188˙ ‫঺ڀݚ‬հ

CERN Summer Student Programme 2019 ࢀՃใࠂ‫౎ژ‬େֶɹཧֶ‫ڀݚ‬ՊԆᢛ ࢵੈenyo.shiyo.77z@st.kyoto-u.ac.jp
2019 ೥ (ྩ࿨‫ݩ‬೥) 9 ݄ 24 ೔͸͡Ίʹ

1Δ৔ॴΛ‫ͱ͖ͨ͜Ͱֶݟ‬͸, ࠓͰ΋Ұ൪ҹ৅ʹ࢒͍ͬͯΔɻ࣮‫ܞʹݧ‬ΘΔऀͱͯ͠શ͕ͯૉ੖Β͍͠‫ͬ͋Ͱݧܦ‬6 ݄ 24 ೔͔Β 8 ݄ 30 ೔·Ͱͷ 10 िؒ, CERN Summer Student Programme 2019 ʹࢀՃ͍͍ͤͯͨͩ͞

ͨɻ·ͨૉཻࢠ෺ཧֶ࣮‫ؔʹݧ‬ΘΔ࣮‫ݧ‬΍‫ݕ‬ग़‫͍ͭʹث‬ͨɻ͜ͷϨϙʔτͰ͸ͦͷ‫׆‬ಈʹ͍ͭͯใࠂ͢Δɻ‫ظ‬଴Ҏ্ͷՁ஋͕͋ͬͨɻͯͷϫʔΫγϣοϓ΋සൟʹ։࠵͞Ε͓ͯΓ, ͜ΕΒ΋͜ͷՆ, 300 ਓΛ௒͑Δੈքதͷֶੜ͕ CERN(Ԥभ‫ݪ‬ࢠ֩‫·ूʹ )ߏػڀݚ‬Γ, Πϯλʔϯγοϓͱ͍͏‫֤Ͱܗ‬࣮‫ݧ‬άϧʔϓͰ‫׆ڀݚ‬ಈΛߦͬͨ (ਤ 1)ɻࢲ͸ ATLAS

2.2Project࣮‫ݧ‬ͷ ITk(Inner Tracker) άϧʔϓͰϐΫηϧ‫ݕ‬ग़‫ث‬

2.2.1

֓ཁ

ͷςετΛͨ͠ɻ·ͨ, લ൒ͷ 5 िؒʹ͸ૉཻࢠɾ‫ࢠݪ‬ͳઐ߈ͷਓͨͪͱ෺ཧʹ͍ͭͯٞ࿦͢Δͱ͍͏‫و‬ॏͳ‫ܦ‬ATLAS ITk ͸࠷΋಺ଆʹҐஔ͢Δඈ੻‫ݕ‬ग़‫͋Ͱث‬Γ,LHC ͷ Phase-II(High Luminosity) ΞοϓάϨʔυͷ‫ݧ‬΋͢Δ͜ͱ͕Ͱ͖ͨɻࡍʹશ͕ͯγϦίϯ‫ݕ‬ग़‫ʹث‬มߋ͞ΕΔɻਤ 2 ʹΞοϓ֩෺ཧֶͷ࣮‫ݧ‬ɾཧ࿦ʹؔ͢Δߨ͕ٛߦΘΕͨଞ, ༷ʑάϨʔυ‫ޙ‬ͷ ITk ͷ໛ࣜਤΛࣔ͢ɻ಺ଆ͔Β 5 ૚໨·Ͱ͕ϐΫηϧ‫ݕ‬ग़‫ث‬, ͦͷ֎ଆ 4 ૚͕ετϦοϓ‫ݕ‬ग़‫ͱث‬
ͳΔ͕, ์ࣹઢଛইʹ‫͘ڧ‬, ͔ͭ෺࣭ྔΛ཈͑ͨ৽ͨͳ‫ݕ‬ग़‫ث‬Λ։ൃ͢Δ͜ͱ͕ෆՄܽͰ͋Δɻࢲ͕ࢀՃͨ͠ͷ͸, ͦͷϐΫηϧ‫ݕ‬ग़‫ث‬ͷ૚ͷ͏ͪ࠷֎૚ (5 ૚໨) ʹ࢖ΘΕΔ MALTA ͱ͍͏γϦίϯϐΫηϧ‫ݕ‬ग़‫ث‬ͷ։ൃΛߦ͍ͬͯΔάϧʔϓͰ͋Δɻࢲʹ༩͑ΒΕͨ՝୊͸,‫࡞ࢼࡏݱ‬ஈ֊ʹ͋Δ MALTA ͷςετ࣮‫͏࢖ʹݧ‬ιϑτ΢ΣΞͷվྑ, ͓Αͼৄࡉͳ threshold ͷࢼ‫ݧ‬Λ࣮ࢪ͢Δ͜ͱͰ͋ͬͨɻಛʹ, threshold ʹؔ͢Δแ‫ׅ‬తͳࢼਤ 1: Summer stuent 2019 ͷू߹ࣸਅ‫ݧ‬͸ࠓճ͕ॳΊͯͰ͋Γ, ͦΕʹΑͬͯ MALTA ͷੑೳධՁͱϊΠζܰ‫Ͳͳݮ‬, ࠓ‫ޙ‬ͷվྑʹ΋‫͕ܨ‬Δ‫ૅج‬σʔλΛఏ‫͢ڙ‬Δ͜ͱ͕Ͱ͖ͨɻ͜͜Ͱ͸࣮ࡍʹߦͬͨςετ݁Ռͷ͏ͪओཁͳ΋ͷʹߜͬͯ঺հ͍ͨ͠ɻ2‫׆‬ಈɾ‫಺ڀݚ‬༰

2.1

Visit & Workshop

ϓϩάϥϜͷؒ, CERN ͷ༷ʑͳࢪઃΛؒۙͰ‫͕ͳݟ‬Β, ࣮‫ࢀʹݧ‬Ճ͍ͯ͠Δ‫͔ऀڀݚ‬Β૷ஔͷઆ໌Λड͚Δͱ͍͏‫ػ‬ձʹ‫·ܙ‬Εͨɻ‫ ࡏݱ‬LHC ͕ด࠯‫͋ʹؒظ‬Δͨ
Ί, ஍্ʹ͋Δ ISOLDE ͳͲͷ࣮‫ࢪݧ‬ઃͷଞʹ, ஍Լʹ͋Δ ATLAS, ALICE, CMS Λ๚ΕΔ͜ͱ͕Ͱ͖ͨɻ͞Βʹ͸ DSF ͱ‫ݺ‬͹ΕΔ, γϦίϯ‫ݕ‬ग़‫ث‬Λ࣮ࡍʹ੡଄͢

2.2.2

MALTA Threshold scanMALTA(Monolithic pixel sensor from ALICE to ATLAS) ͸ CMOS ٕज़Λ࢖ͬͨ monolithic silicon pixeldetector Ͱ͋Γ, readout ճ࿏ͱγϦίϯϐΫηϧηϯαʔ͕Ұͭʹͳͬͨ‫ݕ‬ग़‫͋Ͱث‬Δɻ1 ͭͷ MALTA νοϓʹ͸ 36.4 μm ֯ͷϐΫηϧ͕ 512 × 512 ‫ݸ‬഑ஔ͞Εͯ

͍Δɻਤ 3 ʹϐΫηϧͷஅ໘໛ࣜਤΛࣔ͢ɻՙిཻࢠʹ

2
89

6500

# pixelthreshold [el]H2thres
550

5450
400

4350
3300
250

2200
1150100ਤ 2: Phase-II ΞοϓάϨʔυͰͷ ITk ͷ໛ࣜਤ [1]

0100

200

300

400

500
pix Col025

7# pixelnoise [el]H2noisecharged particle

620
5+ + + -15

4310

2
510

ਤ 3: MALTA ϐΫηϧͷஅ໘໛ࣜਤ [2][3]Αͬͯ༠‫͞ى‬Εͨిՙ͕, ਤ 3 ͷ n well collection elec-trode(n ‫ूʹ )ۃ‬ΊΒΕΔ͜ͱʹΑͬͯ‫ݕ‬ग़͞ΕΔɻ͜ͷ

0100

200

300

400500pix Col0ਤ 4: threshold εΩϟϯΛԣ 512 ྻ, ॎ 10 ྻʹରͯ͠ߦͬͨ݁Ռɻॎ࣠ͷ୯Ґ el ͸ిࢠϗʔϧରͷ਺Λද͢ɻ(্) ԣͷϐΫηϧ No. ʹର͢Δ threshold ͷ஋ͱ (Լ) ϊΠζͷ஋ɻి‫ۃ‬Λ 3 μm2 ͱখ͘͢͞Δ͜ͱʹΑΓ༰ྔੑϊΠζΛܰ‫͍ͯ͠ݮ‬ΔɻͦΕͧΕͷϐΫηϧ͕ shaper-ampliﬁer

MALTA ϓϩτλΠϓͰ͸ӈଆͷ front-end ͷΈ p ‫ܕ‬τͱ discriminator Λ‫ؚ‬ΉΞφϩά front-end Λ͓࣋ͬͯΓ, threshold Λ௒͑Δ৴߸͕‫ݕ‬ग़͞ΕΔͱσδλϧ৴ϥϯδελ͕௥Ճ͞Ε͓ͯΓ, ͜͜ΛྲྀΕΔϕʔεిྲྀIreset ͕ӈଆͷϊΠζΛ૿େ͍ͯ͠Δͱߟ͑ΒΕͨɻͦ߸ͱͯ͠ಡΈͩ͞ΕΔɻ͔͠͠, ͦͷઃఆΛ֤ϐΫηϧ͜Ͱ, Ireset ΛมԽͤͨ͞ͱ͖ʹνοϓӈଆͷϊΠζ஋ຖͰ͸ͳ͘νοϓશମͷ੍‫ͯ͠ͱޚ‬Ұ‫͍ͯͬߦͰׅ‬Δ͕ͨͲ͏มԽ͢Δ͔Λௐ΂ͨɻਤ 5 ʹϊΠζͷ Ireset ʹରΊ, ϐΫηϧؒͷ‫ۉ‬Ұੑ͕࣮༻Խ͢Δ্Ͱॏཁͳ໰୊ͱ͢ΔґଘੑΛࣔ͢ɻϊΠζ஋͸ Ireset ʹ໌Β͔ʹ૬ؔ͠ͳΔɻ͜Ε·Ͱ, ͜ͷ threshold ͷ‫ۉ‬Ұੑ΍ϐΫηϧຖ͓ͯΓ, ϊΠζͷࠨӈࠩ͸, p ‫ܕ‬τϥϯδελΛྲྀΕΔͷৼΔ෣͍Λ MALTA શମʹରͯ͠ਫ਼ࠪͨ͜͠ͱ͸΄ͱIreset ʹ‫ى‬Ҽͨ͠ճ࿏ಛੑͰ͋Δ͜ͱ͕໌Β͔ʹͳͬͨɻΜͲͳ͔͕ͬͨ, ࠓճͷςετʹΑͬͯৄࡉͳσʔλ͕ࠓճͷςετͰ͸, ֤ϐΫηϧʹ೾ߴΛม͑ͳ͕ΒΞφϩάςετύϧεΛೖΕ͍͖ͯ, threshold Λӽ͑σδλϧ৴߸ͱͯ͠ಡΈͩ͞ΕΔޮ཰ͷมԽΛௐ΂ͨɻ͜

Noise
Noise (el)ಘΒΕͨ͜ͱ͸, ࠓ‫ޙ‬ͷ։ൃʹ໾ཱͭॏཁͳ੒ՌͰ͋Δɻ

20

5thSec18

6thSec1614ΕΛΨ΢ε‫Ͱ਺ؔࠩޡ‬ϑΟοτͨ͠ࡍͷฏ‫ͱۉ‬ඪ४ภࠩΛͦΕͧΕ threshold, noise ͱͯ͠༻͍ͨɻਤ 4 ʹ, ͋Δνοϓʹରͯ͠ߦͬͨ threshold εΩϟϯͷ݁ՌΛࣔ

1210͢ɻࠓճςετΛߦͬͨ͢΂ͯͷνοϓ͕ࣅͨ݁ՌΛࣔ8͓ͯ͠Γ, threshold ͸֤ϐΫηϧຖͷ͹Β͖͕ͭগͳ

6͍͕, ϊΠζʹ͸νοϓͷࠨӈͰେ͖ͳ͕ࠩ͋Δ͜ͱ͕Θ͔ͬͨɻνοϓͷϊΠζͷࠨӈࠩ͸, ӈଆͱࠨଆͰͷ front-endͷճ࿏ߏ଄ͷҧ͍ʹΑΔͱ༧૝͞ΕΔɻ࣮ࡍ, ‫ࡏݱ‬ͷ

05

10

15

20

25

30

35

40IRESETਤ 5: Ireset ΛมԽͤͨ͞ͱ͖ͷϊΠζͷ஋ɻ5th, 6th ηΫλʔͱ͸νοϓશମΛ 8 ͭͷηΫλʔʹ෼͚ͨͱ͖ͷ 5 ͭ໨,6 ͭ໨ʹରԠ͢Δɻ

390

2.2.3

݁࿦ͱ·ͱΊ

10 िؒΛ௨ͯ͠ MALTA ʹؔ͢Δ༷ʑͳςετΛ࣮ࢪͨ͠ɻͦͷதͰ΋, threshold ʹؔ͢ΔॳΊͯͷਫ਼ີଌఆ͔Β, MALTA ͸ threshold ͷϐΫηϧຖͷҰ༷ੑʹؔͯ͠৴པͰ͖Δ‫ݕ‬ग़‫͋Ͱث‬Δ͜ͱ͕໌Β͔ʹͳͬͨɻ·ͨ, 1 ͭͷϐΫηϧΛεΩϟϯ͢Δ͕࣌ؒ 90 ඵͱඇৗʹ௕͘νοϓશମΛ؆୯ʹਫ਼ࠪͰ͖ͳ͍͜ͱ͕՝୊Ͱ͕͋ͬͨ, ࣮‫ݧ‬த΋ίʔυͷվળΛଓ͚Δ͜ͱͰߴ଎ԽΛߦ͍, εΩϟϯ࣌ؒΛ൒෼ʹ୹ॖ͢Δ͜ͱʹ੒ޭͨ͠ɻ͜ͷվྑ൛ͷίʔυ͕ࠓ‫ޙ‬ͷ‫ݕ‬ग़‫ث‬ςετʹ΋‫͞༻׆‬Ε͍ͯ͘ͱ‫ظ‬଴͞Ε, Ձ஋ͷ͋Δߩ‫͑ߟͱ͖ͨͰ͕ݙ‬ΔɻྲྀΛ͢Δ‫ػ‬ձʹ΋ଟ͘‫·ܙ‬Εͨɻ͔͠͠࠷΋ॏཁͳ͜ͱ͸, ༷ʑͳ΋ͷͷ‫ํݟ‬Λ஌Γࢲࣗ਎ͷࢹ໺Λ޿্͛ͨͰ,ࠓ‫Ͳޙ‬ͷΑ͏ʹ‫׆‬ಈ͍͔ͯ͘͠ͱ͍͏͜ͱͩͱࢥ͏ɻ͜ͷϓϩάϥϜͰͷ‫͕͜ݧܦ‬Ε͔Βͷ‫ڀݚ‬Λ๛͔ʹͨ͠ͱ‫͑ݴ‬ΔΑ͏ʹ, ָ͠Έͳ͕Β‫ؤ‬ுΓ͍ͨɻ
·ͨ, CERN ΍ CERN Ͱͷ࣮‫ݧ‬͸Ұൠͷਓʹ΋޿͘ೝ஌͞Ε͍ͯΔ͜ͱΛ࣮‫ͨ͠ײ‬ɻࠓ‫ޙ‬͸೔ຊࠃ಺ͰͷΞ΢τϦʔν‫׆‬ಈʹ΋ੵ‫ۃ‬తʹऔΓ૊Έ, Պֶͷ໘ന͞Λ‫ڞ‬༗͍͖͍ͯͨ͠ͱߟ͍͑ͯΔɻ

CERN Ͱ͸, ੲ summer student ͩͬͨਓ͕, ‫ݚʹޙ‬‫ ͼ࠶ͯ͠ͱऀڀ‬CERN ʹ໭͖ͬͯͨͱ͍͏࿩Λ਺ଟ͘ฉ͍ͨɻࢲͷ supervisor ΋ 10 ೥લͷ summer studentͩͬͨͦ͏ͩɻͦͷΑ͏ͳϓϩάϥϜʹ೔ຊਓͱͯ͠ࢀ

2.3

Student poster session ͳͲϓϩάϥϜதʹ։࠵͞Εͨϙελʔηογϣϯʹੵ‫ۃ‬ՃͰ͖ͨ͜ͱΛ‫ތ‬Β͘͠ࢥ͍ͬͯΔɻ·ͨ, ࠓ‫ͱޙ‬΋ͥͻ‫ܧ‬ଓ͍͖͍ͯͨͩͨ͠ͱࢥ͏ɻతʹࢀՃͨ͜͠ͱ΋, ࣗ෼ͷ‫͍ͯͭʹڀݚ‬ཧղΛਂΊΔͱͱ΋ʹ, ଞͷ summer student ͱҙ‫͖Ͱ׵ަݟ‬Δͱͯ΋ྑ͍‫ػ‬ձͰ͋ͬͨɻ·ͨ͜ͷ৔Ͱൃදͨ͜͠ͱͰ, ‫ݚ‬‫಺ڀ‬༰ʹ͍ͭͯ༑ਓͱ࿩͢͜ͱ͕૿͑, ࣗ෼ͷ‫͚ͩڀݚ‬Ͱͳ࣮͘‫ݧ‬άϧʔϓʹ͍ͭͯप஌Ͱ͖Δ͜ͱΛ͏Ε͘͠ࢥͬͨɻ͞ΒʹຖिͷάϧʔϓϛʔςΟϯάͰ͸ਐ௙ΛϓϨθϯ͢Δ‫ػ‬ձ͕ଟ͋͘Γ, ࣮‫ํݧ‬๏ͷఏҊ΍‫ʹڀݚ‬͍ͭͯ‫ʹൃ׆‬ٞ࿦͠, ༗༻ͳϑΟʔυόοΫΛಘΒΕͨ͜ͱ͕ඇৗʹॿ͚ʹͳͬͨɻ5ँࣙՖ֞࿨ଇ‫ڭ‬त, ໺ଜ‫·͞ࢠګ‬Λ͸͡Ίͱ͢Δ KEK ͷ

օ͞·ͷ͓͔͛Ͱ, ͜ͷϓϩάϥϜʹࢀՃ͢Δ͜ͱ͕Ͱ͖·ͨ͠ɻ·ͣ࠷ॳʹ, ૉ੖Β͍͠‫ݧܦ‬Λ͢Δ‫ػ‬ձΛ༩͑ͯͩͬͨ͘͜͞ͱ, ·ͨࡉ͔ͳͱ͜Ζ·ͰαϙʔτΛ͍͍ͯͨͩͨ͜͠ͱʹ͓ྱਃ্͍͛ͨ͠ͱࢥ͍·͢ɻ·ͨ,ࡕେɾ઒ാ‫و‬༟‫ڭ‬त, ‫ژ‬େɾ٢ా‫ڭॿࢢݡ‬, ͦͯ͠‫ژ‬େɾ‫ݪ‬ࢠ֩ɾϋυϩϯ‫ࣨڀݚ‬ͷΈͳ͞·ʹ͸, Ԡืॻྨͷ४උ͔Β౉ߤʹؔ͢Δ৘ใ·Ͱେม͓ੈ࿩ʹͳΓ·ͨ͠ɻ‫ݱ‬஍3ੜ‫׆‬ࢲ͸ϑϥϯεଆͷ St. Genis ʹ͋Δϗεςϧʹ଺ࡏ͠,ฏ೔͸ຖ೔‫ʹڀݚͰࣨڀݚ‬औΓ૊Ήଞ, lecture, visit ͳͲʹ΋ࢀՃ͍ͯͨ͠ɻ‫ٳ‬೔͸༑ਓͱ֎ʹग़͔͚Δ͜ͱ΋͋ͬͨɻͦΕͧΕͷࠃͷจԽ΍‫ڭ‬ҭʹ͍ͭͯ‫ʹ͍ޓ‬࿩ͨ͠Γ, কདྷͷ͜ͱ΍ੈؒҰൠʹऔΓ্͛ΒΕΔ༷ʑͳ໰୊ʹؔͯ͠ҙ‫ͨ͠׵ަݟ‬ΓͱେมܹࢗతͰ͋ͬͨɻࣗ෼ͷߟ͑Λ࣋ͭ͜ͱ, ͦΕΛ֎ʹ͔ͬ͠Γͱൃ৴͢Δ͜ͱ,Ͱ͸, Ұॹʹ‫ڀݚ‬Λߦͬͨ̏ਓͷ supervisor(Dr. Carlos
Solans Sanchez, Dr. Valerio Dao, Dr. Enrico JuniorSchioppa) ΍ ATLAS Pixel Group ͷօ͞·, summer
student team ͷօ͞·, ·ͨ CERN Ͱಇ͍͍ͯΔଟ͘ͷ‫ऀڀݚ‬ͷํʑʹ༷ʑͳ໘Ͱॿ‫ݴ‬, ྭ·͠Λ͍ͯͨͩ͠
͖·ͨ͠ɻ·ͨ, ͱ΋ʹࢀՃͨ͠ summer student શһʹ‫ँײ‬Λड़΂͍ͨͱࢥ͍·͢ɻؔΘͬͯͩͬͨ͘͢͞΂ͯͷօ͞·, ຊ౰ʹ͋Γ͕ͱ͏͍͟͝·ͨ͠ɻ·ͨଞऀͷҙ‫͔ݟ‬Β৽ͨͳߟ͑ΛಘΔ͜ͱ, ͜ΕΒ͕೔ৗͷձ࿩ϨϕϧͰ͑͞పఈͯ͠ߦΘΕ͍ͯΔ͜ͱΛ࣮‫ײ‬ͨ͠ɻͦΕͱಉ࣌ʹ, ࠓͷࣗ෼ʹ଍Γͳ͍΋ͷ͕ଟ͋͘Δͱ͍͏ͷ΋਎ʹછΈͯ‫ͨ͡ײ‬ɻ͢΂ָ͕͍ͯ͠‫Ͱݧܦ‬͕͋ͬͨ, ੵ‫ۃ‬ੑ, ओମੑ, ࣗ෼ͷཱͪҐஔʹର͢ΔཧղͳͲ, ࠃࡍతͳ‫ڝ‬૪ྗΛ࣋ͭͨΊʹඞཁͳྗΛࠓ‫ޙ‬͸ཆ͍͖͍ͬͯͨɻࢀߟจ‫ݙ‬[1] ATLAS Collaboration, Techinical Design Reportfor the ATLAS Inner Tracker Strip Detector,Tech. Rep., CERN-LHCC-2017-005, ATLASTDR-025, CERN, Geneva, 2017.
[2] I. Berdalovic, et al., 2018, JINST, 13, C01023.

4ࠓ‫ޙ‬ͷ๊ෛͱ summer student

programme ʹ๬Ή͜ͱੈք࠷ઌ୺ͷ‫Ͱॴڀݚ‬ͷ 10 िؒΛ௨ͯ͠, ૉཻࢠɾ‫ݪ‬ࢠ֩ͷཧ࿦΍࣮‫ݧ‬ΛֶͿͱಉ࣌ʹ, จԽɾ‫Ͳͳޠݴ‬ͷަ

[3] R. Cardella et al., 2019, JINST, 14, C06019.