾஝ᯈ䛿䠈䝊䝷䝏䞁୰䛻䝝䝻䝀䞁໬㖟⤖ᬗ䠄䛣䛣䛷䛿䝻䝉䝇䛿䠈ᇶᮏⓗ䛻䛿㑏ඖ཯ᛂ䛷䛒䜚䠈⌧ീᾮ䛛䜙㟁Ꮚ䛜౪⤥

AgBr(I)⤖ᬗ䠅䛜ศᩓ䛥䜜䛯ᵓ㐀䜢ᣢ䛱䠈䛭䛾፹య䜢ங๣䛸࿧䜣䛥䜜䠈ྠ᫬䛻ෆ㒊䛾᱁Ꮚ㛫㖟䜲䜸䞁䜢౑䛳䛶₯ീ᰾䛜ቑᖜ䛥䜜䛷䛔䜛䚹䛣䜜䛿䠈⌧ᅾ䛷䛿䛒䜎䜚౑䜟䜜䛺䛟䛺䛳䛯㖟ሷ෗┿䝣䜱䜛䚹䛣䛾ቑᖜ⋡䛿ᩘ༑൨ಸ䛻┦ᙜ䛩䜛䚹୍⯡ⓗ䛻䠈₯ീ᰾䛾኱䝹䝮䛾୍✀䛷䛒䜛䚹ཎᏊ᰾஝ᯈ䛾ሙྜ⤖ᬗ䝃䜲䝈䛿䠈ᶆ‽ⓗ䛝䛥䛜኱䛝䛔䜋䛹㓟໬㑏ඖ཯ᛂ䛻䛚䛡䜛άᛶ໬䜶䝛䝹䜼䞊䛜䛻䛿⣙ 200nm ⛬ᗘ䛾䜒䛾䛜⏝䛔䜙䜜䜛[12]䚹㏻ᖖ౑䜟䜜䛶䛔䜛ప䛟䛺䜛䛯䜑⌧ീ㏿ᗘ䛿 exponential 䛻ቑຍ䛩䜛(Nernst 䛾ᐃ෗┿䝣䜱䝹䝮䛿 1μm ⛬ᗘ䛾┤ᚄ䜢ᣢ䛴䛔䜟䜖䜛ᖹᯈ⢏Ꮚ䠄ᅗ⌮)䚹䛣䛾₯ീ᰾䝃䜲䝈䠄䛚䜘䜃ᩘ䠅䛿䠈㏻㐣䛧䛯Ⲵ㟁⢏Ꮚ䛾

2(a)䠅䛷䛒䜚䠈ཷග㠃䜢ᗈ䛢䜛䛣䛸䛻䜘䜚ග䛻ᑐ䛩䜛㔞Ꮚຠ⋡䜢

dE/dx 䛻౫Ꮡ䛩䜛䛯䜑䠈⌧ീ㏿ᗘ䜔⌧ീ㖟䛾኱䛝䛥䞉ᙧ≧䜒ྥୖ䛥䛫䛶䛔䜛䚹ཎᏊ᰾஝ᯈ䛾ሙྜ䠈䛭䜜䛷䛿⢏Ꮚ䛾᪉ྥ䛻

dE/dx 䛻౫Ꮡ䛩䜛䠄䛧䛛䛧䠈䛣䛾᝟ሗ䛿ගᏛศゎ⬟௨ୗ䛾䝇ᑐ䛧␗᪉ᛶ䛜⏕䛨䛶䛧䜎䛖䛯䜑䠈䜘䜚⌫䛻㏆䛔⤖ᬗ䛷ᵓᡂ䛥䜜䛶䜿䞊䝹䛷䛒䜛䛯䜑䠈୍⌧ീ㖟䛿 0/1 䛾᝟ሗ䛧䛛ᣢ䛯䛺䛔䛸
䞉

䞉

䞉

䞉

䞉

ᛮ䜟䜜䛜䛱䛷䛒䜛䠅䚹ᅗ 2 ࣁࣟࢤࣥ໬㖟⤖ᬗࡢ㟁Ꮚ㢧ᚤ㙾⏬ീ (a) ୍⯡ⓗ࡞෗┿ࣇ࢕࣒ࣝ (b) ᚑ᮶ࡢཎᏊ᰾஝ᯈ, (c) ㉸ᚤ⢏ᏊཎᏊ᰾஝ᯈ
㸦Nano Imaging Tracker㸧䛚䜚䠈ᐇ㝿䛻䛿 8 㠃య䛾ゅ䛜䛸䜜䛯䜘䛖䛺⤖ᬗ䛸䛺䛳䛶䛔䜛䠄ᅗ

ᅗ4

AgBr(I)⤖ᬗࡢࣂࣥࢻᵓ㐀ෆ࡟࠾ࡅࡿ₯ീᙧᡂ

2(b)䠅䚹ங๣ᒙ䛿⣙ 10-100μm ⛬ᗘ䛷䛒䜛䠄ཎ⌮ⓗ䛻ཌ䜏䛾ไࣉࣟࢭࢫࡢᴫᛕᅗ

㝈䛿䛺䛔䛜䠈⌧ീᾮ䛾ᾐ㏱䜔㢧ᚤ㙾䛾䝽䞊䜻䞁䜾䝕䜱䝇䝍䞁䝇ᅗ 3 䛛䜙᝿ീ䛷䛝䜛䛸ᛮ䛖䛜䠈ཎᏊ᰾஝ᯈ䛻䛚䛡䜛✵㛫ศゎ䛛䜙ไ㝈䛜᮶䜛䠅䚹ศᩓ䛥䜜䛯 AgBr(I)⤖ᬗ䜢Ⲵ㟁⢏Ꮚ䛜㈏㏻䛧

⬟䛿䠈AgBr䠄I䠅⤖ᬗ䛾䝃䜲䝈䛸ᐦᗘ䛷Ỵ䜎䜚䠈䛥䜙䛻⤖ᬗ䛾Ⲵ㟁䛯ሙྜ䠈ᅗ 3 䛾ᴫᛕᅗ䛾䜘䛖䛻䠈㟁㞳స⏝䛻䜘䛳䛶₯ീ᰾䛸࿧⢏Ꮚ䛻ᑐ䛩䜛཯ᛂ☜⋡䠄⌧ീ☜⋡䠅䛿䠈₯ീᙧᡂຠ⋡䛚䜘䜃⌧䜀䜜䜛㖟䛾䜽䝷䝇䝍䞊䛜୺䛻⤖ᬗ⾲㠃䛻ᙧᡂ䛥䜜䜛䚹₯ീ᰾䛿䠈ീάᛶ䛻䜘䛳䛶Ỵ䜎䜛䚹䛴䜎䜚䠈䛣䜜䜙䛾≧ែ䜢䝁䞁䝖䝻䞊䝹䛷䛝⌧ീᾮ䛻䛚䛡䜛䝖䝸䜺䞊䛸䛺䛳䛶䠈㏻ᖖ䛾⌧ീᾮ䛷䛿䝣䜱䝷䝯䞁䝖䜜䜀䛥䜎䛦䜎䛺ᛂ⟅≉ᛶ䜢♧䛩䝕䝞䜲䝇䛜సᡂ䛷䛝䜛䜟䛡䛷䛒
䜛䚹

503
19

2008 ᖺ䛻ྡྂᒇ䛷㛤䛛䜜䛯 emulsion workshop 䛸䛔䛖఍ྜ䛷 Fuji Film 䛾ᢏ⾡⪅䞉◊✲⪅䛾᪉䛸㆟ㄽ䛩䜛ᶵ఍䛜䛒䜚䠈䛭䛖グ㘓䛥䜜䛯㣕㊧䛿䠈ගᏛ㢧ᚤ㙾䛷ほᐹ䛩䜛䛣䛸䛜䛷䛝䠈⌧ᅾ䛔䛳䛯≧ἣ䜢┦ㄯ䛧䛯䛸䛣䜝䠈䛰䛳䛯䜙ཎᏊ᰾஝ᯈ䜢⮬ศ䛷䛿䠈⮬ື㣕㊧ㄞ䜏ྲྀ䜚⿦⨨䜢⏝䛔䛯஦㇟ゎᯒ䛜⾜䜟䜜䛶䛔䜛䚹స䛳䛯䜙䛹䛖䛰䛸䛔䛖ヰ䜢䛔䛯䛰䛔䛯䚹ᐇ䛿䠈ཎᏊ᰾஝ᯈ䛿䠈䛒౛䛘䜀䠈ྡྂᒇ኱Ꮫ➼䛜⾜䛳䛶䛔䜛㣕㊧ㄞ䜏ྲྀ䜚䛿䠈」ᩘ䛾ཎᏊ᰾஝ᯈ䜢㈏䛝䠈୍ᯛ䛒䛯䜚䛾ཎᏊ᰾஝ᯈ䛻ᑐ䛧䛶┤⥺ᛶ䛾㧗䛔䠄㧗䜶䝛䝹䜼䞊䠅䛾㣕㊧䜢䛴䛺䛞ྜ䜟䛫䜛䛣䛸䛷䠈஦㇟෌ᵓᡂ䜢⾜䛔䠈཯ᛂゎᯒ䜢⾜䛖䛣䛸䛜୍⯡ⓗ䛷䛒䜛䚹䛧䛛䛧䛺䛜䜙䠈ᮏ◊✲䛻䛚䛔䛶䛿䠈䛭䜜䜎䛷㛤Ⓨ䛥䜜䛶䛝䛯䝕䝞䜲䝇䜔⮬ືㄞ䜏ྲྀ䜚ἲ䛿㐺⏝䛷䛝䛺䛔䚹䛭䛾⌮⏤䛸䛧䛶䠈✵㛫ศゎ⬟䛜㧗䛔䛸ゝ䛔䛴䛴䜒䠈ᬯ㯮≀㉁᳨ฟ䛷せồ䛩䜛 1μm ௨ୗ䛾㣕㊧᳨ฟ䛜䛷䛝䜛䜋䛹䛾✵㛫ศゎ⬟䜢ᣢ䛯䛺䛔䛣䛸䠈1μm ௨ୗ䛸䛔䛖ᴟ▷㣕㊧䜢ㄞ䜏ฟ䛩ㄞ䜏ྲྀ䜚䝅䝇䝔䝮䛚䜘䜃஦㇟ゎᯒ᪉ἲㄽ䛜Ꮡᅾ䛧䛺䛔䛣䛸䠈᳨ฟჾ䛾ᛂ⟅䜢ไᚚ䛩䜛᪉ἲ䛜䛺䛔䠄▱䜙䛺䛔䠅

ᅗ 5 ཎᏊ᰾஝ᯈ⏝ங๣〇㐀⿦⨨䛣䛸䛜ᣲ䛢䜙䜜䜛䚹䛣䜜䛿ᮏ◊✲䜢᥎㐍䛩䜛䛖䛘䛷⮴࿨ⓗ䛺ၥ㢟䛷䛒䛳䛯䚹䛣䜜䜙䛾ㄢ㢟䜢䛹䛖ඞ᭹䛧䛶䛝䛯䛛䛻䛴䛔䛶ḟ❶䛷䜎䜚䛻䝜䜴䝝䜴䛜䛒䜚䛩䛞䛶෗┿఍♫䛻䛧䛛〇㐀䛿䛷䛝䛺䛔䛸䛥㏙䜉䜛䚹

䜣䛦䜣ᩍ⫱䛥䜜䛶䛝䛯䛜䠈ᐇ㝿䛻෗┿䝣䜱䝹䝮䜢㛤Ⓨ䛧䛶䛝䛯᪉䚻䛾ゝⴥ䜢ಙ⏝䛧䠈୰ᮧᩍᤵ䠄ᙜ᫬䠈෸ᩍᤵ䠅䛸୍䛴୍䛴䛭

3. ᬯ㯮≀㉁᳨ฟࢆྍ⬟࡟ࡍࡿᢏ⾡㛤Ⓨ
3.1 ࢹࣂ࢖ࢫ㛤Ⓨ䛾ྍ⬟ᛶ䜢᥈䛳䛶䛔䛳䛯䚹⣙୍ᖺⰍ䚻䛸㆟ㄽ䜢㔜䛽䠈䝩䝻䜾䝷䝣䜱䝣䜱䝹䝮䛾సᡂ⤒㦂䛾䛒䜛◊✲⪅䛸ඹྠ◊✲䜒⾜䛔䛺䛜䜙䠈⤖ᬗ䝃䜲䝈䛜 100nm ௨ୖ䛒䜛䛸䠈᳨ฟྍ⬟䛺㣕㊧㛗䛿䛫䛔᭱⤊ⓗ䛻䛿 Fuji Janet䠄Fuji Fi䡈䡉䛾⿦⨨㛤Ⓨ䜢⾜䛳䛶䛝䛯఍♫䠅䛬䛔ᩘ μm ௨ୖ䛸䛺䛳䛶䛧䜎䛔䠈䛣䜜䛿ᙜ↛䝃䝤䝭䜽䝻䞁䛾㣕㊧䛾㟢ᮌ♫㛗䛾඲㠃ⓗ䛺༠ຊ䛜ᚓ䜙䜜䠈2010 ᖺ䛻◊✲ᐊ䝺䝧䝹᳨ฟ䛿䛷䛝䛺䛔䛯䜑䠈䛥䜙䛻✵㛫ศゎ⬟䜢ྥୖ䛥䛫䜛ᚲせ䛜䛒䛷〇㐀ྍ⬟䛺䜘䛖䛻タィ䛥䜜䛯ཎᏊ᰾஝ᯈ䛾〇㐀⿦⨨䠄ᅗ 5䠅

䜛䚹ඛ䛻㏙䜉䛯䜘䛖䛻䠈✵㛫ศゎ⬟䛿䝢䜽䝉䝹䝉䞁䝃䞊䛸䛧䛶䛾䜢ྡྂᒇ኱Ꮫ䜈ᑟධ䛧䠈Fuji Film OB 䛷 OPERA ᐇ㦂⏝ཎᏊᶵ⬟䜢ᯝ䛯䛧䛶䛔䜛 AgBr(I)⤖ᬗ䛾䝃䜲䝈䛸ᐦᗘ䛻౫Ꮡ䛩䜛䚹᰾஝ᯈ䛾㛤Ⓨ䛻ᚑ஦䛥䜜䛯᱓ཎẶ䛸ඹ䛻ཎᏊ᰾஝ᯈ䛾㛤Ⓨ䛻⤖ᬗᐦᗘ䛿᭱ᐦ඘ሸ䛻㏆䛔䛸䛣䜝䜎䛷㧗ᐦᗘ໬䛥䜜䛶䛔䜛䛯䜑䠈╔ᡭ䛧䛯䚹⤖ᬗ䝃䜲䝈䜢ᚤ⣽໬䛧䛯䛔䜟䜖䜛㉸ᚤ⢏ᏊཎᏊ᰾஝ᯈ䛜㧗✵ᙜึ䛾┠ⓗ䛷䛒䜛㉸ᚤ⢏ᏊཎᏊ᰾஝ᯈ䛾㛤Ⓨ䛿䠈᭱ึ䛾⤖㛫ศゎ⬟໬䛻䛚䛡䜛ᮏ㉁ⓗ䛺ゎ䛸䛺䜛䚹ᙜึ䛿 Fuji Film 䛾༠ᬗᡂ㛗䛻㛵䛧䛶䛿ពእ䛻䛩䜣䛺䜚䛔䛳䛯䛜䠈䜔䛿䜚⤖ᬗ䛾จ㞟ຊ䜢ᚓ䛶㛤Ⓨ䛜⾜䜟䜜䠄䛣䜜䛿ྠᵝ䛻㉸ᚤ⢏Ꮚ⤖ᬗ䜢⏝䛔䜛ၥ㢟䛻䜘䛳䛶Ᏻᐃᛶ䛜ᢸಖ䛥䜜䛺䛔≧ἣ䛷䛒䛳䛯䚹䛣䛾ゎỴ⟇䝩䝻䜾䝷䝣䜱෗┿䝣䜱䝹䝮䛾సᡂἲ䛜ᛂ⏝䛥䜜䛯䠅䠈⣙ 40nm 䛾䛸䛧䛶䠈䝫䝻䝡䝙䝹䜰䝹䝁䞊䝹䠄PVA䠅䜢 10%⛬ᗘῧຍ䛩䜛䛸䛔䛖⤖ᬗ䝃䜲䝈䜢ᣢ䛴ึ௦ Nano Imaging Tracker (NIT)䛜సᡂ䛥䜜䛣䛸䛜Ỵ䜑ᡭ䛸䛺䜚䠈㠀ᖖ䛻Ᏻᐃ䛧䛯⤖ᬗ䜢సᡂ䛷䛝䜛䜘䛖䛻䛯䚹䛣䜜䛿䠈ኟ┠Ặ䛻䜘䜚䠈䜲䜸䞁ὀධ⿦⨨䠄ྡྂᒇ኱Ꮫ䠈ඛ➃䛺䛳䛯䠄ᅗ 2(c)䠅䚹సᡂἲ䛻䛴䛔䛶䛿䠈[14][15] 䛻ヲ⣽䛻グ㍕䛥

ᢏ⾡ඹྠ฼⏝᪋タ䠅䜢⏝䛔䛶䠈␲ఝⓗ䛺ᬯ㯮≀㉁䜘䜛཯㊴ཎ䜜䛶䛔䜛䛯䜑ཧ↷䛥䜜䛯䛔䛜䠈⤖ᬗ䝃䜲䝈䛻䛴䛔䛶䠈ᅗ 6 䛷ぢᏊ᰾䛾ಙྕ䜢ప㏿䜲䜸䞁䛷௦⏝䛧䠈NIT 䛻ᡴ䛱㎸䜎䜜䛯஦㇟䜢㟁Ꮚ㢧ᚤ㙾䛷ほᐹ䛩䜛䛣䛸䛻䜘䜚䠈ᐇ㝿䛻䝃䝤䝭䜽䝻䛾㣕㊧᳨ฟ䛜䛷䛝䛶䛔䜛䛣䛸䜢☜ㄆ䛩䜛ᙧ䛷ཎ⌮ᐇド䛜䛺䛥䜜䛯[13]䚹䛣䜜
䛻䜘䜚䠈㉸ᚤ⢏ᏊཎᏊ᰾஝ᯈ䛸䛔䛖᪉ྥᛶ䛷䝃䝤䝭䜽䝻䞁䛾㣕㊧᳨ฟ䛜ྍ⬟䛷䛒䜛䛣䛸䛜ᐇド䛥䜜䛯䚹䛧䛛䛧䠈䛭䛣䛛䜙 Fuji Film
䛾㛤Ⓨ䛜䝇䝖䝑䝥䛧䠈䛣䜜௨ୖ䛾䝕䝞䜲䝇ᥦ౪䛜䛺䛥䜜䛺䛟䛺䛳䛯䚹䜎䛯䠈⤖ᬗ䜢㉸ᚤ⢏Ꮚ໬䛩䜛䛸䠈⤖ᬗ䛾⁐ゎᗘ䛜ୖ䛜䛳䛶䛧䜎䛖䛯䜑䠈䛔䜟䜖䜛䜸䝇䝖䝽䝹䝗⇍ᡂ䛸࿧䜀䜜䜛⌧㇟䛻䜘䛳䛶䝃䜲䝈ศᕸ䛾୰䛷ᑠ䛥䛔⤖ᬗ䛜䜘䜚᪩䛟⁐ゎ䛥䜜኱䛝䛺⤖ᬗ䛻ᯒฟ䛧䛶䛧䜎䛔䠈᭱⤊ⓗ䛻䛿ಖ⟶᫬䛾䝀䝹≧ែ୰䛻⤖ᬗ䝃䜲䝈䛜䛹䜣䛹䜣ᗈ䛜䛳䛶䛧䜎䛖䛸䛔䛖ၥ㢟䛜⏕䛨䛶䛧䜎䛔䠈◊✲䛭䛾䜒䛾䛜䜎䛸䜒䛻䛷䛝䛺䛔≧ἣ䛻㝗䛳䛯䚹䛭䜜䛻䜘䜚䠈➹⪅䛾㛤Ⓨ◊✲

ᅗ6

䛜䛧䜀䜙䛟೵⁫䛧䛶䛧䜎䛳䛶䛔䛯䚹ᕸࠋᖹᆒࢧ࢖ࢬ 10nm ௨ୗࡢ⢭ᗘ࡛ࢧ࢖ࢬࡢࢥࣥࢺ࣮ࣟࣝࡀ

㉸ᚤ⢏ᏊཎᏊ᰾஝ᯈ࡟࠾ࡅࡿ AgBr(I)⤖ᬗࡢࢧ࢖ࢬศ

ྍ⬟࡛࠶ࡿࠋ

504
20䜙䜜䜛䜘䛖䛻䠈䝃䜲䝈ศᩓ䛜⣙ 6 nm 䛻⣡䜎䜛䛣䛸䛜䛷䛝䠈ᖹᆒ䝃

50%䛾ຠ⋡䛷㣕㊧䜢ᵓᡂ䛷䛝䜛䛣䛸䛜䜟䛛䜚䠈䛥䜙䛻᪉఩ゅᗘศ䜲䝈䜒 10nm 䛾⢭ᗘ䛷䝁䞁䝖䝻䞊䝹䛷䛝䜛䜘䛖䛻䛺䛳䛶䛔䜛䚹ᶆ‽ゎ⬟䜒 0.6rad (⣙ 35㼻)⛬ᗘ䛜ᚓ䜙䜜䛶䛔䜛䚹ゅᗘศゎ⬟䛿䠈ᅛ

NIT 䛿䠈⤖ᬗ䝃䜲䝈䛜 44nm ⛬ᗘ䛷䛒䜚䠈᭱䜒ᑠ䛥䛔䜒䛾䛷 20nm

య᳨ฟჾ䛷䛒䜛䛯䜑䠈䛹䛖䛧䛶䜒ෆ㒊䛷䛾ከ㔜ᩓ஘䛜኱䛝䛔䛾⛬ᗘ䛾 Ultra-NIT (UNIT)䛜䛒䜛䚹䛷䛝䛯ங๣䛿䠈䝥䝷䝇䝏䝑䜽䜔䛸䠈⤖ᬗ䛻䜘䜛䝕䝆䝍䜲䝈䛻䜘䜛ᙳ㡪䛜୺せ䛺ᝏ໬ཎᅉ䛷䛿䛒䜺䝷䝇ᇶᯈ䛾ୖ䛻ሬᕸ䛥䜜䠈ᅗ 7䠄ᕥ䠅䛾䜘䛖䛺䇾䝣䜱䝹䝮”䛸䛧䛶䜛䚹୍᪉䛷䠈㟁㞳㟁Ꮚ䛿ᩘ 10nm 䛾ᒁᅾ䛧䛯㡿ᇦ䛷᏶⤖䛩䜛䛯౑⏝䛥䜜䜛䚹౛䛘䜀䠈NIT 䛻グ㘓䛥䜜䛯䃐⥺䛿䠈ᅗ 7䠄ྑ䠅䛾䜘䛖䜑䠈䛭䛾ศ䝗䝸䝣䝖䝏䝱䞁䝞䞊䛾䜘䛖䛺䝗䝸䝣䝖㛗䛻䜘䜛ᣑᩓ䛾ᙳ㡪䛜䛺䛔䚹䛴䜎䜚䠈䛣䛾 AgBr䠄I䠅⤖ᬗ䛻䛚䛡䜛㟁㞳㟁Ꮚ䛾ᒁᅾグ㘓⬟ຊ䛜䝕䝞䜲䝇䛾䝇䜿䞊䝷䞊䝡䝸䝔䜱䜢ಖド䛩䜛㔜せ䛺ᇶᮏཎ⌮䛷䛒䜛䚹

3.3 NIT ࡢ㔞Ꮚឤᗘ࡜᳨ฟຠ⋡᭱⤊ⓗ䛻䝕䝞䜲䝇䛜䛹䛾⛬ᗘ䛾㔞Ꮚឤᗘ䠄୍⤖ᬗ䛾཯ᛂ☜⋡䠅䛚䜘䜃㣕㊧᳨ฟຠ⋡䜢ᣢ䛴䛾䛛䛜ᐇ㝿䛾ᐇ㦂䝕䝄䜲䞁䛷ᅗ 7 ࣉࣛࢫࢳࢵࢡᇶᯈ࡟ሬᕸࡉࢀࡓ NIT ࣇ࢕࣒ࣝ㸦ᕥ㸧࠾ࡼࡧグ㘓ࡉࢀࡓȘ⥺ࡢ㣕㊧⩌ࡢⴠᑕᆺගᏛ㢧ᚤ㙾⏬ീ㸦ྑ㸧ࠋ䛿㔜せ䛺䛸䛣䜝䛷䛒䜛䚹䛣䜜䛻䛴䛔䛶䛿䠈⌧ᅾ䜒◊✲୰䛾㒊ศ䛜ከ䛔䛜䠈ᶆ‽䝕䝞䜲䝇䛻䛚䛡䜛ᛶ⬟䛻䛴䛔䛶䛿ᴫ䛽⌮ゎ䛜䛷䛝䛶䛔䜛䚹

ᅗ 8. NIT ࡟グ㘓ࡉࢀࡓప㏿Ⅳ⣲࢖࢜ࣥ㸦100keV㸧ࡢ㣕㊧ࡢ㟁Ꮚ㢧ᚤ㙾⏬ീࠋ⌧ീࡉࢀࡓ㖟ࡀࣇ࢕࣓ࣛࣥࢺᵓ㐀ࢆᣢࡗ࡚࠸ࡿࡢࡀࢃ࠿ࡿࠋᅗࡢ▮༳ࡣ㸪Ⅳ⣲࢖࢜ࣥࡢධᑕ᪉ྥࢆ⾲ࡋ࡚࠸ࡿࠋ

ᅗ 9 ⤖ᬗࢧ࢖ࢬศᕸ࠾ࡼࡧᐦᗘຠᯝࢆ⪃៖ࡋࡓࢩ࣑࣮ࣗࣞ
ࢩࣙࣥ࡟ࡼࡗ࡚ぢ✚ࡶࡽࢀࡿࢹࣂ࢖ࢫෆ㒊ࡢ㣕㊧㸦2 ⤖ᬗ௨ୖ㈏㏻㸧᳨ฟຠ⋡㸦ᕥᅗ㸧࠾ࡼࡧ 2 ḟඖゅᗘศゎ⬟㸦ྑᅗࠋ㟷
Ⅼ⥺ : ከ㔜ᩓ஘࡟ࡼࡗ࡚Ỵࡲࡿศゎ⬟, ㉥ᐇ⥺㸸ከ㔜ᩓ஘㸩⤖ᬗຠᯝ࡟ࡼࡿศゎ⬟㸧ࠋ䛻㠀ᖖ䛻䜽䝸䜰䛻᳨ฟ䛥䜜䜛䛣䛸䛜䛷䛝䜛䚹䜎䛯䠈䝃䝤䝭䜽䝻䞁⢏Ꮚ㣕㊧᳨ฟᛶ⬟䛿䠈䜲䜸䞁ὀධ⿦⨨䛷⾜䜟䜜䠈100keV 䛾ప㏿䜎䛪䠈ᐇ㝿䛾 AgBr(I)⤖ᬗ䛾㔞Ꮚឤᗘ䛿䠈㏻ᖖ⤖ᬗ䜢సᡂ䛧

Ⅳ⣲䜲䜸䞁䛻䛚䛔䛶䠈ᅗ 8 䛾㟁Ꮚ㢧ᚤ㙾⏬ീ䛷ぢ䜙䜜䜛䜘䛖䛺䛶䛭䛾䜎䜎䛾≧ែ䛷䛿㠀ᖖ䛻ప䛔䚹䛣䜜䛿䠈౛䛘䜀䠈䃐⥺䛜㈏㣕㊧᳨ฟ⬟䛜ᐇド䛥䜜䛶䛔䜛䚹㏻䛧䛯㝿䛷ゝ䛘䜀ᐇ⾜ⓗ䛻⣙ 20%⛬ᗘ䛷䛒䜛䚹䛣䛾㔞Ꮚឤᗘ䜢๻ⓗ䛻ୖ䛢䜛᪉ἲ䛜䠈䛔䜟䜖䜛䇾䝝䝻䝀䞁䜰䜽䝉䝥䝍䞊(HA)ቑឤ”䛸䛔䛖᪉ἲ䛷䛒䜚䠈䝕䝞䜲䝇䜢ⷧ䛔ள◲㓟䝘䝖䝸䜴䝮䛷ฎ⌮

3.2 NIT ࡢ✵㛫ศゎ⬟䝕䝞䜲䝇䛭䛾䜒䛾䛜ᣢ䛴✵㛫ศゎ⬟䛾ᐃ㔞ⓗ䛺⌮ゎ䛿䠈᳨䛩䜛䛣䛸䛻䜘䜚㔞Ꮚឤᗘ䛜ୖ᪼䛧䠈䜋䜌 100%䛸↓▩┪䛺㔞Ꮚឤฟჾ䛜ᣢ䛴ཎ⌮ⓗ䛺᳨ฟ㝈⏺䜢⌮ゎ䛩䜛ୖ䛷㔜せ䛷䛒䜛䚹䜎ᗘ䛜㐩ᡂ䛥䜜䜛䚹䛧䛛䜒䠈䛣䛾ቑឤἲ䛿⢏Ꮚ⥺䛻ᑐ䛧䛶䛾䜏ୖ

䛪䠈NIT 䛾⤖ᬗ䝃䜲䝈ศᕸ䛿䠈ᅗ 6 䛷♧䛩䜘䛖䛺ศᕸ䜢ᣢ䛴䛣᪼䛧䠈వศ䛺䝜䜲䝈䛾⏕ᡂ䛿୍ษ㉳䛣䜙䛺䛔䚹䛭䛾⌮⏤䛿䠈≉䛻ᐃ䛷䜟䛛䛳

NIT 䛾䜘䛖䛺㉸ᚤ⢏Ꮚ⤖ᬗ䛻䛚䛔䛶䛿 e-h 䛾෌⤖ྜ䛻䜘䜛₯ീ䛶䛚䜚䠈䛭䛣䛛䜙⤖ᬗయ✚඘ሸ⋡䛿 39 %䛷䛒䜛䛣䛸䛜ぢ✚䜒䜙᰾ᙧᡂຠ⋡䛾పୗ䛜୺せ䛺ప㔞Ꮚឤᗘ䛾せᅉ䛷䛒䜚䠈HA ቑ䜜䜛䚹䛣䜜䛿䠈40nm ⤖ᬗ䛾ሙྜ 1cm3 䛻~1016 ಶ䛾䝉䞁䝃䞊䛷ឤ䛿䠈୺䛻ṇᏍᤕ⋓䛻䜘䜚᭷ຠ㟁Ꮚᩘ䜢ቑ䜔䛩䛣䛸䜢┠ⓗ䛻䛧䛒䜛 AgBr䠄I䠅⤖ᬗ䛜඘ሸ䛥䜜䛶䛔䜛䛣䛸䛻䛺䜛䚹䝅䝭䝳䝺䞊䝅䝵䞁䛶䛔䜛䛛䜙䛷䛒䜛䠄ᐇ䛿䠈ள◲㓟䝘䝖䝸䜴䝮䛜᭷ຠ䛷䛒䜛䛣䛸䛿➹ୖ䛷䛣䛾⤖ᬗ䛾ศᩓᵓ㐀䜢㓄⨨䛧䠈䛭䛣䛻 SRIM ➼䛷Ⲵ㟁⢏Ꮚ⪅䛾⊂⮬Ⓨぢ䛷䛒䜚䠈෗┿⛉Ꮫ䛾ᴗ⏺䛷䛿ᮍ䛰ヲ⣽䛺䝯䜹䝙䝈

䛾㌶㐨䜢ィ⟬䛧䠈1 ⢏Ꮚ䛒䛯䜚 2 ಶ௨ୖ㈏㏻䛧䛯ሙྜ䜢䇾㣕㊧䝮䛿㆟ㄽ୰䛷䛒䜛䠅䚹䛭䛾㝿䛾୍⤖ᬗឤᗘ䛿䠈30keV 䛾Ⅳ⣲䜲䛸䠈䛥䜙䛻䠈䛭䛾ᐦᗘ䛿 3.3 g/cm3 䛷䛒䜛䛣䛸䛜┤᥋䠄track䠅䇿䛸ᐃ⩏䛧䛯ሙྜ䛾᳨ฟ⬟ຊ䜢㆟ㄽ䛧䛯䜒䛾䛜ᅗ 9 䛷䛒䜸䞁䛻䛚䛔䛶 100%䛸↓▩┪䛷䛒䜚䠈䛣䛾䛸䛝䛾㣕㊧᳨ฟຠ⋡䛸䜛䚹ᬯ㯮≀㉁᥈⣴䜢᝿ᐃ䛧䠈཯㊴ཎᏊ᰾ᶆⓗ䜢Ⅳ⣲䛸䛧䛯ሙྜ䛧䛶䛿 200nm 䛾᳨ฟ㜈್䜢௬ᐃ䛩䜛䛸䠈౛䛘䜀 100keV 䛾Ⅳ⣲

䛾㣕㊧᳨ฟ⬟ຊ䛸䛧䛶䛿䠈20keV 䛾Ⅳ⣲ཎᏊ᰾䛻䛚䛔䛶䜒䛻䛚䛔䛶䛿 80%䠈60keV 䛷䛿 40%⛬ᗘ䛸䛺䜛䚹㔞Ꮚឤᗘ䜢ྵ䜑䛯᳨ฟຠ⋡䛿䠈⤖ᬗ䛭䛾䜒䛾䛜ᣢ䛴₯ീ᰾ᙧᡂຠ⋡䛰䛡䛷䛿

4.2 Post Track Selector (PTS)

ͷͲͷ
21

䛺䛟䠈ඛ䛻䜒㏙䜉䛯䜘䛖䛺⌧ീάᛶ䛻䜒౫Ꮡ䛩䜛䚹⌧ᅾ 䛿䠈⌧ᅾ䠈䛣䛾⮬ືㄞ䜏ྲྀ䜚ἲ䜢䝧䞊䝇䛻㐠⏝䛧䛶䛔䜛䛾䛜ᅗ 9

MAA ⌧ീᾮ䛸䛔䛖 N 䝯䝏䝹䝟䝷䜰䝭䝜䝣䜵䝜䞊䝹◲㓟ሷ䛸䜰䝇䝁

䛾 PTS-2 䛷䛒䜚䠈ྠᵝ䛾䝅䝇䝔䝮䛷㧗㏿໬➼䛾㛤Ⓨ⏝ PTS-3 䜒䝹䝡䞁㓟䜢⌧ീ୺⸆䛸䛩䜛⌧ീᾮ䜢⮬䜙ฎ᪉䛧䛶⌧ീฎ⌮䛻䛩䛷䛻❧䛱ୖ䛜䛳䛶䛔䜛䚹䛥䜙䛻䠈䜲䝍䝸䜰䞉䝘䝫䝸኱Ꮫ䛻䜒ᵓ⠏⏝䛔䛶䛔䜛䚹䛣䛾㓟໬㑏ඖ㟁఩䛿−310mV ⛬ᗘ䛸䠈୍⯡ⓗ䛺෗䛥䜜㐠⏝䛥䜜䛶䛔䜛䛜䠈䝘䝫䝸኱Ꮫ䛾䝅䝇䝔䝮䛻䛚䛔䛶䛿ู䛾┿⌧ീᾮ䛸ྠ➼䛾䝺䝧䝹䛾䜒䛾䜢ᶆ‽䛻䛧䛶䛚䜚䠈䛛䛴ฎ⌮ゎᯒᡭἲ䜒ᑟධ䛥䜜䛶䛔䜛䛯䜑䠈䛭䜜䛻䛴䛔䛶䛿ᚋ㏙䛩䜛䚹ᗘ䜢㏻ᖖ 20䉝䛷⾜䛖䛸䛣䜝䜢 5䉝䜎䛷ୗ䛢䛶⾜䛳䛶䛔䜛䚹䛣䜜䛿䠈

PTS 䛿䠈㏻ᖖ䛿㏱㐣ᆺ䛾ගᏛ㢧ᚤ㙾䛜౑䜟䜜䜛䛾䛻ᑐ䛧䛶䠈⌧ീ䛻䜘䜛䝜䜲䝈䠄random fog䠅䛾άᛶ໬䜶䝛䝹䜼䞊䛸₯ീ᰾䛜ⴠᑕᆺ䛾ගᏛ㢧ᚤ㙾䛜⏝䛔䜙䜜䜛䚹ⴠᑕᆺ䛷䛿䠈ᅗ 10(ྑ)䛻ᣢ䛴άᛶ໬䜶䝛䝹䜼䞊䛾ᕪ䜢䜘䜚㢧ⴭ䛻䛩䜛䛯䜑䛷䛒䜚䠈⌧ീ䛒䜛䜘䛖䛺ᑐ≀䝺䞁䝈䛾ୖ㒊䛛䜙ග䜢ධᑕ䛧䠈፹య䛛䜙཯ᑕ䛥䜜཯ᛂ㏿ᗘ䛾ᗘ౫Ꮡᛶ䜢౑䛳䛶ప䝜䜲䝈໬䜢ᅗ䛳䛶䛔䜛䚹䛣䛾䜛ᩓ஘ග䜢⤖ീ䛧䠈ീ䜢ྲྀᚓ䛩䜛䚹ୖグ䛾ᴃ෇ゎᯒ䛿䠈䜘䜚▷ᕤኵ䛻䜘䜚䠈ᚑ᮶䛻ẚ䜉䛶 1/5 ௨ୗ⛬ᗘ䜎䛷䝜䜲䝈䝺䝧䝹䜢ᢚ䛘Ἴ㛗䛾ග䜢⏝䛔䜛䛣䛸䛷ീ䛾ゎീᗘ䠄㣕㊧䛾᳨ฟྍ⬟㜈್䠅䛜䛶䛔䜛䚹ᐇ㝿䛿䠈䛥䜙䛻ప䛔ᗘ䛷䜒≉ᛶ䜢ぢ䛯䛔䛜⌧ᅾ䛿ᐇྥୖ䛩䜛䛯䜑䠈䝞䞁䝗䝟䝇䝣䜱䝹䝍䞊䜢㏻䛧䛶 430㼼20nm 䛻㦂䛾ඃඛᗘ䛛䜙 5䉝䛷䛾ฎ⌮䜢ᶆ‽䛸䛧䛶㐍䜑䛶䛔䜛䚹ୖグ䛾⤠䛳䛯Ἴ㛗䜢⏝䛔䜛䚹᧜ീ⣔䛿 2 Mpix 䜎䛯䛿 4Mpix 䛾 CMOS᳨ฟຠ⋡䛿䠈䛣䛾䜘䛖䛺⌧ീฎ⌮ឤᗘ䜒ྵ䜑䛯䜒䛾䛷䛒䜚⌧ᅾ䜹䝯䝷䜢⏝䛔䛶᧜ീ䛩䜛䚹䝣䝺䞊䝮䝺䞊䝖䛿᭱኱ 300 fps ྍ⬟䛷䛾ᣦᶆ䛸䛺䛳䛶䛔䜛䚹⌧ീ䛥䜜䛯ಙྕ䛿䠈ගᏛ㢧ᚤ㙾䝧䞊䝇䛾䛒䜛䛜䠈ᐇ㝿䛾ග㔞䛸䛾ව䛽ྜ䛔䛷䠈⌧ᅾ䛿 150fps 䛷㐠⏝䜢ㄞ䜏ྲྀ䜚䝅䝇䝔䝮䛷ㄞ䜏ฟ䛥䜜ゎᯒ䛥䜜䜛䛣䛸䛻䛺䜛䚹᭱⤊ⓗ䛺⾜䛳䛶䛔䜛䚹䜎䛯䠈X, Y, Z 䛭䜜䛮䜜䛻䝇䝔䝑䝢䞁䜾䝰䞊䝍䞊䛻䜘᳨ฟຠ⋡䛿䠈䛣䛾㣕㊧䜢ㄞ䜏ฟ䛩䠄䛚䜘䜃㑅ู䛩䜛䠅ຠ⋡䜒ᙳ䜛㥑ື⣔䛜ᦚ㍕䛥䜜䛶䛚䜚䠈≉䛻䠈Z ᪉ྥ䠄⿕෗⏺᪉ྥ䠅䛻䛚䛔㡪䛧䛶䛟䜛䚹䛣䜜䛻䛴䛔䛶䛿ḟ䛾❶䛷⤂௓䛩䜛䚹䛶䛿䠈䛭䛾䝇䝔䝑䝥䛤䛸䛻᧜ീ䛩䜛䚹䛣䛾䝇䝔䝑䝥䛾᭱㐺໬䛿ᚲ

4. ࢧࣈ࣑ࢡࣟࣥ㣕㊧ࡢㄞࡳྲྀࡾᢏ⾡
4.1 ࢧࣈ࣑ࢡࣟࣥ⢏Ꮚ㣕㊧ゎᯒ㣕㊧䛾⮬ືゎᯒᢏ⾡䛿䠈ཎᏊ᰾஝ᯈ䛜⌧ᅾ䛷䜒◊✲⌧ሙ䛾➨୍⥺䛷౑䜟䜜䜛᭱䜒㔜せ䛺せᅉ䛷䛒䜛䚹౛䛘䜀䠈OPERA ᐇ㦂䛻䛚䛔䛶䛿䠈S-UTS 䛸࿧䜀䜜䜛⮬ື㧗㏿㣕㊧ㄞ䜏ྲྀ䜚⿦⨨[16]䛻䜘䜚⣙ 40 cm2/h 䛾㏿ᗘ䛷㣕㊧䝕䞊䝍䛾ㄞ䜏ྲྀ䜚(䝇䜻䝱䞁)䛜⾜䜟䜜䠈᭱㏆䛾᭱䜒᪩䛔䝅䝇䝔䝮 HTS[17] 䛻䛚䛔䛶䛿䛥䜙䛻ᅗ 10 ⌧ᅾ㐠⏝୰ࡢࢧࣈ࣑ࢡࣟࣥ㣕㊧⮬ືㄞࡳྲྀࡾ⏝ࢩࢫࢸ࣒䛭䛾 100 ಸ䛾㏿ᗘ䛷䝇䜻䝱䞁䛜⾜䜟䜜䛶䛔䜛䚹ᮏ◊✲䛻䛚䛔䛶

PTS.2 㸦ᕥᅗ:඲యീ,ྑᅗ㸸ㄞࡳྲྀࡾ୰ࡢᑐ≀ࣞࣥࢬ࠾ࡼࡧ

䜒౛እ䛺䛟⮬ືゎᯒ䝅䝇䝔䝮䛜ᚲせ䛻䛺䜛䛜䠈⌧ᅾ䛾䝅䝇䝔䝮

NIT ࣇ࢕࣒ࣝ㸧ࠋ䛿ཎᏊ᰾஝ᯈ䜢㈏㏻䛩䜛ᩘ༑ μm ௨ୖ䛾┤⥺ᛶ䛾㧗䛔㣕㊧䜢䛪䛧䜒༑ศ䛷䛿䛺䛔䛜䠈䝺䞁䝈䛾⌮ㄽ⿕෗⏺῝ᗘ 0.3μm 䜢⪃៖ᢳฟ䛩䜛䛣䛸䛻≉໬䛧䛯䜒䛾䛷䛒䜚䠈䛭䜒䛭䜒䝃䝤䝭䜽䝻䞁䛾⢏Ꮚ

䛧䠈80 䝇䝔䝑䝥/view 䛷᧜ീ䛩䜛䚹䛭䛣䛻Ꮡᅾ䛩䜛஦㇟䛾㍤ᗘ᝟

㣕㊧䜢ㄞ䜏ฟ䛩䛣䛸䛿୙ྍ⬟䛷䛒䜛䚹䛣䛾⮬ື䝕䞊䝍ྲྀᚓἲ䛾ሗ䛛䜙䝧䝇䝖䝣䜷䞊䜹䝇ᒙ䜢ᢳฟ䛩䜛䛣䛸䛷䠈ྛ஦㇟䛻䛚䛡䜛

㛤Ⓨ䛻㠀ᖖ䛻ከ䛟䛾᫬㛫䜢㈝䜔䛧䛯䚹䛭䛾኱䛝䛺⌮⏤䛿䠈30 ᖺ

XYZ 䛾 3 ḟඖ఩⨨᝟ሗ䜢ྲྀᚓ䛩䜛䛣䛸䛜䛷䛝䜛䚹PTS 䜢⏝䛔䜛௨ୖ⥆䛟⮬ືゎᯒ䛾᪉ἲㄽ䛾ᖖ㆑䛾ቨ䛷䛒䜚䠈䛭䛾ᛮ⪃䛛䜙䛾䛣䛸䛷䠈⮬ື䛷䛾஦㇟ゎᯒ䛜ྍ⬟䛻䛺䜚䠈䝕䝞䜲䝇䛻䛚䛡䜛ᐈ⬺༷䛿➹⪅䛾ຊ㔞䛾↓䛥䜒䛒䜚㧗䛔䝫䝔䞁䝅䝱䝹㞀ቨ䛜Ꮡᅾ䛧ほⓗ䛛䛴ᐃ㔞ⓗ䛺ホ౯䛜ྍ⬟䛻䛺䛳䛯䛣䛸䛿䠈䝕䝞䜲䝇㛤Ⓨ䛾䛯䛛䜙䛷䛒䜛䚹䛣䛣䛷ᥦ᱌䛧䛯䛾䛜ゝ䜟䜜䛶䜏䜜䜀㠀ᖖ䛻䝅䞁❧ሙ䛛䜙䜒㠀ᖖ䛻኱䛝䛺㐍ᒎ䛷䛒䜛䚹䝥䝹䛷䛒䜛䛜䠈䝃䝤䝭䜽䝻䞁䛾⢏Ꮚ㣕㊧䛜ᣢ䛴ගᏛീ䛾䜖䛜䜏䜢䝟䝷䝯䞊䝍໬䛩䜛䛣䛸䛷䛒䜚䠈䛣䜜䛿㔜ຊ䝺䞁䝈䛾ほ䛻㛵䛩஦㇟㑅ูἲ䛸䛧䛶䠈ඛ䛻㏙䜉䛯ᴃ෇䝟䝷䝯䞊䝍䜢⏝䛔䛯ሙྜ䠈
ᅗ 11 䛻♧䛩䜘䛖䛻ప㏿Ⅳ⣲䜲䜸䞁䛻ᑐ䛩䜛᪉ྥศᕸ䜢ྲྀᚓ䛩䜛䝉䝭䝘䞊䜢⫈ㅮ䛧䛶䛔䜛䛸䛝䛻䝠䞁䝖䜢ᚓ䛯䚹䛴䜎䜚䠈㛗䛔㣕㊧䠄䛣䛣䛷䛿 10μm ௨ୖ䠅䛻័䜜䛶䛔䜛䛸ぢ䛘䛺䛔䛾䛰䛜䠈ᙧ≧䛾ᚤጁ䛺ṍ䜏䛻↔Ⅼ䜢ᙜ䛶䛶䜏䜛䛸䠈ᴃ෇ᙧ≧䜢ᣢ䛴⢏Ꮚ䛜䠈᪉ྥ䛜ᥞ䛳䛶୪䜣䛷䛔䜛䛾䛜ほ䛘䜛䜘䛖䛻䛺䛳䛯䠄䛭䜜䜎䛷඲䛟Ẽ௜䛛䛺䛛䛳䛯䛜䠈୍ᗘほ᪉䜢ぬ䛘䜛䛸୙ᛮ㆟䛸Ⰽ䚻䛺䜒䛾䛜ほ䛘䛶䛟䜛䠅䚹䜎䛪䛿䝅䞁䝥䝹䛺ᴃ෇ᙧ≧ゎᯒ䛷ᴃ෇䝣䜱䝑䝖䛧䠈䛭䛾㛗㍈᪉ྥศᕸ䜢ྲྀ䜛䛸䠈ぢ஦䛻䜲䜸䞁䛾ධᑕ᪉ྥ䛻ᥞ䛳䛯᪉ྥศᕸ䜢᳨ฟ䛩䜛䛣䛸䛜䛷䛝[18]䠈䛣䛾ᡭἲ䜢䝧䞊䝇䛻䠈ᙜ᫬䛾

ᅗ 11

PTS 䛻䜘䛳䛶ㄞ䜏ฟ䛥䜜䛯 60keV 䛾Ⅳ⣲䜲䜸䞁䛻䛚䛡኱Ꮫ㝔⏕䛾ྜྷᮏ䠈᱇ᕝ䜙䛸᪂䛧䛔⮬ືゎᯒ䝅䝇䝔䝮䠄Post Track䜛㻌 (a)ගᏛ⏬ീ䝕䞊䝍䠄⦪᪉ྥ䛻ᴃ෇ᙧ≧䛾㣕㊧䛜ぢ䛘䜛䠅,

Selector: PTS䠅[19]䛾ᵓ⠏䜢㐍䜑䜛䛣䛸䛻䛺䛳䛯䚹䛚䜘䜃(b) ᴃ෇ᙧ≧ゎᯒ䛻䜘䜛㛗㍈᪉ྥ 2 ḟඖゅᗘศᕸ䚹

ͷͲ͸
22

䜛䛣䛸䛜ྍ⬟䛷䛒䜛䚹䛣䛾᫬䛾᳨ฟྍ⬟䛺㣕⛬䛾㜈್䛿䠈⤖ᬗศᴟ䛸䛾䝬䝑䝏䞁䜾䛾䛯䜑፹㉁䛾ㄏ㟁⋡䛻䜒౫Ꮡ䛩䜛䠅䚹≉䛻䠈䛻䜘䜛ᙳ㡪䜢௜ຍ䛧䛯䝅䝭䝳䝺䞊䝅䝵䞁䛸䛾ẚ㍑䛻䜘䜚䠈⣙ 196nm

㔠䜔㖟䛸䛔䛖䛾䛿䛣䛾ඹ㬆Ἴ㛗䛜ྍどග㡿ᇦ䛻Ꮡᅾ䛩䜛䛯䜑䠈䛸ホ౯䛥䜜䛶䛚䜚䠈䛣䜜䛿ᖹᆒ㣕⛬䛷䛔䛘䜀Ⅳ⣲཯㊴䛻䛧䛶䛥䜎䛦䜎䛺㟁Ꮚ≀ᛶ䛻䛚䛡䜛◊✲ᑐ㇟䛸䛺䛳䛶䛔䜛䚹

50keV 䛾᳨ฟ㜈್䛻┦ᙜ䛩䜛䚹䜎䛯䠈ゅᗘศゎ⬟䛿⣙ 30㼻䛷

NIT 䛻䛚䛡䜛⌧ീ㖟䛿䠈ᅗ 8 䛷ぢ䜛䜘䛖䛻ᩘ༑ nm 䛾ᵓ㐀䜢䛒䜛䚹ᴃ෇ゎᯒ䛾୍␒䛾┠ⓗ䛿䠈୍✀䛾䝎䞊䜽䝜䜲䝈䛷䛒䜛䠈䛔ᣢ䛴䠈䛔䜟䜖䜛㖟䝘䝜⢏Ꮚ䛷䛒䜛䛣䛸䛛䜙䠈LSPR 䛜ྍどගᇦ䛷䜟䜖䜛䇾random fog”䛸ೃ⿵஦㇟䛸䛾ษ䜚ศ䛡䛻䛒䜛䚹ᐇ㝿䠈ཎᏊㄏ㉳䛥䜜䜛䚹⌧ᅾ䠈ⴠᑕගᏛ㢧ᚤ㙾䜢౑䛖⌮⏤䛿䠈䛣䛾 LSPR

᰾஝ᯈ䛿䛣䛾 random fog 䛸䛔䛖䛾䛜Ⓨ⏕䛧䛶䛧䜎䛖䚹䛭䛾ཎᅉ䛿䛾ຠᯝ䜢ㄏⓎ䛧䝁䞁䝖䝷䝇䝖䛻཯ᫎ䛥䛫䜛䛣䛸䛷䜒䛒䜛䚹䛔䛟䛴䛛䛒䜚䠈NIT 䛾ሙྜ䠈✚ᴟⓗ䛺 fog ⏕ᡂ䜢㉳䛣䛩໬Ꮫฎ

LSPR 䛻䛚䛡䜛ඹ㬆Ἴ㛗䛿䠈㖟䝘䝜⢏Ꮚ䛻䛚䛡䜛䝃䜲䝈䜔ᙧ⌮䛿⾜䛳䛶䛔䛺䛔䛯䜑䠈ఱ䜙䛛䛾⇕ⓗ⏕ᡂ䝥䝻䝉䝇䛰䛸ᛮ䜟䜜≧䛻ᙉ䛟౫Ꮡ䛩䜛䚹౛䛘䜀䠈ᅗ 12 䛻♧䛩䜘䛖䛻䠈㖟䝘䝜⢏Ꮚ䛾䜛䛜䛭䛾᰿ᮏⓗཎᅉ䛿䜘䛟䜟䛛䛳䛶䛔䛺䛔䚹䛧䛛䛧䠈䛣䛖䛔䛳䛯䝜䝃䜲䝈䛻౫Ꮡ䛧䛶ඹ㬆Ἴ㛗䛜䝅䝣䝖䛧䛶䛔䜛䛣䛸䛜䜏䛶䛸䜜䜛䚹䜲䝈䛿 single grain 䛷ᵓᡂ䛥䜜䜛䜒䛾䛜䜋䛸䜣䛹䛷䛒䜛䛯䜑䠈ᴃ䜎䛯䠈ᙧ≧䜢ᣢ䛳䛯㖟䝘䝜⢏Ꮚ䠈౛䛘䜀䝻䝑䝗≧䛾䜒䛾䛰䛸䠈┤෇䝟䝷䝯䞊䝍䛾㜈್タᐃ䛻䜘䛳䛶⣙ 4 ᱆䛾㝖ཤ䜢⾜䛳䛶䛚䜚䠈⥺೫ග䛧䛯ග䜢ධᑕ䛩䜛䛸䠈䛭䛾೫ග᪉ྥ䛸䝻䝑䝗䛾㛗㍈᪉ྥᐇ㦂䛻䛚䛔䛶⮴࿨ⓗ䛺ၥ㢟䛻䛿䛺䜙䛺䛔䚹䛯䛰䛧䠈䛹䛖䛧䛶䜒䝔䛜୪⾜䛾ሙྜ䛿㛗Ἴ㛗䛻䠈ᆶ┤䛾ሙྜ䛿▷Ἴ㛗䛻䝅䝣䝖䛩䜛䚹䜲䝹䛿ṧ䛳䛶䛝䛶䛧䜎䛔䠈㜈್䛻ไ㝈䛜⏕䛨䜛䛜䠈䛣䜜䛿⏬ീྲྀᚓ䛾㝿䛾᣺ື䛻䜘䜛ᚤጁ䛺᧜ീ᫬䛾䜖䛜䜏䛾ᙳ㡪䛸䛧䛶⪃䛘䜙䜜䜛䛯䜑䠈䛥䜙䛻ప㜈್໬䜢≺䛖ሙྜ䛿䠈䝕䞊䝍ྲྀᚓ୰䛾᣺ືᑐ⟇䜢༑ศ䛻⾜䛖ᚲせ䛜䛒䜛䚹 䛯䛰䛧䠈 䛣䛖䛔䛳䛯஦㇟䛿 䠈
accidental 䛺ᰁ䜏ฟ䛧䛷䛒䜛䛾䛷䠈2 ḟゎᯒ䛷᏶඲䛻㝖ཤ䛥䜜䜛䛯䜑ᮏ㉁ⓗ䛺⫼ᬒ஦㇟䛻䛿䛺䜙䛺䛔䚹䛭䜜䛷䛿༑ศ䛺䝞䝑䜽䜾䝷䜴䞁䝗㝖ཤ䛻䛺䜛䛛䛸䛔䛖䛸䛭䛖䛷䛿䛺䛟䠈䜔䛿䜚ᴃ෇ᙧ≧䛰䛡䛷䛿㝈⏺䛜䛒䜛䚹䛭䛾⌮⏤䛿䠈䜔䛿䜚䛣䛾ᡭἲ䛿䛒䛟䜎䛷ගᏛᅗ 12 㖟䝘䝜⢏Ꮚ䛾 LSPR 䛻䜘䜛ගᏛീ䚹ᕥ䛛䜙 40, 80, 120nm 䛾㖟䝘䝜⢏Ꮚ䛷䛒䜚,䛭䜜䛮䜜ඹ㬆Ἴ㛗䛜㟷,⥳,㉥䛸䝅䝣䝖䛧䛶䛔䜛䚹ศゎ⬟䛻ไ㝈䛥䜜䛯ゎᯒ䛷䛒䜚䠈 ගᏛศゎ⬟䜘䜚䜒ᑠ䛥䛔㡿ᇦᡃ䚻䛿䠈䛣䛾೫ග᪉ྥ䛻౫Ꮡ䛧䛯ඹ㬆Ἴ㛗䝅䝣䝖䜢䛖䜎䛟౑䛖䛣䛾᝟ሗ䛿ྲྀᚓ䛷䛝䛺䛔䛯䜑䛷䛒䜛䚹୍᪉䠈2.2 䛷㏙䜉䛯䛸䛚䜚䠈䛸䛻䜘䛳䛶ගᏛศゎ⬟䜘䜚䜒ᑠ䛥䛔ᵓ㐀䛾᝟ሗྲྀᚓ䛜ྍ⬟䛺䝅⌧ീ㖟䛾᝟ሗ䛿 0/1 䛷䛿䛺䛟䠈䝘䝜䝇䜿䞊䝹䛾㡿ᇦ䛻Ⲵ㟁⢏Ꮚ䝇䝔䝮䛚䜘䜃ゎᯒἲ䛻䛴䛔䛶㛤Ⓨ䜢⾜䛳䛶䛝䛯䚹䛾 dE/dx 䜒䛧䛟䛿እ㒊䛛䜙ΰධ䛧䛯୙⣧≀➼䛾᝟ሗ䛜ྵ䜎䜜䜛䚹䛭䛾୍䛴䛜㉸ゎീゎᯒἲ䛷䛒䜛䚹㉸ゎീゎᯒἲ䛿䠈2014 ᖺ౛䛘䜀䠈ᅗ 8 䛾䜘䛖䛺䛿㟁Ꮚ㢧ᚤ㙾䛷ほᐹ䛧䛯⢏Ꮚ㣕㊧䛿䠈㠀䛾䝜䞊䝧䝹໬Ꮫ㈹䛾ཷ㈹䝔䞊䝬[21] 䛸䛺䛳䛶䛚䜚䠈㢧ᚤἲᢏᖖ䛻ᐦ䛺㖟⢏Ꮚ䛻䛚䛡䜛䝣䜱䝷䝯䞁䝖ᵓ㐀䜢ᣢ䛴䚹䛣䜜䛿Ⲵ㟁⢏⾡䛻䛚䛡䜛㔜せ䛺䝤䝺䞊䜽䝇䝹䞊䛸䛺䛳䛯䚹䛣䛾ᇶᮏ䝁䞁䝉䝥䝖Ꮚ䛻䜘䜛₯ീ᰾ᙧᡂ䛸䛔䛖䝥䝻䝉䝇䛻䛚䛡䜛ᴟ䜑䛶䝴䝙䞊䜽䛺䛿௨ୗ䛾䛸䛚䜚䛷䛒䜛䚹ᮏ᮶䠈ගᏛศゎ⬟䛿䝺䜲䝸䞊䛾ᅇᢡ㝈᝟ሗ䛷䛒䜚䠈䛣䛾᝟ሗ䜢䛔䛛䛻ගᏛ㢧ᚤ㙾䛛䜙ྲྀ䜚ฟ䛩䛛䛜௒⏺䛷▱䜙䜜䜛䜘䛖䛻 2 Ⅼ䜢ศゎ䛷䛝䜛⬟ຊ䛷䛒䜛䚹㏻ᖖ䛾ගᏛᚋ䛾䝞䝑䜽䜾䝷䞁䝗㝖ཤ䛾䜻䞊䝫䜲䞁䝖䛷䛒䜛䠄㟁Ꮚ㢧ᚤ㙾䛷ほ㢧ᚤ㙾䛻䛚䛔䛶䛿䠈Ἴ㛗䛸ᑐ≀䝺䞁䝈䛾㛤ཱྀᩘ䠄Numerical Ap-ᐹ䛷䛝䜜䜀䛩䜉䛶ゎỴ䛷䛒䜛䛜䠈⌧ᅾ䛾䝔䜽䝜䝻䝆䞊䛷䛿ほᐹ

erture: N.A.䠅䛻౫Ꮡ䛧䠈Ἴ㛗 450nm䠈N.A. 1.45 䛷⣙ 200nm ⛬㠃✚䜔䝃䞁䝥䝹ᙧ≧䛾ᙉ䛔ไ㝈䛛䜙ᐇ⏝ⓗ䛻ᅔ㞴䛷䛒䜛䠅䚹⌧ᗘ䛷䛒䜛䚹䛣䛣䛻䛿㔜せ䛺኱๓ᥦ䛜䛒䜚䠈䛭䜜䛿䇾2 Ⅼ䜢ྠ᫬䛻ᅾ䛾㛤Ⓨ䝔䞊䝬䛸䛧䛶䠈1 ḟ㑅ู䠄ᴃ෇ᙧ≧ゎᯒ䠅䛻䜘䛳䛶䝖䝸䜺䞊䛥䜜䛯ೃ⿵஦㇟䛻䛴䛔䛶䠈 䛥䜙䛻ගᏛ㢧ᚤ㙾䜢⏝䛔䛶ගᏛศゎ⬟௨ୖ䛾᝟ሗ䜢ྲྀ䜚ฟ䛩䛣䛸䜢୺┠ⓗ䛻㛤Ⓨ䜢㐍䜑䛶䛔䜛䚹䛭䛾᭷ຊ䛺᪉ἲ䛾୍䛴䛸䛧䛶ᒁᅾ⾲㠃䝥䝷䝈䝰䞁ඹ㬆
䠄Localized Surface Plasmon Resonance : LSPR䠅[20] 䛸࿧䜀䜜䜛ගᏛᛂ⟅䜢㥑౑䛧䛯ゎᯒᢏ⾡䛾◊✲䜢⾜䛳䛶䛚䜚䠈ḟ䛻⤂௓䛩䜛䚹

4.3 LSPR ࡟ࡼࡿ஦㇟ゎᯒᒁᅾ⾲㠃䝥䝷䝈䝰䞁ඹ㬆䠄LSPR䠅䛿䠈Ἴ㛗䜘䜚䜒ᑠ䛥䛔㔠ᒓ䝘䝜⢏Ꮚ≉᭷䛾ගᏛᛂ⟅䛷䛒䜛䚹ヲ䛧䛔⌮ㄽ䛿[20]䜢ཧ↷䛧䛶䛔䛯䛰䛡䜜䜀䜘䛔䛜䠈⡆༢䛻ゝ䛘䜀㔠ᒓ䝘䝜⢏Ꮚ୰䛾⮬⏤㟁Ꮚ䛜㟁☢ሙ䛻䜘䛳䛶㞟ᅋⓗ䛺ศᴟ᣺ື䛧䛯㝿䛾ඹ㬆⌧㇟䛷䛒䜚䠈㔠ᒓ䝘䝜⢏Ꮚ䛾ศᴟ⋡䠄ㄏ㟁⋡䠅䛸䝥䝷䝈䝬᣺ືᩘ䛻䜘䛳䛶䛭䛾྾཰䜎䛯䛿ᩓ஘䛻ᑐ䛩䜛ඹ㬆Ἴ㛗䛜Ỵ䜎䜛䠄࿘㎶፹㉁䛾

ᅗ 13 ప㏿Ⅳ⣲䜲䜸䞁䛻䛚䛡䜛 LSPR 䛻䜘䜛೫ග౫Ꮡᛶ䛻ᑐ䛩䜛ගᏛീ䚹䠄ᕥᅗ䠅䛚䜘䜃䛭䜜䛮䜜䛾೫ගゅ䛤䛸䛾ീ䛾㔜ᚰ఩⨨䛾
XY ศᕸ䠄ྑᅗ䠅䚹䛭䜜䛮䜜䛾㔜ᚰỴᐃ⢭ᗘ䛜 10nm 䛷䛒䜚, 䜘䜚ヲ⣽䛺㣕㊧᪉ྥ䛸ෆ㒊᝟ሗ䜢ྲྀᚓ䛷䛝䛶䛔䜛䚹

ͷͲ͹
23

ぢ䛯䛸䛝䇿䛸䛔䛖䛣䛸䛷䛒䜛䚹㏫䛻ゝ䛘䜀䠈2 Ⅼ䜢ู䚻䛻ぢ䜜䜀䛭䛾㝈䜚䛷䛿䛺䛔䛣䛸䜢ព࿡䛧䠈䛣䜜䜢ᐇ㝿䛻⺯ගⰍ⣲䛻䜘䜛Ⓨග≉ᛶ䜢⏝䛔䛶㉸ゎീ㢧ᚤἲ䛜ᐇ⌧䛥䜜䛶䛔䜛䚹䛣䜜䜢䝠䞁䝖䛻䠈
LSPR ᛂ⟅䜢⏝䛔䛶㉸ゎീ䜢ᐇ⌧䛥䛫䜛䛸䛔䛖䛾䛜ᡃ䚻䛾䝁䞁䝉䝥䝖䛷䛒䜛䚹౛䛘䜀䠈ᙧ≧䛾␗䛺䜛㖟䝘䝜⢏Ꮚ䛜୪䜣䛷䛔䛯ሙྜ䠈ධᑕග䛻䛚䛡䜛೫ග᪉ྥ䜢ኚ䛘䠈䛛䛴Ἴ㛗䝣䜱䝹䝍䞊䜢⏝䛔䛶ほᐹ䛩䜛Ἴ㛗䜢ไ㝈䛧䛯ሙྜ䠈೫ග᪉ྥ䛻ᛂ䛨䛶䛹䛱䜙䛛୍᪉䛜ᙉ䛟ほᐹ䛥䜜䜛䝍䜲䝭䞁䜾䛜䛒䜛䚹䛴䜎䜚䠈∦᪉䜢ู䚻䛻ග䜙䛩䛣䛸䛜䛷䛝䜛䚹⤖ᯝ䠈ศゎ⬟䛿஦㇟䛾఩⨨Ỵᐃ⢭ᗘ䛷Ỵ䜎䜚 10nm ⛬ᗘ䜒䛧䛟䛿䛭䜜௨ୗ䜢㐩ᡂ䛩䜛䛣䛸䛜ྍ⬟䛷䛒䜛䚹䛣䛾ཎ⌮䛾ᐇド䛿䠈ᱵᮏ䜙䛾ㄽᩥ[22]䛻䜎䛸䜑䜙䜜䛶䛚䜚䠈ᅗ
12 䛾䜘䛖䛻䠈100nm ⛬ᗘ䛾㣕㊧䛻䛴䛔䛶䜒䛭䛾᪉ྥ䜢ྲྀ䜚ฟ䛩

ᅗ 15 ᅗ 14 䛾䝅䝇䝔䝮䛷ྲྀᚓ䛧䛯ప㏿Ⅳ⣲䜲䜸䞁䛾 LSPR 䛻䜘䜛೫ග౫Ꮡᛶ䝕䞊䝍䛾౛䚹䛭䜜䛮䜜䛾೫ගゅ䠄ᕥୗᩘ್䠅䛻ᑐ䛩䜛ගᏛ⏬ീ䝕䞊䝍䜢⮬ືྲྀᚓྍ⬟䛷䛒䜛䛣䛸䛻ᡂຌ䛧䛯䚹䛣䛾ᐇド◊✲䜢䜒䛸䛻䠈⌧ᅾ䠈LSPR ᝟ሗ䜢㥑౑䛧䛯ᅗ 14 䛾䜘䛖䛺⮬ືゎᯒ䝅䝇䝔䝮䜢䝘䝫䝸኱Ꮫ䛻䛶㛤Ⓨ䜢䜜䜛ணᐃ䛷䛒䜚䠈ೃ⿵஦㇟䛾Ỵᐃ⢭ᗘ䠄⫼ᬒ஦㇟䛸䛾㆑ู⬟䠅㐍䜑䛴䛴㐠⏝䜒㛤ጞ䛧䛶䛔䜛[23]䚹䛣䜜䜎䛷䝯䜹䝙䜹䝹䛻ᅇ䛧䛶ྥୖ䜢ẁ㝵ⓗ䛻ྥୖ䛥䛫䛶䛔䛟䚹䛔䛯೫ගᯈ䜢䠈ᮏ⿦⨨䛷䛿ᾮᬗศᏊ䛾㓄ྥ᪉ྥ䜢䝞䜲䜰䝇㟁ᅽ䛻䜘䛳䛶䝁䞁䝖䝻䞊䝹䛩䜛ᾮᬗ೫ග䝻䞊䝔䞊䝍䜢ᑟධ䛧䛯䚹䛣

5. ⫼ᬒ஦㇟ࡢ⌮ゎ䜜䛻䜘䜚䠈䝯䜹䝙䜹䝹䛺᣺ື䜢ᢚ䛘䛯ගᏛ⣔䜢᥇⏝䛧䠈೫ගゅ䛤ୖグ䛷⤂௓䛧䛯䜘䛖䛺䛥䜎䛦䜎䛺ゎᯒᢏ⾡䛾㛤Ⓨ䛻䜘䜚䠈᳨ド䛸䛾஦㇟⏬ീ䝕䞊䝍䜢ᅗ 15 䛾䜘䛖䛻ྲྀᚓ䛷䛝䠈䛭䛾ᙧ≧䜔㍤ᗘ

䛻ᚲせ䛺䝕䞊䝍䛾ྲྀᚓ䛜ྍ⬟䛸䛺䜚䠈䛭䜜䛻క䛔䠈⫼ᬒ஦㇟䛸㔜ᚰ఩⨨➼䛾䝟䝷䝯䞊䝍౑䛳䛶஦㇟ゎᯒ䜢⾜䛖䚹䛣䛾䝅䝇䝔䝮䛻䛭䛾ཎᅉ䜢⌮ゎ䛧䠈䛭䛾๐ῶ䛻ྲྀ䜚⤌䜐䛸䛔䛖䝣䜵䞊䝈䛻ධ䛳䛶䛚䛡䜛ศゎ⬟䛿 5nm 䜢㐩ᡂ䛧䛶䛚䜚䠈㣕㊧᳨ฟྍ⬟䛺㜈್䛿䛔䜛䚹

100nm 䜎䛷ୗ䛢䜛䛣䛸䛜䛷䛝䛯䚹䜎䛪䠈ෆ㒊䛾ᨺᑕᛶྠ఩య䛿䠈䛭䛾ᔂቯ䛻䜘䜛䃑⥺䛜⫼ᬒ஦㇟䜢స䜚ᚓ䜛䛯䜑⌮ゎ䛜ᚲせ䛷䛒䜛䚹䛭䛾Ꮡᅾ㔞䛿 ICP-MS䛚䜘䜃 Ge ᳨ฟჾ䜢⏝䛔䛶ホ౯䜢⾜䛳䛶䛝䛯䚹⤖ㄽ䛛䜙ゝ䛖䛸ᚑ᮶䛾䜒䛾䛿䠈K-40 䛜⣙ 70,000 mBq/kg 䜒Ꮡᅾ䛧䛶䛚䜚䠈᭱䜒㧗䛔ᨺᑕ⬟䜢ᣢ䛴ྠ఩య䛷䛒䛳䛯䚹䛣䛾୺䛺ཎᅉ䛿䠈䝝䝻䝀䞁໬㖟⤖ᬗ䜢⏕ᡂ䛥䛫䜛䛸䛝䛻⏝䛔䜛 KBr 䛾ṧ␃≀䛷䛒䜛䚹䛣䜜䛿䠈
NaBr 䜢⏝䛔䛶䜒ྠᵝ䛾⤖ᬗᡂ㛗䛜䛷䛝䜛䛣䛸䛛 KBr 䛾௦䜟䜚䛻
NaBr 䜢⏝䛔䜛䛣䛸䛷䠈K-40 䛾ྵ᭷㔞䜢 1/2000 ⛬ᗘ䛻๐ῶ䛩䜛䛣䛸䛻ᡂຌ䛧䛯䚹䝊䝷䝏䞁䜒௨๓䛻౑䛳䛶䛔䛯䜒䛾䛷䛿䛺䛟䠈⬺䜲䜸䞁໬䛧䛯㧗⣧ᗘ䝊䝷䝏䞁䜢⏝䛔䜛䛣䛸䛷 K-40 䛜 1/100 ௨ୗᅗ 14 䜲䝍䝸䜰䞉䝘䝫䝸኱Ꮫ䛻タ⨨䛥䜜䛶䛔䜛 LSPR ㉸ゎീゎᯒ⏝⮬ືゎᯒ䝅䝇䝔䝮䚹᧜ീ⣔䛾๓䛻ᾮᬗ೫ග䝻䞊䝔䞊䝍䞊䜢タ⨨䛩䜛䛣䛸䛷,ᅗ 10 䛾᝟ሗ䜢⮬ື䛷ྲྀᚓ䛩䜛䛣䛸䛜䛷䛝䜛䚹䛻పῶ䛧䛶䛔䜛䚹᭱⤊ⓗ䛻 Th䠈U 䛻䛴䛔䛶䛿ୖグ䛾ኚ᭦䛻䛿౫Ꮡ䛫䛪䠈10-20 mBq/kg ⛬ᗘ䛷䛒䜛䚹⌧ᅾ䠈᭱䜒኱䛝䛺ᨺᑕ⬟䝺䝧䝹䜢ᣢ䛴ྠ఩య䛿 C-14 䛷䛒䜚䠈Accelerator Mass Spectrometry (AMS) 䛾ᐃ䛻䜘䛳䛶 24,000 mBq/kg 䛸ホ౯䛧䛯䚹䛣䜶䝛䝹䜼䞊㜈್䛷ゝ䛘䜀 30 keV 䛾Ⅳ⣲཯㊴䛻䛴䛔䛶䜒᪉䜜䜙䛾㟁Ꮚ䝞䝑䜽䜾䝷䞁䝗䛻ᑐ䛧䛶䛿䠈NIT 䛻䛚䛡䜛 AgBr(I)䛾

ྥឤᗘ䜢ฟ䛫䜛䜘䛖䛻䛺䛳䛯䛣䛸䜢ព࿡䛧䛶䛚䜚䠈ᶆ‽ⓗ䛺ᬯ㯮ప㏿Ⅳ⣲䜲䜸䞁䛻ᑐ䛩䜛㔞Ꮚឤᗘ䛜䜎䛰㣬࿴䛧䛶䛔䜛≧ែ䛷≀㉁᥈⣴䛻䛚䛡䜛᥈⣴ྍ⬟䛺᩿㠃✚䛜 20 GeV/c2 䛾㉁㔞䛷 10䛒䜛䛯䜑䠈⤖ᬗ䛾㔞Ꮚឤᗘ䜢䛥䜙䛻ୗ䛢䠈䛥䜙䛻పಸ䛾ឤᗘྥୖ䛜ྍ⬟䛷䛒䜛䛣䛸䜢ព࿡䛧䛶䛔䜛䚹䛷ษ䜚ศ䛡䛜๻ⓗ䛻䜘䛟䛺䜛䛣䛸䛜䜟䛛䛳䛶䛔䜛[24]䚹㻌 ௒ᚋ䛿䛻䛩䜛䛣䛸䜎䛯䠈LSPR ㉳ᅉ䛾ᩓ஘ග䝇䝨䜽䝖䝹᝟ሗ䜢⏝䛔䜛䛣䛸䛷䛾஦ᐇ㦂䛻༶䛧䛯㍑ṇ䜢⾜䛔䛺䛜䜙㔞Ꮚឤᗘ䜢 3 ᱆௨ୖⴠ䛸䛩䛣䛸㇟㑅ู䜢䠈ᶵᲔᏛ⩦䜢⏝䛔䛶⾜䛖䛣䛸䜒㆟ㄽ䛥䜜䛶䛔䜛䚹ඛ䛻䜒䛷ᐇ㉁ⓗ䛻୙ឤ䛻䛩䜛䠈䜒䛧䛟䛿₯ീ᰾䛾 dE/dx ౫Ꮡᛶ䜢

㏙䜉䛯䜘䛖䛻䠈LSPR 䛿䝘䝜䝇䜿䞊䝹䛾ᵓ㐀䜢཯ᫎ䛧䛯ඹ㬆䝇䝨

LSPR 䛾䜘䛖䛺ゎᯒ䛻䜘䛳䛶ྲྀᚓ䛩䜛䛣䛸䛷㆑ู䛩䜛䛣䛸䜢┠ᣦ䜽䝖䝹䜢ᣢ䛴䚹䛣䛾ᵓ㐀䛜Ⲵ㟁⢏Ꮚ✀䠄dE/dx䠅➼䛻౫Ꮡ䛧䛶䛔䛧䛶䛔䜛䚹C-14 䜢㝖ཤ䛩䜛᪉ἲ䛸䛧䛶䛿䠈ேᕤ㧗ศᏊ䜢⏝䛔䜛䜜䜀䠈䝇䝨䜽䝖䝹᝟ሗ䛿⢏Ꮚ㆑ู䜔䝜䜲䝈㆑ู䛾㔜せ䛺᝟ሗ䛸䛣䛸䛜ᣲ䛢䜙䜜䜛䚹䛣䜜䛻䛴䛔䛶䜒ホ౯䜢㐍䜑䛶䛚䜚䠈௒ᚋ䛾ೃ䛺䜛䚹⌧ᅾ䠈䝙䝳䞊䝷䝹䝛䝑䝖䝽䞊䜽➼䜢⏝䛔䛶Ἴ㛗䝇䝨䜽䝖䝹䜔⿵䛸䛧䛶᭷ຊ䛺ேᕤ㧗ศᏊ䠄ヲ⣽䛿බ㛤䛷䛝䛺䛔䠅䛻䛚䛔䛶䠈ᙧ≧᝟ሗ➼䜒ྵ䜑䛯ᶵᲔᏛ⩦◊✲䜒㐍䜑䛶䛔䜛䚹⌧≧Ⰽ䚻䛸ᐃ㝈⏺௨ୗ(< 100 mBq/kg)䜎䛷ῶᑡ䛧䛶䛔䜛䛣䛸䛜᫂䜙䛛䛻⌮ゎ䛩䜉䛝Ⅼ䛜䛒䜛䛜䠈௒ᚋ䛾ゎᯒ䝣䝻䞊䛾୍㒊䛸䛧䛶ᐇ⿦䛥䛺䛳䛯䚹ᐇ㝿䠈Borexino ᐇ㦂䛻䛚䛔䛶౑䜟䜜䛶䛔䜛ᾮయ䝅䞁䝏

ͷͲͺ
24

䝺䞊䝍䛻䛚䛔䛶䛿⮬↛ྠ఩యẚ䛛䜙 7 ᱆௨ୖప䛔䛸䛔䛖ሗ࿌䜒䜻䝳䝸䝔䜱䛜㠀ᖖ䛻ཝ䛧䛟䛺䛳䛶䛧䜎䛔䠄᯾ᐇ㦂䛻䜘䜛ᾮయ䝅䞁䝏䛒䜛䛯䜑[25]䠈䛭䛖䛔䛳䛯పᨺᑕ⬟፹㉁䜢⏝䛔䛯䝕䝞䜲䝇㛤Ⓨ䜒䝺䞊䝍䛾₃ὤ䝖䝷䝤䝹䛜ཎᅉ䛾䜘䛖䛷䛒䜛䠅䠈ᡃ䚻䛾ᐇ㦂⎔ቃ䛾௒ᚋ㔜せ䛷䛒䜛䚹䜎䛯䠈䝕䝞䜲䝇ෆ㒊䛻 Th䞉U 䛜Ꮡᅾ䛩䜛ሙྜ䠈ᵓ⠏᫬ᮇ䛜䠈䛱䜗䛖䛹䛣䛖䛔䛳䛯䝉䜻䝳䝸䝔䜱ᙉ໬䛾⛣⾜ᮇ䛸䛔䛖(䃐䠈n)཯ᛂ䛻䜘䜛୰ᛶᏊ䛜⏕ᡂ䛥䜜䠈㝖䛟䛣䛸䛜ᅔ㞴䛺⫼ᬒ஦䛣䛸䜒䛒䜚䠈䛔䜝䛔䜝䛸㠃ಽ䛺ᡭ⥆䛝䛜ቑ䛘䠈ᐇ㝿䛾ᘓタ䛿ᙜึ㇟䛻䛺䜚ᚓ䜛䛜䠈䛣䜜䛻䛴䛔䛶䛿ᐇ㝿䛾ᐃ㔞䛸䝅䝭䝳䝺䞊䝅䝵ணᐃ䛛䜙༙ᖺ㏆䛟㐜䜜䛶䛔䜛䚹䛭䜜䛷䜒䠈䜘䛖䜔䛟䝕䝞䜲䝇〇㐀䞁䜢⏝䛔䛶 0.1 /kg/y ௨ୗ⛬ᗘ䛸ぢ✚䜒䜙䜜䛶䛚䜚䠈⌧≧䛷䛿䜢ᆅୗ⎔ቃ䛷⾜䛘䜛ẁ㝵䜎䛷᮶䛶䛚䜚䠈2019 ᖺ 2 ᭶䛻᭱ึ䛾୺せ䛺⫼ᬒ஦㇟䛷䛿䛺䛔[26]䚹

䝔䝇䝖〇㐀䛜⾜䜟䜜䠈᭱ึ䛻䛧䛶䛿䜎䛪䜎䛪䛾䜒䛾䛜ฟ᮶ୖ䛣䜜䜎䛷䛾◊✲䛛䜙䠈䛣䛖䛔䛳䛯⫼ᬒ஦㇟䜢┤᥋䝕䞊䝍ゎᯒ䛜䛳䛯䚹⌧ᅾ䠈ヲ⣽䛺ឤᗘ䜔෌⌧ᛶ➼䛾ᛶ⬟ホ౯䜢㐍䜑䛶䛔䛾୰䛷ศᯒ䛩䜛௨๓䛻䠈䛩䛷䛻〇㐀ẁ㝵䛷ᴃ෇ᙧ≧䝟䝷䝯䞊䜛䛸䛣䜝䛷䛒䜚䠈ᮏ᱁ⓗ䛺ᐇ㦂ᢞධ䜈䛾‽ഛ䜢㐍䜑䛶䛔䜛䚹⌧ᆅ䝍䛰䛡䛷䛿ⴠ䛸䛧䛝䜜䛺䛔஦㇟䛜Ꮡᅾ䛧䠈䛭䜜䛿䝕䝞䜲䝇ෆ㒊䛾άື䛿䠈LNGS 䝣䜵䝻䞊䝅䝑䝥䛾 PD ◊✲ဨ䛷䛒䜛ὸ⏣Ặ䛜䛾ΰධ≀䛷䛒䜛䛣䛸䛜䜟䛛䛳䛶䛝䛯䚹⌧ᅾ䛾〇㐀⎔ቃ䛿䜽䝸䞊䞁୰ᚰ䛸䛺䛳䛶㐍䜑䛶䛔䜛䚹䜎䛯䠈᭱㏆ SNOLAB 䛾 science com-䝹䞊䝮䛷⾜䛳䛶䛔䜛䜟䛡䛷䛿䛔䛯䜑䠈䛭䛖䛔䛳䛯ΰධ≀䛜Ꮡᅾmittee (SC)䛛䜙䜒㛵ᚰ䛜♧䛥䜜䛶䛚䜚䠈䛩䛷䛻 SC 䝇䝍䝑䝣䛜ど䛩䜛䛾䛿୙ᛮ㆟䛷䛿䛺䛔䛜䛣䛖䛔䛳䛯䜒䛾䛜཯㊴ཎᏊ᰾஦㇟䛸ᐹ䛻ゼ䜜䛶䛔䜛䚹SNOLAB 䛿ᑗ᮶䛾䝬䝹䝏䝃䜲䝖䛷䛾 ᐃ䜔䜘ྠᵝ䛾ᙧ≧䜢ᣢ䛳䛶䛧䜎䛳䛶䛔䜛䛾䛿ၥ㢟䛷䛒䜚䠈ᑐ⟇䛜ᚲせ䜚ప䝞䝑䜽䜾䝷䜴䞁䝗ᐇ㦂䛻䛚䛡䜛ೃ⿵ᆅ䛸䛺䜚ᚓ䜛䚹䜎䛰ヲ⣽䛷䛒䜛䚹䜎䛯䠈୪⾜䛧䛶䠈䛣䜜䜙䜢ゎᯒⓗ䛻㝖ཤ䛩䜛䛣䛸䜒ᚲせ䛿௒ᚋ䛾㐍ᒎලྜ䛻౫Ꮡ䛩䜛䛜䠈䛥䜎䛦䜎䛺ᐇ㦂䝃䜲䝖䛷䛾ྠ䛷䛒䜚䠈ୖグ䛷㏙䜉䛯䜘䛖䛺ගᏛศゎ⬟௨ୗ䛾᝟ሗ䜢ྲྀᚓ䛩䜛ᵝ䛾䛸䛔䛖䛾䛿䜎䛥䛻䛣䛣䛻䛴䛺䛜䜛䜟䛡䛷䛒䜛䚹䛷㔜せ䛷䛒䜚䠈LNGS 䛰䛡䛻䛣䛰䜟䜙䛪ᆅୗᐇ㦂䛾㐠Ⴀᶵ㛵䛸᭱㏆䠈䛣䜜䜙䛾ΰධ≀䜢㆑ู䛩䜛ᡭẁ䛸䛧䛶఩┦᝟ሗ䜢౑䛖䛣䛸䜢ᥦ᱌䛧䠈ゎᯒ䝣䝻䞊䛻⤌䜏㎸䜐䛣䛸䜒㐍䜑䛶䛔䜛䚹఩┦᝟ᐃ䛸䛔䛖䛾䛿䛒䜙䜖䜛⫼ᬒ஦㇟䜢⣔⤫ⓗ䛻⌮ゎ䛩䜛䛖䛘䛾䝁䝭䝳䝙䜿䞊䝅䝵䞁䛿௒ᚋ䜒⥅⥆䛧䛶⾜䛳䛶䛔䛝䛯䛔䛸⪃䛘䛶䛔䜛䚹ሗ䛿䠈ᮏ᮶ගᏛീ䛾୰䛻䛿཯ᫎ䛥䜜䛺䛔≀⌮㔞䛷䛒䜚䠈⌧ᅾ䛾ගᏛゎᯒᢏ⾡䛷䛿䛣䛾᝟ሗ䜢౑䛘䛶䛔䛺䛔䚹䛣䛾᝟ሗ䜢ྍど໬䛩䜛䛾䛜఩┦ᕪගᏛ⣔䛷䛒䜚䠈఩┦ගᏛീ䛻䜘䛳䛶㆑ู䛷䛝䛺䛛䛳䛯⫼ᬒ஦㇟䛻䛴䛔䛶䜒䜽䝸䜰䛻ᕪู໬䛷䛝䜛䛣䛸䛜䜟䛛䛳䛶䛝䛯䚹ୖグ䛾ၥ㢟䛸ゎᯒ䝣䝻䞊䛾ᵓ⠏䜢᭱ඃඛ䛻㐍䜑䠈ᬯ㯮≀㉁᥈⣴䛾ᮏ᱁ⓗ䛺䝔䝇䝖ᐇ㦂䛻㐍䜣䛷䛔䛟䚹ᅗ 16

6. ᬯ㯮≀㉁᥈⣴ᐇ㦂࡟ྥࡅ࡚ᬯ㯮≀㉁᥈⣴ᐇ㦂䛿䠈≉䛻䠈Ᏹᐂ⥺䜔⎔ቃ୰ᛶᏊ䛜⫼ᬒ஦䜾䝷䞁䝃䝑䝋◊✲ᡤ䛾ᆅୗᐇ㦂᪋タ䠄Hall.F䠅䛻ᘓタ䛥䜜䛯䝕䝞䜲䝇〇㐀䝣䜯䝅䝸䝔䜱䞊䠄ᕥ䠅䛚䜘䜃᭱ึ䛾䝕䝞䜲䝇〇㐀䝔䝇䝖䛾ᵝᏊ䠄ྑ䠅

㇟䛸䛧䛶ᐤ୚䛧䛶䛧䜎䛖䛯䜑䠈ᆅୗ⎔ቃ䛷⾜䛖ᚲせ䛜䛒䜛䚹ᡃ䚻䛿䠈䜲䝍䝸䜰䞉䜾䝷䞁䝃䝑䝋◊✲ᡤ䠄LNGS䠅䜢᭱ึ䛾ᐇ㦂䝃䜲䝖䛸䛧䛶‽ഛ䜢㐍䜑䛶䛔䜛䚹䛣䛣䛿䠈OPERA ᐇ㦂䛾ᐇ㦂䝃䜲䝖䛷䜒䛒䛳䛯䛯䜑䠈ཎᏊ᰾஝ᯈ䛾䝝䞁䝗䝸䞁䜾䛻ᑐ䛧䛶⤒㦂䛜䛒䜚䠄≉䛻䠈⌧ീᗫᾮ➼䛾䜲䞁䝣䝷⎔ቃ䠅䠈ຠ⋡ⓗ䛺ᐇ㦂⎔ቃ䛾❧䛱ୖ䛢䛜ྍ⬟䛷䛒䜛䚹䜎䛯䠈䛣䛣䛷䛾᪂䛧䛔ヨ䜏䛿䠈䛣䜜䜎䛷ྡྂᒇ኱Ꮫ䛷䛾䜏⾜䛳䛶䛔䛯䝕䝞䜲䝇〇㐀⿦⨨䜢ึ䜑䛶እ㒊ᶵ㛵䛻ᵓ⠏䛧䠈䝕䝞䜲䝇౪⤥䜢⾜䛖䛣䛸䛷䛒䜛䚹᪂䛯䛺〇㐀⿦⨨䛾❧䛱ୖ䛢䛿 2017 ᖺ 䛛䜙䝕䝄䜲䞁タィ䜒ྵ䜑⾜䜟䜜䠈ྡྂᒇ኱Ꮫ
ᢏ⾡⫋ဨ䛾ఀ⸨Ặ䛻ከ኱䛺༠ຊ䜢㡬䛝䛺䛜䜙㐍䜑䜙䜜䛯䚹䜎䛪䠈2018 ᖺ 2 ᭶䛻ྡྂᒇ኱Ꮫ䛻⿦⨨䛾䝟䞊䝒䜢⣡ရ䛧䠈䛭䛣䛛䜙⿦⨨䛾⤌䜏ୖ䛢䠈䛥䜙䛻㥑ືไᚚ䝋䝣䝖䜴䜵䜰䛾ᵓ⠏䜢᏶஢䛧ືసヨ㦂䜢⾜䛳䛯䚹ືసヨ㦂䛷኱䛝䛺ၥ㢟䛜䛺䛔䛣䛸䜢☜ㄆ䛧䠈
8 ᭶䛻෌ᗘゎయ䛧 LNGS 䜈㍺㏦䛧䛯䚹10 ᭶䛻↓஦⿦⨨䛜฿╔䛧䠈⌧ᆅ䛷⤌䜏ୖ䛢䞉ヨ㦂䜢⣙ 2 㐌㛫䛛䛡䛶⾜䛔䠈2019 ᖺ 1 ᭶䛛䜙ᐇ㝿䛾ヨ㦂㐠⏝䜢㛤ጞ䛧䛯䚹ᆅୗ䛾ᐇ㦂⎔ቃ䛸䛧 䛶 䠈Hall.F 䛸࿧䜀䜜䜛䝖䞁䝛䝹ෆ䛻䝥䝺䝝䝤䛜ᘓタ䛥䜜䠈ᅗ 16 䛾䜘䛖䛺⎔ቃ䛜ᵓ⠏䛥䜜䛯䚹௒ᚋ䠈䝥䝺䝝䝤ෆ䜢䜽䝸䞊䞁䝹䞊䝮䛸䛧䛶㐠⏝䛩䜛ணᐃ䛻䛺䛳䛶䛔䜛䚹ᐇ䛿䠈䛣䛣 1䠈2 ᖺ䛷 LNGS 䛾䝉

7. ┠ᣦࡍ≀⌮㻌 DAMA/LIBRAᐇ㦂[26]䛿䠈ᬯ㯮≀㉁䝣䝷䝑䜽䝇䛾Ꮨ⠇ኚື䜢
12.9䃢䛾ಙ㢗ᗘ䛷ほ䛧䛯䛸୺ᙇ䛧䛶䛔䜛䚹NEWSdmᐇ㦂䛷䛿᭱ึ䛾䝍䞊䝀䝑䝖䛸䛧䛶䠈ᶆ‽ⓗ䛺ᬯ㯮≀㉁䝰䝕䝹䜢௬ᐃ䛧䛯ሙྜ䛻ᮇᚅ䛥䜜䜛DAMA/LIBRA䛾᭷ຠ㡿ᇦ䠄ᬯ㯮≀㉁㉁㔞
⣙10GeV/c2䠈ᬯ㯮≀㉁-᰾Ꮚ᩿㠃✚10-40cm2䠅䛻䛚䛔䛶᪉ྥឤᗘ䜢ᣢ䛳䛯᥈⣴䜢⾜䛔䛯䛔䛸⪃䛘䛶䛔䜛䚹≉䛻䠈ᬯ㯮≀㉁䛾≉ᛶ䛻ᙉ䛟౫Ꮡ䛧䛺䛔ᩓ஘䝰䝕䝹䠄䛣䛣䛷䛿spin-independent䠅䛻䛴䛔䛶䠈཯㊴᰾䛻䛚䛡䜛ᙎᛶᩓ஘䝰䝕䝹䠈䛚䜘䜃Maxwellศᕸ䜢ᣢ䛴ᬯ㯮≀㉁㏿ᗘศᕸ䝰䝕䝹䛻䛚䛔䛶䛾ྍ⬟ᛶ䜢㆟ㄽ䛩䜛䚹䜎䛯䠈NIT䛾䜘䛖䛺ᶆⓗ᰾䛜ᩘ✀㢮ᣢ䛴䛣䛸䜢฼⏝䛧䛯ᶆⓗ᰾౫Ꮡᛶ䛻䛴䛔䛶䛾ゎᯒ◊✲䜢⾜䛔䛯䛔䛸⪃䛘䛶䛔䜛䚹䛭䛾䛯䜑䛻䛿䠈ᅗ16䛻䛚䛡䜛ឤᗘ᥎ᐃ䛻䛚䛔䛶䠈ᶆⓗ㔜㔞䛷⣙10kg䛾᳨ฟჾ䛷1ᖺ⛬ᗘ䛾ほ䛜ᚲせ䛷䛒䜛䚹NIT䝕䝞䜲䝇䛭䛾䜒䛾䛿㠀ᖖ䛻㧗䛔ឤᗘ䜢᭷䛧䛶䛔䜛䛯䜑䠄ᅗ16 㯮⥺Device potential䠅䠈䛣䛾䝇䜿䞊䝹䛿ㄞ䜏ฟ䛧⬟ຊ䛻䛛䛛䛳䛶䛔䜛䚹6❶䛷㏙䜉
䛯〇㐀⿦⨨䛻䛚䛔䛶䛿䠈⣙1kg䜢1㐌㛫௨ෆ䛷〇㐀ྍ⬟䛷䛒䜛䚹䜎䛯䠈⿦⨨䛾䝬䜲䝘䞊䛺ᨵⰋ䛸ຠ⋡໬䛻䜘䜚2㐌㛫䛷5kg⛬ᗘ䛾

ͷͲͻ
25

㻌 䝞䜲䝥䝻䝎䜽䝖䛸䛧䛶䠈ᆅୗ⎔ቃ䛻䛚䛡䜛୰ᛶᏊ䝣䝷䝑䜽䝇䛾⢭ᐦ䛺ᐃ䜒ྍ⬟䛷䛒䜛䚹䛩䛷䛻䠈㧗䜶䝛䝹䜼䞊䝙䝳䞊䝇[27]䛷

⤂௓䛥䜜䛶䛔䜛᪂Ꮫ⾡㡿ᇦ䛂Ᏹᐂ䛾Ṕྐ䜢䜂䜒ゎ䛟ᆅୗ⣲᰾◊✲ (2013-2018)䛃B02 ⌜䛛䜙ὴ⏕䛧䛯୰ᛶᏊᐃ䝁䞁䝋䞊䝅䜰

䝮䛾୍⎔䛷㐍䜑䛶䛔䜛䝥䝻䝆䜵䜽䝖䛷䜒䛒䜚䠈NIT 䛿㝧Ꮚ཯㊴䜢⏝䛔䜛䛣䛸䛷䝃䝤 MeV 䛾୰ᛶᏊ䜢⢭ᗘⰋ䛟ᐃ䛧䠈䛥䜙䛻᪉ྥ᝟ሗ䜒ྲྀᚓ䛩䜛䛣䛸䛜䛷䛝䜛䚹౛䛘䜀䠈NIT 䜢⏝䛔䜛䛣䛸䛷ᅗ 18䛻♧䛩䜘䛖䛻༢Ⰽ䛾୰ᛶᏊ※䛛䜙䛾୰ᛶᏊ䛾䜶䝛䝹䜼䞊෌ᵓᡂ䛻ᡂຌ䛧䛶䛔䜛䚹䛣䜜䛿䠈཯㊴㝧Ꮚ䜶䝛䝹䜼䞊䛸᪉ྥ䛾ྠ᫬ᐃ䛜ྍ⬟䛷䛒䜛䛣䛸䛛䜙ᡂ䛫䜛ᴗ䛷䛒䜛䚹䛥䜙䛻䠈䛣䛾䛸䛝䛾㣕⛬䛿ᩘ μm 䛸ᬯ㯮≀㉁᳨ฟ䛸ẚ䜉䛶᱁ẁ䛻᳨ฟ䛜䛧䜔䛩䛔䛯䜑䠈䛭䛾ศ䜺䞁䝬⥺䛸䛾ศู⬟ຊ䛜᱁ẁ䛻㧗䛔䠄ᩘ䛛᭶䛾⎔ቃ
ᅗ 17 10kg䞉y 䛾 exposure 䛻䛚䛔䛶ᮇᚅ䛥䜜䜛ᬯ㯮≀㉁㉁㔞䛻ᑐ䜺䞁䝬⥺䛾᭚㟢䛷䜒ၥ㢟䛻䛺䜙䛺䛔䝺䝧䝹䠅䚹NEWSdm ᐇ㦂䛷䛩䜛 spin 䛻౫Ꮡ䛧䛺䛔ᬯ㯮≀㉁-᰾Ꮚ᩿㠃✚䛾ឤᗘ᥎ᐃ䚹㟷䛿⌧┠ᣦ䛩 10kg ⣭䛾ᐇ㦂䛜ᐇ⌧䛷䛝䜜䜀䠈ᆅୗ⎔ቃ䛾୰ᛶᏊ䛾ᅾㄞ䜏ྲྀ䜚ຠ⋡䜢⪃៖䛧䛯ሙྜ䛷䛒䜚,㉥䛿 LSPR ➼䛾㉸ゎീἲ䜢䝣䝷䝑䜽䝇䛸᪉ྥศᕸᐃ䠈䛥䜙䛻䛿Ꮨ⠇ኚືᐃ䜒ྍ⬟䛷䛒䜚䠈

⏝䛔䛶䜶䝛䝹䜼䞊㜈್䜢ୗ䛢䛯ሙྜ䚹㯮䛿,䝕䝞䜲䝇䛻グ㘓䛥䜜䛯⫼ᬒ஦㇟䛾ほⅬ䛛䜙 DAMA/LIBRA ᐇ㦂䛷ほ䛥䜜䛯Ꮨ⠇ኚ

㣕㊧䜢䛩䜉䛶ㄞ䜏ฟ䛫䛯ሙྜ䛾ឤᗘ䚹㉥䛔᭷㝈䛾㡿ᇦ䛜,ື䛻㛵䛩䜛᪂䛯䛺ᣦ㔪䜒ᚓ䜙䜜䜛䛛䜒䛧䜜䛺䛔䚹䜎䛯䠈䝙䝳䞊䝖䝸

DAMA/LIBRA 䛷ほ䝜䛾䝁䝠䞊䝺䞁䝖ᩓ஘䛻䛴䛔䛶䜒ཎᏊ᰾䛾ᙎᛶᩓ஘䛻䛚䛡䜛᪉䛥䜜䛯ಙྕ䛜ᬯ㯮≀㉁䛰䛳䛯ሙྜ䛾᭷ຠ㡿ᇦ䛷䛒䜛䚹

᳨ฟჾసᡂ䛿ྍ⬟䛷䛒䜛䠄10kg䝇䜿䞊䝹䛾〇㐀䛻䛚䛔䛶䛿䠈䛥䜙䛻୍ᅇ䜚〇㐀䝇䜿䞊䝹䛾኱䛝䛺⿦⨨䜢ᑟධ䛩䜛ணᐃ䛷䛒䜛䠅䚹ၥ㢟䛸䛺䜛䛾䛿ගᏛゎᯒ䝅䝇䝔䝮䛻䛚䛡䜛ㄞ䜏ྲྀ䜚䝇䝢䞊䝗䛷䛒䜛䚹⌧≧䛾㏿ᗘ䛿䠈୍ྎ䛒䛯䜚10g䛾ㄞ䜏ྲྀ䜚䛻䜒༙ᖺ⛬ᗘ䛛䛛䛳䛶䛧䜎䛖䛯䜑䠈䛣䜜䛻䛴䛔䛶䛿䠈୍ྎ䛾⿦⨨䛾㏿ᗘྥୖ䛸ྎᩘ䜢ቑ䜔䛩䛣䛸䛷᭱⤊ⓗ䛺㏿ᗘ䠄10kg䝇䜿䞊䝹䜢୍ᖺ௨ෆ䛻ㄞ䜑䜛䝇䝢䞊䝗䠅䜢㐩ᡂ䛧䛯䛔䚹⿦⨨䛾㏿ᗘྥୖ䛻䛴䛔䛶䛾᪉㔪䛸䛧䛶䠈᧜ീ㏿ᗘ䛾ྥୖ䛸䛭䜜䛻௜㝶䛧䛯ග※䛾䝇䝖䝻䝪໬䠈㥑ື⣔䛾㧗㏿໬᭱⤊ⓗ䛻䛿పಸ⋡໬䛻䜘䜛୍ḟೃ⿵஦㇟㑅ู䠄ගᏛ㍤ᗘ᝟ሗ䛻䜘䜛ศゎ⬟䛻ᐤ䜙䛺䛔ೃ⿵஦㇟䛾୍ḟ㑅ู䜒䛧䛟䛿ᶵᲔᏛ⩦➼䜢⏝䛔䛯஦㇟ᙧ≧䛾䝁䞁䝪䝸䝳䞊䝅䝵䞁䠅䜢୪⾜䛧䛶㛤Ⓨ䜢㐍䜑䠈䛩䛷䛻᪥ᮏ䛸䜲䝍䝸䜰䛻Ꮡᅾ䛩䜛5ྎ䛾⿦⨨䜒䜰䝑䝥䜾䝺䞊䝗䛩䜛䚹ྥ᝟ሗ䜒ྠ᫬䛻ィ䛷䛝䜛䛯䜑䠈䜘䜚⢭ᐦ䛺ほ䛜ྍ⬟䛷䛒䜚䠈

౛䛘䜀䠈䛩䛷䛻ᐇ㦂䛜䛺䛥䜜䛶䛔䜛 Oak Ridge 䛾 SNS 䝋䞊䝇䛷䛾ほ [28]䛷ゝ䛘䜀䠈10 kg䞉y 䛾ᐇ㦂䛷 100event ⛬ᗘ䛾ಙྕ
䠄100nm ௨ୖ䠅䛜᳨ฟ䛷䛝䜛䛸䛔䛖ぢ✚䜒䜚䜒䛒䜛䚹䛥䜙䛻䠈㏆ᖺ
䛷䛿 NIT 䛾Ⓨග⌧㇟䛾Ꮡᅾ䜒᫂䜙䛛䛻䛺䛳䛶䛔䜛[29]䚹ⓑ▼䜙䛾◊✲䛻䜘䜚 AgBr(I)⤖ᬗ䛾䃐⥺Ⓨග䛻䛴䛔䛶䛿䠈ⓎගἼ㛗䛜
540 nm ⛬ᗘ䛾᫬ᐃᩘ䛜 1μs ⛬ᗘ䛾 fast ᡂศ䛸 560nm ⛬ᗘ䛾ᩘ 10μsec ௨ୖ䛾 slow ᡂศ䛜Ꮡᅾ䛩䜛䛣䛸䛜䜟䛛䜚䠈䛣䛾ᶵᵓ䛜 AgBr䠄I䠅⤖ᬗෆ䛻䝗䞊䝥䛥䜜䛯䝶䜴⣲䛻䛚䛡䜛➼㟁Ꮚ䝖䝷䝑䝥䛻᮰⦡䛥䜜䛯ṇᏍ䛸㟁Ꮚ䛻䜘䜛᮰⦡ບ㉳ᏊⓎග䠈䛚䜘䜃⾲㠃㟁Ꮚ䝖䝷䝑䝥䛻᮰⦡䛥䜜䛯㟁Ꮚ䛸䛾䝖䞁䝛䝹ຠᯝ䛻䜘䜛෌⤖ྜ䛻䜘䜛䜒䛾䛷䛒䜛䛣䛸䛜䜟䛛䛳䛶䛝䛯䚹䛣䛖䛔䛳䛯≉ᛶ䛿䠈㣕㊧᳨ฟ䛸ග᳨ฟ䛻䜘䜛䝝䜲䝤䝸䝑䝖䛺᝟ሗྲྀᚓ䛻䜘䜚ⓎගἼ㛗䜔᫬ᐃᩘ䛻䜘䛳䛶⢏Ꮚ㆑ู⬟䜢ᣢ䛳䛶䛔䜛ྍ⬟ᛶ䜢♧၀䛩䜛䚹䛣䛖䛔䛳䛯ᐃ䛜䛷䛝䜜䜀ᬯ㯮≀㉁᥈⣴ᐇ㦂䛻䛚䛔䛶䜒㠉᪂ⓗ䛺᳨ฟ

ჾ䛸䛺䜛䚹

8㸬ࡲ࡜ࡵ
㻌 ᮏ✏䛻䛚䛔䛶䠈䛣䜜䜎䛷䛾 NEWSdm ᐇ㦂䛾ᇶ┙䛸䛺䛳䛶䛔䜛㉸ᚤ⢏ᏊཎᏊ᰾஝ᯈ (Nano Imaging Tracker : NIT)䛸䛔䛖᪂䛧䛔᳨ฟჾ䛾㛤Ⓨ䛾⤒⦋䛸⌧≧䠈䛥䜙䛻 NEWSdm ᐇ㦂䛾⌧≧䛸䛭䛾ᢏ⾡ᛂ⏝䛻䛴䛔䛶⤂௓䛥䛫䛶䛔䛯䛰䛔䛯䚹ᮏ◊✲䛿䠈䇾䝘䝜䝖䝷䝑䜻䞁䜾”䜢䜻䞊䝽䞊䝗䛻䛥䜎䛦䜎䛺ศ㔝䜢㉸䛘䛯䝔䜽䝜䝻䝆䞊䜢ᑟධ䛧䠈ᬯ㯮≀㉁䛾ㅦ䛻㏕䜝䛖䛸䛧䛶䛔䜛䜒䛾䛷䛒䜚䠈ᢏ⾡䛭䛾䜒䛾䛜᪂䛧䛔䛜䜖䛘䛻ከ䛟䛾ㄢ㢟䜒ṧ䛥䜜䛶䛔䜛䚹䛭䛖䛔䛳䛯ㄢ㢟䛻䛴䛔䛶䠈⌧ᅾ䠈኱Ꮫ㝔⏕䜔ඹྠ◊✲⪅䛸ඹ䛻୍
ᅗ 18 560keV ┦ᙜ䛾༢Ⰽ୰ᛶᏊ䛻䜘䛳䛶཯㊴䛥䜜䛯㝧Ꮚ㣕㊧䛾䜶䝛䝹䜼䞊䠄㣕⛬䠅䛸ゅᗘ䛛䜙෌ᵓᡂ䛥䜜䛯୰ᛶᏊ䜶䝛䝹䜼䞊䝇䝨䜽䝖䝹䛴୍䛴ၥ㢟䜢ゎỴ䛧䠈╔ᐇ䛻๓䛻㐍䜣䛷䛔䜛◊✲䛷䜒䛒䜛䛯䜑䠈᫬㛫䛿䛛䛛䛳䛶䛧䜎䛳䛶䛔䜛䛜䠈䛭䜜䛺䜚䛻䝴䝙䞊䜽䛺䇾ఱ䛛䇿䜢௒ᚋ䜒䜰䜴䝖䝥䝑䝖䛷䛝䜛䛿䛪䛷䛒䜛䚹ㄞ⪅䛾᪉䛻䛿䠈᫝㠀䛣䛖

ͷͳͲ
26

䛔䛳䛯᪂䛯䛺ᐇ㦂ᢏ⾡䛜䛒䜛䛣䛸䜒▱䛳䛶䛔䛯䛰䛝䠈䛥䜎䛦䜎䛺[18] K. Kimura and T. Naka, Nucl. Inst. and Meth. A Vol.

㆟ㄽ䜔ᥦ᱌䜢㡬䛡䛯䜙ᖾ䛔䛷䛒䜛䚹

680, 12-17 (2012)9. ㅰ㎡[19] K.Katsuragawa, A.Umemoto, M.Yoshimoto, T. Naka
and T. Asada, “New readout system for submicron tracks㻌 ᮏ◊✲䛿䠈➹⪅䜈┤᥋ᣦᑟ䛔䛯䛰䛔䛯ኟ┠Ặ䛾ඛ㥑ⓗ䛺◊

with nuclear emulsion”, JINST Vol.12, T04002(2017)✲䛛䜙ጞ䜎䜚䠈ከ䛟䛾኱Ꮫ㝔⏕䠈ඹྠ◊✲⪅䠈䛥䜙䛻䛥䜎䛦䜎䛺[20] B. J. Messinger, K. U. von Raben, R. K. Chang and P. W.

ᢏ⾡ⓗᨭ᥼䜢䛔䛯䛰䛔䛯◊✲⪅䞉ᢏ⾡⪅䛾༠ຊ䛻䜘䛳䛶ᡂ䜚

Barber, Phys. Rev. B, Vol., 24, 649 (1981)❧䛳䛶䛔䜎䛩䚹୍ே䜂䛸䜚ྡ๓䜢ᣲ䛢䜛䛣䛸䛿⣬㠃䛾㛵ಀୖ㞴

[21]Web site of the Nobel Prize foundation:䛧䛔䛷䛩䛜䠈䛣䛣䛻ᨵ䜑䛶ឤㅰ䛔䛯䛧䜎䛩䚹䜎䛯䠈௒⌧ᅾ䜒ඹ䛻belprize.org/prizes/chemistry/2014/summary/◊✲䜢⾜䛳䛶䛔䜛◊✲⪅䞉኱Ꮫ㝔⏕䛾ᡂᯝ䛻䜘䛳䛶ᮏ✏䛾ᇳ[22] Atsuhiro Umemoto, Tatsuhiro Naka, Andrey Alexandrov and➹䛻⮳䛳䛯䛣䛸䜢ᚰ䛛䜙ឤㅰ䛔䛯䛧䜎䛩䚹䜎䛯䠈᪂Ꮫ⾡㡿ᇦ䛂Ᏹ

Masahiro Yoshimoto, PTEP 2019,013D02 (2019)ᐂ䛾Ṕྐ䜢䜂䜒䛸䛟ᆅୗ⣲᰾◊✲䛃B02 ⌜䜢㏻䛧䛶䠈ከ䛟䛾᪉䚻

[23] A. Aleksandrov et al., Nucl.Instrum.Meth. A Vol.824,䛸䛾஺ὶ䜒ᮏ◊✲䜢㐍䜑䜛䝗䝷䜲䝡䞁䜾䝣䜷䞊䝇䛾୍䛴䛻䛺䛳䛶

600-602 (2016)䛚䜚䠈௒ᚋ䛸䜒᫝㠀䛥䜎䛦䜎䛺ᙧ䛷㐃ᦠ䞉㆟ㄽ䜢㈷䜜䜀ᖾ䛔䛷䛩䚹㻌[24] M.Kimura et al., Nucl. Inst. Meth.A Vol. 845,373-377

㻌(2017)

ཧ⪃ᩥ⊩[23] G. Alimonti et al., (Borexino collaboration), Phys.

[1] J. H. Oort, Com. Obs. at Leiden, Vol. VI, No. 238, 249-

Lett. B vol.422, Iss. 1-4, 349-358 (1998)

287 (1932)[25] A. Alexandrov et al., Astropat. Phys. Vol. 80,16-21[2] Zwicky, F., Helvetica Physica Acta 6:110127 (1933)(2016)[3] Zwicky, F., Astrophysical Journal 86: 217-246 (1937)[26] R. Bernabei et al., Nucl. Phys. At. Energy Vol. 19, Iss.

https://www.no-[4] Vera C. Rubin et al., Astro.phys. J., 225:L107-111㻌

4, 307-325 (2018)(1978)[27] ⏣ ୰ 㞞 ኈ 㸪ᖇ 㔚 ⛸ ௓ 㸪㕥 ᮌ ඃ 㣕 㸪ྜྷ ᮏ 㞞 ᾈ 㸪㧗

[5] Dan P. Clemens, Astrophys. J. 295: 422-436 (1985)࢚ ࢿ ࣝ ࢠ ࣮ ࢽ ࣗ ࣮ ࢫ 㸪 Vol.35, No.4 (2017)[6] Toshihiro Omodaka, AAPPS Bulletin, Vol. 19, No. 3,[28] D. Akimov et al., Science Vol. 357,Issue 6356 (2017)19-25 (2009)[29] T.Shiraishi, H.Ichiki and T.Naka, Nucl. Inst.

[7] Marc Kamionvsky, High Energy Physics and Cosmology. 14: 394.: arXiv:hep-ph/9710467 (1997)[8] D.N.Spergel et al., Phys. Rev. D37,1353(1988)[9] Kiseki Nakamura et al., PTEP Vol.2015,Iss. 4,043F01(2015)[10] A. Aleksandrov et al., (NEWS collaboration),
arXiv:1604.04199 [astro-ph.IM] (2016)[11]బ⸨ಟ䠈ᑠᯇ㞞ᏹ䠈㧗䜶䝛䝹䜼䞊䝙䝳䞊䝇㻌 Vol.34,No.2(2015)[12] Taku Nakamura et al., Nucl. Instr.Meth A,Vol. 556
Iss. 1, 80-86 (2006)[13] M. Natsume et al., Nucl. Instr. Meth A,Vol. 557 Iss.
3, 439-443 (2007)[14] T. Naka,et al., Nucl. Inst. Meth. A Vol. 718, 519-521(2013)[15] Takashi Asada, Tatsuhiro Naka, Ken-ichi Kuwabara
and Masahiro Yoshimoto, PTEP Vol.2017, Iss.6, 063H01(2017)[16] K.Morishima, T.Nakano JINST Vol.5, P04011 (2010)[17] Masahiro Yoshimoto, Toshiyuki Nakano, Ryosuke
Komatani, Hiroaki Kawahara, PTEP Vol.2017, Iss.10,
103H01 (2017)

Meth. A (2019) Volume 927, 21 (2019)