Performance of scintillating tiles with direct silicon-photomultiplier (SiPM) readout for application to large area detectors

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Ins umen a ion
PAPER • OPEN ACCESS
Pe o mance o scin illa ing iles wi h di ec silicon-
pho omul iplie (SiPM) eadou o applica ion o
la ge a ea de ec o s
To ci e his a icle: A. Balla
e al
2022
JINST
17 P01038
View he a icle online o upda es and enhancemen s.
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This con en was downloaded om IP add ess 194.12.139.93 on 24/11/2025 a 13:28
2022 JINST 17 P01038
Published by IOP Publishing o Sissa Medialab
Recei ed:Oc obe 8, 2021
Accep ed:Janua y 17, 2022
Published:Janua y 27, 2022
Pe o mance o scin illa ing iles wi h di ec
silicon-pho omul iplie (SiPM) eadou o applica ion o
la ge a ea de ec o s
A. Balla,𝑎B. Buonomo,𝑎V. Ca a o,𝑏A. Calca e a,𝑎F. Ca delli,𝑎A. Ceccucci,𝑐
P. Ciamb one,𝑎V. Cice o,𝑏,𝑑 D. Di Gio enale,𝑎C. Di Giulio,𝑎G. Felici,𝑎L.G. Fogge a,𝑎
V. Gio dano,𝑏G. Lan anchi,𝑎I. Lax,𝑏A. Mon ana i,𝑏G. Papalino,𝑎A. Paoloni,𝑎,∗
T. Ro elli,𝑏,𝑑 A. Sapu i,𝑎G. To omeo𝑏and N. Tosi𝑏
𝑎INFN — Labo a o i Nazionali di F asca i,
ia E. Fe mi 40, 00044 F asca i (Rome), I aly
𝑏INFN — Sezione di Bologna,
Viale Be i Picha , 6/2, 40127 Bologna, I aly
𝑐CERN,
1211 Gene a 23, Swi ze land
𝑑Dipa imen o di Fisica e As onomia, Uni e si à di Bologna,
Viale Be i Picha , 6/2, 40127 Bologna, I aly
E-mail: [email p o ec ed]
Abs ac : The ligh yield, he ime esolu ion and he e iciency o di e en ypes o scin illa ing
iles wi h di ec Silicon Pho omul iplie eadou and ins umen ed wi h a cus omised on -end
elec onics ha e been measu ed a he Beam Tes Facili y o Labo a o i Nazionali di F asca i and
se e al es s ands. The esul s ob ained on minimum ionising pa icles wi h di e en de ec o
con igu a ions a e p esen ed. A ime esolu ion o he o de o 300 ps, a ligh yield o mo e han 230
pho o-elec ons, and an e iciency be e han 99.8% a e ob ained wi h
∼
225 cm
2
la ge a ea iles.
This echnology is sui able o a wide ange o applica ions in high-ene gy physics, in pa icula o
la ge a ea muon and iming de ec o s.
Keywo ds: Pho on de ec o s o UV, isible and IR pho ons (solid-s a e) (PIN diodes, APDs,
Si-PMTs, G-APDs, CCDs, EBCCDs, EMCCDs, CMOS image s, e c); Scin illa o s, scin illa ion and
ligh emission p ocesses (solid, gas and liquid scin illa o s)
A Xi eP in :2109.08454
∗Co esponding au ho .
c
2022 CERN. Published by IOP Publishing L d on behal o Sissa
Medialab. O iginal con en om his wo k may be used unde he e ms
o he C ea i e Commons A ibu ion 4.0 licence. Any u he dis ibu ion o his wo k
mus main ain a ibu ion o he au ho (s) and he i le o he wo k, jou nal ci a ion
and DOI.
h ps://doi.o g/10.1088/1748-0221/17/01/P01038
2022 JINST 17 P01038
Con en s
1 In oduc ion 1
2 The p o o ypes 2
3 F on -End Elec onics 2
4 De e mina ion o he in insic ime ji e o SiPMs and elec onics 5
5 Calib a ion o he ligh yield 6
6 Tes beam measu emen s 7
6.1 Tes beam se up 7
6.2 Tes beam esul s 8
7 Cosmic ays measu emen s 12
8 Simula ion 19
9 Conclusions 20
1 In oduc ion
O ganic scin illa o s o e a as esponse and high ligh yield o mode a e cos , making hem a
good choice o he applica ion in la ge a ea de ec o s o pa icle physics. Silicon Pho o-Mul iplie s
(SiPMs)
1
) [
1
] p o ide ad an ageous p ope ies such as good iming, compac ness, and high Pho on
De ec ion E iciency (PDE). Scin illa ing iles wi h di ec SiPM eadou , pionee ed o applica ion
in had on calo ime e s o elec on-posi on collide s [
2
,
3
], allow compac de ec o s wi h high
g anula i y and good ime esolu ion o be buil .
In addi ion o a e y good iming pe o mance, he choice o iles gua an ees he de e mina ion
o he
𝑥, 𝑦
coo dina es wi h a single ac i e laye and a good ole ance agains hi a e a ia ions.
S udies pe o med on simila scin illa o -based de ec o s [
4
] show ha his echnology is sui able
o de ec o s exposed o an in eg a ed dose o abou 100 kRad/yea . Mo eo e he cons uc ion and
assembly p ocedu e is modula and he e o e can be easily sha ed among di e en p oduc ion si es,
which is pa amoun o he cons uc ion o la ge a ea de ec o s.
This a icle desc ibes he pe o mance ob ained on 225 cm
2
a ea scin illa ing iles wi h di ec
SiPM eadou de eloped o possible use in la ge a ea muon sys ems, as o example, he muon
sys em o he p oposed SHADOWS expe imen [
5
]. Howe e , he modula s uc u e and he e y
compe i i e cos ende his sys em sui able o mul iple applica ions in high ene gy physics and
beyond, in pa icula o la ge a ea de ec o s.
1Also known as Mul i-Pixel Pho on Coun e s (MPPCs).
–1–
2022 JINST 17 P01038
2 The p o o ypes
Fou ile p o o ypes ha e been buil and cha ac e ised a se e al es s ands in F asca i and Bologna
INFN labo a o ies and hei pe o mance assessed du ing a es beam a he Beam Tes Facili y
(BTF) o Labo a o i Nazionali di F asca i in Janua y 2021.
Two (ou o ou ) iles a e made o EJ200 cas o ganic scin illa o om Eljen company
2
and he
o he wo by o ganic scin illa o om UNIPLAST (Vladimi , Russia). The iles dimensions a e o
(
150
×
150
×
10
)
mm
3
o bo h UNIPLAST and o Eljen company. Each ile is ead ou by ou
SiPMs placed a he ile co ne s, ei he eng a ed in o slo s dug in he scin illa o o glued a he
cu co ne s. An example o p o o ype wi h he ou SiPMs connec ed o lex cables and glued in
slo s eng a ed a he ile co ne s is shown in igu e 1. Th ee ou o ou iles a e pain ed wi h h ee
laye s o e lec i e pain ing Eljen EJ-510,
3
while he ou h one is co e ed by a chemical e lec o
ob ained by e ching he scin illa o su ace in a chemical agen , ha esul s in he o ma ion o a
whi e mic opo e deposi o e polys y ene [
6
]. All iles a e w apped wi h Te lon ape o ensu e ligh
igh ness. The main cha ac e is ics o he ou iles unde es a e summa ised in able 1.
Table 1
. Main cha ac e is ics o he ou iles unde es and a e age b eakdown ol age o he ou SiPMs in
each ile.
Scin illa o Dimensions SiPM placemen coa ing 𝑉b eak (V)
Tile 1 EJ200 (150 ×150 ×10)mm3slo s pain ing + Te lon 38.34 ±0.06
Tile 2 EJ200 (150 ×150 ×10)mm3co ne s pain ing + Te lon 38.43 ±0.09
Tile 3 UNIPLAST (150 ×150 ×10)mm3slo s e ching + Te lon 38.55 ±0.05
Tile 4 UNIPLAST (150 ×150 ×10)mm3slo s pain ing + Te lon 38.31 ±0.08
The iles a e ead ou by ou SiPMs, Hamama su S14160-6050HS, wi h 6
×
6mm
2
ac i e a ea.
The o he cha ac e is ics o he SiPMs, as deduced om he da ashee ,
4
a e epo ed on able 2. The
V-I cu e o e e y SiPM has been measu ed and he b eakdown ol age (
𝑉b eak
) de e mined. SiPMs
wi h simila
𝑉b eak
ha e been g ouped on each ile, o which he a e age
𝑉b eak
is also p o ided on
able 1, oge he wi h he ms o he ou alues. The SiPMs a e moun ed on sho Kap on lex cables
ha ensu e he connec ion wi h he mo he boa d (see sec ion 3). The lex cable end hos ing he
SiPM is glued o he ile ia op ical glue Eljen EJ-500.5The o he end is connec ed o mezzanines
placed on he mo he boa d a ached o he ile su ace, whe e he F on -End Elec onics (FEE) is
loca ed. All he de ails o he FEE a e gi en in sec ion 3.
3 F on -End Elec onics
The FEE o he ile p o o ypes has been designed ollowing a mo he -boa d/daugh e -boa ds
app oach wi h o - he-shel componen s. In his way di e en ampli ie opologies can be es ed
wi hou a ec ing he SiPM-boa d connec ions. The pic u e o a ully ins umen ed scin illa o ile is
shown in igu e 2.
2h ps://eljen echnology.com.
3h ps://eljen echnology.com/p oduc s/accesso ies/ej-510-ej-520.
4h ps://www.hamama su.com/eu/en/p oduc / ype/S14160-6050HS/index.h ml.
5h ps://eljen echnology.com/p oduc s/accesso ies/ej-500.
–2–
2022 JINST 17 P01038
Figu e 1
. Tile p o o ype wi h whi e e lec ing pain ing. The ou SiPMs a e a ached o lex cables glued in
g oo es inside he scin illa o a he ile co ne s.
Table 2
. Main cha ac e is ics o Hamama su S14160-6050HS SiPMs. The PDE, gain, da k cu en and
c oss alk alues a e gi en o he sugges ed ope a ion ol age o 𝑉b eak +2.7V.
Numbe o channels 1
Pixel pi ch 50 μm
Numbe o pixels 14331
𝑉b eak ∼38 V
PDE 50%
Gain o(106)
Typical da k cu en alue 2.5 μA
C oss alk p obabili y 7%
As well known he ime esolu ion depends on bo h signal slew a e and noise, he e o e pho on
collec ion mus be maximised by means o la ge a ea SiPMs and high bandwid h eadou elec onics.
Un o una ely la ge a ea SiPMs ha e a la ge pa asi ic capaci ance ha inc eases he ampli ie inpu
noise, educing he o e all signal- o-noise S/N a io. A educ ion o he pa asi ic capaci ance could
be achie ed by connec ing SiPMs in se ies, bu his con igu a ion equi es highe supply ol ages
and educes he signal ampli ude and he e o e i is no he bes choice o a opology whe e SiPMs
a e sp ead o e a la ge a ea.
Fo ou eadou opology, SiPMs ins umen ed wi h indi idual p eampli ie s ollowed by a com-
mon summing poin is a p e e able solu ion as i allows local signal ampli ica ion and he possibili y
o adjus ing he shaping ime bo h a he p eampli ie inpu and a he common summing poin .
The eadou ci cui block diag am is shown in igu e 2: each SiPM ou pu is ampli ied and
combined wi h signals om he o he ampli ie s by means o a summing ampli ie . The summing
ampli ie ou pu is, inally, ou ed o a digi ize . The mo he boa d connec ions ha e been designed
o equalise he p opaga ion delay o he signals om he ou (local) SiPM ampli ie s.
–3–

2022 JINST 17 P01038
AMPLIFIER1
SiPM1
AMPLIFIER2
SiPM2
AMPLIFIER3
SiPM3
AMPLIFIER4
SiPM4
SUMMING
AMPLIFIER
Figu e 2. Pic u e o a ully ins umen ed ile (le ) and i s eadou ci cui block diag am ( igh ).
The mo he -boa d PCB includes connec o s o bo h p eampli ie s and summing ampli ie , SiPM
bias ci cui s and low- ol age egula o s. Fou laye s PCBs ha e been used o p ope impedance signal
ou ing aces and low-impedance supply ol age dis ibu ion. MCX connec o s ha e been chosen
o analog signal ansmission while MOLEX nano- i connec o s ha e been used o low- ol age
and SiPM bias dis ibu ion.
The SiPMs a e connec ed o he p eampli ie ia low impedance sho kap on lex cables
allowing easy eplacemen o he ull eadou ci cui in case o ailu es.
Because o he SiPMs la ge pa asi ic capaci ance (o he o de o 2 nF), on -end p eampli ie s
wi h low inpu impedance mus be used.
Two basic con igu a ions ha e been selec ed o he on -end design: he cu en eedback and
he cu en con eyo . Fo each con igu a ion wo di e en eadou ci cui s ha e been in es iga ed;
he basic schema ics a e shown in igu e 3.
The i s wo ci cui s (Type 1 and Type 2) a e based on he cu en con eyo con igu a ion
6
and
implemen ed by means o a NPN BFR92A RF ansis o while Type 3 and Type 4 a e based on
he ansimpedance con igu a ion.
7
Table 3shows he main ea u es o he wo con igu a ions. All
ci cui s a e AC coupled hen allowing baseline luc ua ion supp ession using low capaci o s alues;
Type 1 ci cui includes a local bu e o pole-ze o compensa ion a he summing poin while Type 4
con igu a ion helps in supp essing pickup noise (wi hin he ampli ie bandwid h). All con igu a ions
ha e been es ed in a cosmic ay s and; a de ailed desc ip ion o he es ou come can be ound
in sec ion 7, while examples o he wa e o ms collec ed on he same ile wi h he ou di e en
elec onics is shown in igu e 4.
As he ou con igu a ions do no show signi ican di e ences in he ime esolu ion measu emen ,
he cu en con eyo one has been selec ed o ca y ou he Tes Beam, because i s esis i e inpu
impedance is s able o e all he inpu ansis o bandwid h.
Finally, o a oid spoiling he signal ime in o ma ion, low impedance connec ions o he
summing poin oge he wi h a high speed ampli ie mus be used; in ou design signals ha e been
6Cu en Con eyo : 𝑅𝑐=collec o esis o , 𝐶pa =collec o pa asi ic capaci ance
7T ansimpedance: 𝑅𝑓= eedback esis o , 𝐶pa =inpu pa asi ic capaci ance
–4–
2022 JINST 17 P01038
SiPM SiPM
SiPM
SiPM
SUM
SUM
SUM SUM
Vbias
VDD
VEE
VBIAS
TYPE 1
Vbias
VDD
VEE
VBIAS
TYPE 2
VBIAS
TYPE 3
VBIAS
TYPE 4
--- C: Use s elici D opbox NOTE SHADOW A icolo LT_SCHEMATICS p e_ ype1.asc ---
Figu e 3
. Di e en es ed FEE ypes. Type 1: bu e ed common base, Type 2: common base, Type 3: ansim-
pedence, Type 4: di e en ial eadou based on ansimpedence con igu a ion.
Table 3. P eampli ie con igu a ions cha ac e is ics (a ixed gain has been assumed).
Cu en Con eyo s T ansimpedance
𝑍in small (cu en sensi i e) 𝑍in ≃0( i ual g ound)
𝑍ou la ge (cu en ou pu ) 𝑍ou low ( ol age ou pu )
T ans e unc ion ≃𝑅𝑐T ans e unc ion ≃𝑅𝑓
𝑍in =1/𝑔𝑚𝑍in =𝑍𝑓/(𝐺+1)
Bandwid h=1/2𝜋𝑅𝑐𝐶pa Bandwid h=1/2𝜋𝑅 𝑓𝐶pa
ou ed by means o 50 ohm mic os ips while he summing poin has been implemen ed using he
AD8009, a e y as ope a ional ampli ie om Analog De ices.8
4 De e mina ion o he in insic ime ji e o SiPMs and elec onics
In o de o op imise he o e all design o he iles and co esponding on -end elec onics, i
is impo an o disen angle he indi idual con ibu ions o he combined ime esolu ion. The
con ibu ion o he SiPM i sel combined wi h he eadou elec onics has been measu ed wi hou he
8
he AD8009 is a high-speed cu en - eedback ampli ie (1 GHz bandwid h) om Analog De ices capable o exploi a
5500 V/μs slew a e esul ing in a sub-ns ise- ime i used in low-gain con igu a ions.
–5–
2022 JINST 17 P01038
Time (ns)
0 20 40 60 80 100 120 140 160 180 200
Ampli ude (mV)
100
200
300
400
500
Type 1 FEE
Time (ns)
0 20 40 60 80 100 120 140 160 180 200
Ampli ude (mV)
50
100
150
200
250
300
350
Type 2 FEE
Time (ns)
0 20 40 60 80 100 120 140 160 180 200
Ampli ude (mV)
0
50
100
150
200
250
300
350
Type 3 FEE
Time (ns)
0 20 40 60 80 100 120 140 160 180 200
Ampli ude (mV)
50
100
150
200
250
300
350
400
Type 4 FEE
Figu e 4. Examples o wa e o m acqui ed on ile 4 a 41.5 V bias ol age wi h he ou di e en FEE.
scin illa o . A pulse o ligh , p o ided by a
PiL040x
405 nm lase , was guided on o a single SiPM
connec ed o Type 2 FEE, as in he es beam. The pulse ampli ude was uned o ob ain signals o
ampli ude compa able o ha obse ed wi h MIPs.
The analog ou pu o he ampli ie was acqui ed oge he wi h he sync signal om he lase
on a LeC oy WR8000 oscilloscope, ope a ed a 20 GSamples/s. The oscilloscope was con igu ed o
measu e he ime di e ence be ween he wo signals, de ined as a cons an ac ion o he SiPM ou pu .
Two ac ions o he maximum ampli ude ha e been conside ed, 20% and 30%. The s anda d de ia-
ions o he di e ence, o e 1000 lase pulses, a e shown in igu e 5as a unc ion o SiPM bias ol age.
Since no ob ious dependency was obse ed, a simple a e age o e all he bias alues was aken,
yielding a ji e o 74(80) ps a 30(20)% cons an ac ion h eshold. Sub ac ing he ull con ibu ion
o he lase sys em (nominally 45 ps), a lowe limi o ji e o 66 ps a 20% h eshold was ound.
5 Calib a ion o he ligh yield
In o de o exp ess he iles ligh yield in numbe o pho o-elec ons, he gain o he SiPM and
eadou elec onics has been calib a ed by acqui ing i s signal cha ge spec um p oduced wi h a
low-in ensi y pulsed led ligh . The ha dwa e se up used o his measu emen consis s o a ligh - igh
clima e chambe con aining a single SiPM connec ed o he eadou elec onics. The ligh o an
LED connec ed o a pulse gene a o is di ec ed on o he ac i e su ace o he SiPM by an op ical
ibe , and he ampli ie ou pu signal wa e o ms a e acqui ed by a digi al oscilloscope, ope a ed
a 10 GS/s. The ou pu cha ge was measu ed by in eg a ing he signal wa e o m wi hin a 200 ns
window, simila ly o he analysis o es beam da a.
To ob ain a good sepa a ion in he cha ge spec um be ween peaks co esponding o di e en
numbe o pho oelec ons, he clima e chambe empe a u e was se o 0
◦
C o educe he SiPM
–6–
2022 JINST 17 P01038
Figu e 5
. S anda d de ia ion o he di e ence be ween lase pulse and SiPM signal, a a gi en h eshold
ac ion, as unc ion o applied bias ol age.
he mal noise. In o de o ope a e he SiPM a he same gain as a oom empe a u e du ing he es
beam, he bias ol age had o be adjus ed o accoun o he b eakdown ol age (
𝑉b eak
) dependence
on empe a u e, keeping ixed he o e - ol age. The
𝑉b eak
was de e mined a 0
◦
C empe a u e by
acqui ing he V-I cu e wi h a Keysigh B2901A sou ce me e . In a V-log(I) plo , he in e sec ion o he
linea i s o he da k cu en egion and he b eakdown egion p o ides he sough ol age, yielding a
𝑉b eak
o 37.35 V. A cha ge spec um, shown in igu e 6, was acqui ed and he peaks i ed wi h a sum
o mul iple Gaussian unc ions. The a e age dis ance be ween wo adjacen peaks co esponds o he
signal gene a ed by 1 p.e. The esul ing cha ge p oduced by a single pho oelec on is 3.2±0.2pC.
6 Tes beam measu emen s
6.1 Tes beam se up
Tes s wi h an elec on beam ha e been conduc ed a he Beam Tes Facili y (BTF) o Labo a o i
Nazionali di F asca i. The BTF is a beam ans e line designed o he op imised, s ochas ic
p oduc ion o single elec ons/posi ons o de ec o calib a ion pu poses. Elec on and posi on
beams a e c ea ed in he ene gy ange o 25–500 MeV wi h an ene gy sp ead o 1% and a epe i ion
a e a ying be ween 10 and 40 Hz. The ypical spo size can a y wi hin (1–25) mm in
𝑦
and
(1–55) mm in
𝑥
and he di e gence wi hin 1–2 m ad. Beam cha ac e is ics (spo size, di e gence,
momen um esolu ion) a e dependen s ongly on he mul iplici y (numbe o pa icles/bunch) and
ene gy eques ed. Fo he es beam he chosen con igu a ion was an elec on beam o 450 MeV
ene gy wi h an a e age pa icle mul iplici y pe bunch o 1.8 and a spo size o
𝜎𝑥=
1
.
4mm and
𝜎𝑦=
0
.
8mm, as e alua ed a he beam pipe exi [
7
]. The beam spo size on he iles unde es , due
o he dis ance om he beam pipe exi , was o ew mm2.
Du ing he es beam campaign he ou iles equipped wi h Type 2 FEE we e hos ed in o a
ligh - igh box ha ac ed also as a Fa aday cage. The sys em, composed by he ou iles and he box,
–7–
2022 JINST 17 P01038
Figu e 15. Posi ions o he beam on he mini-module du ing he scan pe o med a he BTF es beam.
Figu e 16. Cosmic ay se -up wi h he ou iles piled up. The iles a e labelled as in able 1.
– 14 –

2022 JINST 17 P01038
Table 4
. Resul s o he scan o e he mini-module. The poin s used du ing he scan a e shown in igu e 15.
Fo each o hem he posi ions wi h espec o he (0,0) coo dina e a he mini-module cen e, he a e age
ime a i al, he esolu ion o he ime a i al, and he ligh yield a e shown. The ime esolu ion is al eady
co ec ed o he
𝑇0
ime ji e , while he con e sion o he ligh yield in pho o-elec ons is pe o med exploi ing
he calib a ion desc ibed in sec ion 5.
Tile Label Posi ion A e age a i al ime a i al ime esolu ion ligh yield
n. [cm,cm] [ns] [ps] [N p.e.]
1 A [−7.5,7.5]8.93 ±0.003 226 ±2 230 ±20
1 B [−3.5,7.5]8.87 ±0.003 219 ±3 250 ±21
1 C [−0.5,7.5]8.82 ±0.003 210 ±1 260 ±20
1 D [−3.5,3.5]8.572 ±0.003 243 ±3 300 ±30
1 E [−1.5,1.5]7.992 ±0.003 228 ±3 520 ±80
2 A [7.5,7.5]8.696 ±0.003 237 ±3 186 ±16
2 B [3.5,7.5]8.615 ±0.003 226 ±3 205 ±20
2 C [0.5,7.5]8.541 ±0.003 222 ±3 217 ±20
2 D [3.5,3.5]8.468 ±0.003 227 ±3 263 ±30
2 E [1.5,1.5]8.542 ±0.003 223 ±3 640 ±110
3 A [7.5,−7.5]9.188 ±0.003 229 ±2 207 ±18
3 B [3.5,−7.5]8.991 ±0.007 234 ±7 230 ±22
3 C [0.5,−7.5]8.943 ±0.007 239 ±6 231 ±18
3 D [3.5,−3.5]8.797 ±0.003 237 ±3 358 ±44
3 E [1.5,−1.5]7.87 ±0.003 227 ±3 680 ±200
4 A [−7.5,−7.5]10.231 ±0.003 248 ±2 138 ±13
4 B [−3.5,−7.5]10.154 ±0.003 247 ±2 143 ±14
4 C [−0.5,−7.5]10.172 ±0.003 245 ±3 141 ±13
4 D [−3.5,−3.5]9.927 ±0.003 230 ±3 183 ±20
4 E [−1.5,−1.5]9.898 ±0.003 207 ±3 397 ±78
A oy Mon eCa lo simula ion has been de eloped o es ima e sys ema ic e ec s due o he
cosmics angula dis ibu ion, assuming he widely used
cos2𝜃𝑑Ω
angula dis ibu ion [
8
]. The
angula dis ibu ion o cosmic ays igge ed by he ex e nal iles is shown in igu e 17 oge he wi h
he dis ibu ions o he es ima ed ime-o - ligh be ween he cen al ones. The spa ial dis ibu ion o
he impac poin in one o he igge and in one o he cen al iles is also shown. As a consequence
o he cosmic ays angula dis ibu ion, he ime-o - ligh be ween he cen al iles has an ms o
11 ps, ha will be neglec ed in he ollowing analysis. T igge ed cosmic ays a e ocused in he
cen e o he inne iles, and e en hough impinging on he en i e su ace, en imes mo e e en s
c ossing he cen al a ea a e de ec ed wi h espec o pe iphe al zones. Fo he ex e nal iles, used as
igge , he lux is mo e uni o m, a he le el o ±20%.
Fo he analysis o he digi ized signals, baseline alues ha e been es ima ed o each ile,
a e aging he i s 150 samples (co esponding o 30 ns), and hen sub ac ed. F om he s udy o
baseline dis ibu ions, simila elec onics noise alues as hose obse ed a he es beam, shown in
igu e 11, ha e been in e ed. The signals o he ou iles ha e been disc imina ed a 20% o hei
– 15 –
2022 JINST 17 P01038
HThe a
En ies 9930623
Mean 0.2351
RMS 0.1113
( ad)θ
0 0.2 0.4 0.6 0.8
0
50
100
150
200
250
300
3
10×HThe a
En ies 9930623
Mean 0.2351
RMS 0.1113
H o
En ies 9930623
Mean 0.3571
RMS 0.01052
Time-o - ligh (ns)
0.32 0.34 0.36 0.38 0.4 0.42 0.44
0
100
200
300
400
500
600
700
3
10×H o
En ies 9930623
Mean 0.3571
RMS 0.01052
X (cm)
0 2 4 6 8 10 12 14
Y (cm)
0
2
4
6
8
10
12
14
9500
10000
10500
11000
11500
12000
Impac poin on igge ile 1
X (cm)
0 2 4 6 8 10 12 14
Y (cm)
0
2
4
6
8
10
12
14
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
22000
24000
Impac poin on es ile 1
Figu e 17
. Cosmic ays simula ion: dis ibu ion o he zeni h angle,
𝜃
( op le ), es ima ed ime-o - ligh
be ween he cen al iles ( op igh ), impac poin spa ial dis ibu ion o one o he ex e nal (bo om le ) and
one o he in e nal (bo om igh ) iles.
ampli udes and he ime esolu ion has been es ima ed using he ime-o - ligh be ween he cen al
iles, by i ing he dis ibu ion wi h a Gaussian unc ion and di iding i s sigma by
√2
. E en s wi h
signal ampli udes lowe han 50 mV o highe han 950 mV ( he digi ize has 1 V ange) in ei he o
he cen al iles ha e been disca ded.
The measu ed ime esolu ions wi h he ou di e en FEE ypes a e epo ed in igu e 18
o a bias ol age anging om 39 V o 42.5 V a a empe a u e be ween 22 and 26
◦
C. The bes
pe o mance is ob ained wi h Type 1 FEE (
𝜎∼
230 ps o 1 V o e - ol age), while he wo s
wi h Type 4; he o he wo ypes ha e esolu ions a ound 260 ps. Fo a be e unde s anding, in
able 5 he ampli ude Mos P obable Value (MPV, ob ained by means o a Landau i ) and he ise
ime ( om 10% o 90% o he ampli ude) a e epo ed o he signals acqui ed a 41.5 V wi h he
di e en elec onics on ile 4: Type 1 elec onics is he as es one, bu no he one wi h he g ea es
ampli ica ion. Wa e o m examples acqui ed on ile 4 wi h he ou di e en FEEs a a bias ol age
o 41.5 V a e shown in igu e 4. Fo sake o compa ison, he a i al imes in he iles ha e been
es ima ed also wi h he same algo i hm used o he es beam da a analysis. The di e ence in ime
esolu ions o mos o he measu emen s is lowe han 5%, which is aken as a sys ema ic e o .
Table 5. Tile 4 signal cha ac e is ics a 41.5 V bias ol age using he ou di e en elec onics ypes.
Elec onics ype Ampli ude MPV (mV) Rise ime (ns)
Type 1 281.6±0.8 5.4±0.1
Type 2 259.8±0.7 10.6±0.1
Type 3 170.5±0.8 6.5±0.1
Type 4 507.7±1.5 5.7±0.1
I is wo h men ioning he e ha he ime esolu ions epo ed in his sec ion a e expec ed o
be wo se han hose measu ed a he es beam, as a consequence o he ac ha cosmic ays a e
– 16 –
2022 JINST 17 P01038
Vbias (V)
38.5 39 39.5 40 40.5 41 41.5 42 42.5 43
Time esolu ion (ps)
150
200
250
300
350
400
450
500
TYPE 1
TYPE 2
TYPE 3
TYPE 4
Figu e 18
. Time esolu ion measu ed using cosmic ays wi h he ou di e en elec onics as a unc ion o he
SiPM bias ol age.
igge ed on a la ge a ea and luc ua ions on he ligh collec ion ime play a mo e impo an ole. To
es ima e he o e all ime esolu ion o an uni o m illumina ion o he iles unde es , da a ha e been
acqui ed also igge ing on he cen al iles, pu a a mu ual dis ance o 30 cm, in o de o ep oduce
he dis ibu ion shown a bo om le o igu e 17. The measu ed ime esolu ion wi h Type 2 FEE
is 306 ps, wi h a 10% sys ema ic e o om he compa ison be ween he wo employed analysis
me hods. This alue has o be compa ed wi h
∼
220 ps measu ed wi h he ocused beam a BTF
acili y and ∼260 ps measu ed wi h ocused cosmic ays as bo om igh o igu e 17.
P o i ing o da a acqui ed by igge ing on he coincidence o he cen al iles a 30 cm dis ance,
oge he wi h hose acqui ed o he ime esolu ion measu emen s, we ha e compa ed he MPV
o he signal ampli ude dis ibu ion o he ou di e en iles a he same condi ions: Type 2 FEE,
𝑉bias =
41
.
5V and (almos ) uni o m cosmic ays impac poin dis ibu ion (bo om le o igu e 17).
The measu ed alues a e epo ed in able 6, whe e he same no a ion o he es beam o he ile
iden i ica ion has been used, o ligh yield compa ison. The bes ligh yield is ob ained o iles 1
and 3, while wo se esul s a e ob ained o ile 2 (wi hou slo s o he SiPMs) and o ile 4 ( e lec ing
coa ing ob ained by pain ing a he han e ching). Simila conclusions can be d awn om es beam
da a, as epo ed on able 4, whe e ligh yields can, o ins ance, be compa ed o elec ons c ossing
he cen e o he iles (poin A).
Fo measu ing he e iciency, wo addi ional iles,
(
9
×
9
)cm2
wide, ha e been added a he wo
ex emi ies o he se -up, well inside he a ea o he iles unde es . Thei disc imina ed signals
ha e been added o he igge in coincidence wi h he wo ex e nal iles. In addi ion, iles 2 and 4,
as well as iles 3 and 1, ha e been pu in close con ac each o he , o ha e all he ou iles unde
es wi hin a dis ance o abou 10 cm. Fo he e iciency es ima ion o iles 3 and 4, a signal abo e
30 mV in a 30 ns ime window wi h espec o he igge is equi ed in he o he h ee iles; he
– 17 –
2022 JINST 17 P01038
Table 6
. MPV o he signal ampli ude dis ibu ion o he ou iles equipped wi h Type 2 FEE a
𝑉bias =
41
.
5V.
MPV (mV)
Tile 1 461.7±2.0
Tile 2 356.4±1.2
Tile 3 468.3±1.6
Tile 4 261.7±1.1
ile is conside ed e icien i a signal abo e 30 mV has been eco ded. In igu e 19 he measu ed
e iciencies as a unc ion o
𝑉bias
a e shown o Tiles 3 and 4. Fo
𝑉bias >
39
.
5V (mo e han 1 V
o e - ol age) e iciency alues g ea e ha 99.8 % ha e been measu ed o bo h iles. Gi en he use
o he cosmic ays wi hou acking de ices o e en econs uc ion, we assume his alue as a lowe
limi . Simila alues ha e been ob ained o Tiles 1 and 2, exploi ing he same se -up wi h Tiles 3
and 4 in he igge .
Vbias (V)
38 38.5 39 39.5 40 40.5 41 41.5 42 42.5 43
E iciency (%)
98
98.2
98.4
98.6
98.8
99
99.2
99.4
99.6
99.8
100
Tile 4
Tile 3
Tile 2
Tile 1
Figu e 19
. E iciency alues measu ed o Tiles 3 and 4 on cosmic ays as a unc ion o
𝑉bias
. A h eshold o
30 mV on Type 2 FEE ou pu has been applied.
The e iciency alues epo ed abo e ha e been measu ed wi hou ime cu s on he signals o he
es ed iles; plas ic scin illa o s howe e a e o en conside ed o use as e o de ec o s wi h e y igh
cu s on hei signal a i al imes. We also pe o med he e o e a dedica ed s udy on he e iciency
loss as a unc ion o a cu on he a i al ime using he ime-o - ligh be ween he cen al iles in he
cosmic ay se -up shown in igu e 16. The pe cen age o e en s o which he ime-o - ligh (TOF) is
ou side o a gi en cu is shown in igu e 20 in e ms o
𝜎TOF
. Less han 5% o he e en s a e cu
ou side o 2𝜎(0.5% ou side o 3𝜎).
– 18 –
2022 JINST 17 P01038
)σN (
1 1.5 2 2.5 3 3.5 4
(%)∈ ∆
-1
10
1
10
Figu e 20
. Pe cen age o e en s (
Δ𝜖
) cu symme ically a
𝑁×𝜎
on he dis ibu ion o he ime-o - ligh
be ween he cen al iles in he cosmic ay se -up.
8 Simula ion
The ha dwa e R&D ac i i y has been complemen ed by a de ailed FLUKA [
9
] simula ion o he
combined esponse o he ile and o he pho o-senso s o a minimum ionizing pa icle. The FLUKA
package ( e sion 2020.0.6) has been used wi h Flai [
10
] ( e sion 2.3.0) as g aphical use in e ace.
A squa ed
(
15
×
15
)
cm
2
ile, made o EJ200 scin illa o and ead by ou
(
6
×
6
)
mm
2
Hamama su
SiPMs a he co ne s has been simula ed. Figu e 21 shows a ende ing o he ile geome y and a
de ailed iew o he SiPM placed in i s slo .
Figu e 21
. Rende ing o he ile geome y (le ) used in FLUKA simula ions and close-up o SiPM slo
( igh ).
The EJ200 scin illa o p ope ies (a enua ion leng h, scin illa ion e iciency, emission spec um,
aise/decay imes) and he pho o-de ec ion e iciency e sus wa eleng h o he SiPMs used du ing
es s ha e been implemen ed. Also he glue a ound he SiPMs wi h i s op ical p ope ies has been
– 19 –

2022 JINST 17 P01038
aken in o accoun . The e iciency o he op ical coupling was ixed o 95%. Pho ons hi ing he
𝑇𝑖𝑂2
coa ing unde go o di use e lec ion wi h 90% e lec i i y. The SiPM ou pu is calcula ed
based on he pho ons eaching he SiPM window wi h an empi ical esponse unc ion: o each
pho oelec on an ou pu signal is compu ed and he ou pu signal wa e o m is p oduced summing
o e all pho oelec ons. The ile ou pu signal is hen ob ained by adding all ou SiPMs wa e o ms.
We simula ed he ile esponse o an elec on beam wi h ene gy and ocusing dimensions
equi alen o he one used du ing he es beam measu emen campaign, in o de o pe o m a di ec
compa ison. Simula ed signals om he iles ha e been disc imina ed a 20% o hei ampli udes and
he co esponding imes eco ded. The con ibu ion o he ime ji e due he SiPM and Type 2 FEE
esponse has been aken in o accoun by smea ing he a i al imes by a gaussian unc ion acco ding
o he measu emen s epo ed in sec ion 4. The ime esolu ion has been de e mined by i ing he
esul ing dis ibu ion wi h a Gaussian unc ion. Figu e 22 shows he dis ibu ion o de ec ed pho ons
o a sample o 20k e en s, wi h he beam passing h ough he ile cen e : a MPV o 222
±
12 p.e
is measu ed, which is in good ag eemen wi h he es beam measu ed alue o 230
±
20 p.e ( see
able 4). The simula ed ime esolu ion wi h a 20% h eshold is 215
±
1ps, in easonable ag eemen
wi h he measu ed alue ( able 4).
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2
ns
0
20
40
60
80
100
120
N
En ies 19945
Mean 0.001524± 1.134
S d De 0.001078± 0.2153
Unde low 0
O e low 0
/ nd
2
χ 1134 / 24
Cons an 0.9± 110.4
Mean 0.001± 1.132
Sigma 0.0008± 0.2042
Time dis ibu ion
Figu e 22
. Dis ibu ion o he numbe o de ec ed pho o-elec ons (le ) and o he ile esponse ime ( igh )
wi h simula ed elec on beam e en s.
Simila ly we simula ed he ile esponse o cosmic muons wi h a
𝑐𝑜𝑠2𝜃𝑑Ω
angula dis ibu ion
as desc ibed in sec ion 7. Figu e 23 shows he dis ibu ion o de ec ed pho ons (le ) and he ime
dis ibu ion ( igh ) o a sample o 20k e en s gene a ed acco ding o he spa ial dis ibu ion shown
in igu e 17 (bo om igh ). The ile ime esolu ion wo sen wi h espec o he simula ed elec on
beam da a, esul ing in 258
±
1ps, which is in ag eemen wi h he esul s obse ed in labo a o y
measu emen s wi h Type 2 FEE, shown in igu e 18.
Finally, a uni o m cosmic muon dis ibu ion was simula ed, shown in igu e 24. In his case he
ime esolu ion is 282 ±1ps, in good ag eemen wi h he measu ed alue.
Table 7shows he compa ison be ween da a and simula ion o he ime esolu ion measu ed wi h
he Tile 1 illumina ed wi h: i) an elec on beam in posi ions A,B,D as in igu e 15; ii) cosmic ays.
9 Conclusions
In his pape he pe o mances o ou
(
150
×
150
×
10
)
mm
3
scin illa ing iles, each ead ou by ou
SiPMs Hamama su S14160-6050HS wi h
(
6
×
6
)
mm
2
ac i e a ea, ha e been in es iga ed in e ms o
ligh yield, ime esolu ion and e iciency. Di e en cons uc ion echniques ha e also been compa ed.
– 20 –
2022 JINST 17 P01038
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
ns
0
200
400
600
800
1000
1200
1400
1600
N
En ies 19968
Mean 0.001826± 1.007
S d De 0.001291± 0.258
Unde low 2
O e low 0
/ nd
2
χ 149.3 / 36
Cons an 13.2± 1557
Mean 0.002± 1.005
Sigma 0.001± 0.254
Time dis ibu ion
Figu e 23
. Dis ibu ion o he numbe o de ec ed pho o-elec ons (le ) and o he ile esponse ime ( igh )
wi h simula ed cosmic muons e en s.
En ies 19999
Mean 284.7
S d De 79.25
Unde low 173
O e low 18
/ nd
2
χ 1479 / 94
Cons an 104.1± 9296
MPV 0.3± 243.3
Sigma 0.14± 16.23
100 200 300 400 500 600 700 800 900
n. o phel.
0
200
400
600
800
1000
1200
1400
1600
n. o e-
En ies 19999
Mean 284.7
S d De 79.25
Unde low 173
O e low 18
/ nd
2
χ 1479 / 94
Cons an 104.1± 9296
MPV 0.3± 243.3
Sigma 0.14± 16.23
n. o pho oel. (cosm.mu)
6−4−2−0 2 4 6x (cm)
6−
4−
2−
0
2
4
6
y (cm)
10
15
20
25
30
35
40
45
n en ies
Cosmic posi ion
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
ns
0
200
400
600
800
1000
N
En ies 19909
Mean 0.001999± 0.9424
S d De 0.001413± 0.282
/ nd
2
χ 201.2 / 36
Cons an 9.6± 1127
Mean 0.0020± 0.9407
Sigma 0.0013± 0.2792
Time dis ibu ion
Figu e 24
. Tile simula ion wi h an uni o m muon lux: dis ibu ion o he numbe o de ec ed pho o-elec ons
( op), impac poin spa ial dis ibu ion (bo om le ) and ile esponse ime (bo om igh ).
Tiles 1 (EJ200 scin illa o pain ed wi h e lec ing pain ing) and 3 (UNIPLAST scin illa o wi h
e lec i e laye ob ained by chemical e ching) ha e he bes ligh yield, mo e han 200 pho o-elec ons
o minimum ionizing pa icles impinging on he cen e o he ile. A wo se pe o mance is ob ained
wi h Tile 2 (EJ200 scin illa o wi h SiPMs glued on cu co ne s a he han eng a ed inside he ile)
and Tile 4 (UNIPLAST scin illa o pain ed wi h e lec i e pain ing).
– 21 –
2022 JINST 17 P01038
Table 7
. Compa ison be ween da a and simula ion o he ime esolu ion measu ed wi h he Tile 1 illumina ed
wi h: i) an elec on beam in posi ions A,B,D as in igu e 15; ii) cosmic ays uni o mly dis ibu ed.
posi ion A posi ion B posi ion D cosmic ays
𝜎𝑡(da a, ps) (226 ±2) (219 ±3) (243 ±3) (306 ±30)
𝜎𝑡(simula ion, ps) (204 ±1) (203 ±1) (225 ±1) (282 ±1)
Despi e he qui e di e en ligh yield alues, he ou iles show a simila pe o mance in
e ms o ime esolu ion, as measu ed in he BTF es beam. A possible explana ion is ha he
dependence o he ime esolu ion on he ligh yield is elaxed o a su icien ly high numbe (
>
100)
o pho o-elec ons.
By means o cosmic muons, we ha e measu ed he o e all ime esolu ion o an uni o m
illumina ion o he ile, which is 306 ps wi h a sys ema ic e o o he o de o 10% om he
compa ison o he esul s wi h he wo di e en conside ed analyses. In case o a uni o m
illumina ion o he ile, a wo se ime esolu ion is expec ed because o he con ibu ion due o he
ligh p opaga ion om he pa icle impac poin o he nea es SiPM. Wi h he cosmic ay se -up,
e iciency alues g ea e han 99.8 % ha e been obse ed o all he iles.
The measu ed ligh yield and ime esolu ion alues ha e been c oss-checked by means o a
FLUKA based Mon eCa lo simula ion, which can be u he used o es ima e he pe o mances o
iles wi h di e en geome ies. The ag eemen wi hin da a and Mon eca lo is good, a a le el be e
han 10% o all he da a samples conside ed: es beam elec ons as well cosmic ays, bo h wi h a
ocused and an uni o m illumina ions.
Di e en F on -End elec onics ha e been also es ed; he bes iming pe o mances a e ob ained
wi h he cu en con eyo con igu a ion.
This echnology is he e o e p o en o be sui able o la ge a ea scin illa ing de ec o s when
ime esolu ion o 200–300 ps and e y high e iciency a e equi ed.
Acknowledgmen s
We a e indeb ed o B. Ponzio (INFN-LNF) o his suppo o he ins alla ion o he emo e con ol
so wa e o he mo emen o he igid ame a he BTF es beam. We a e g a e ul o T. Napoli ano
and he SPCM se ice o LNF o he ealisa ion o he mechanical suppo s used o he es s.
Finally we acknoledge p o esso Y. Kudenko (INR-Moscow) o his ui ul sugges ions. This p ojec
has ecei ed unding om he Eu opean Union’s Ho izon 2020 Resea ch and Inno a ion p og amme
unde G an Ag eemen No. 101004761.
Re e ences
[1] G. Bonda enko e al., Limi ed Geige -mode mic ocell silicon pho odiode: New esul s,Nucl. Ins um.
Me h. A 442 (2000) 187.
[2] F. Simon, C. Soldne and C. Jo am, Di ec coupling o SiPMs o scin illa o iles o imaging
calo ime y and igge ing, in p oceedings o he IEEE Nuclea Science Symposuim & Medical
Imaging Con e ence, Knox ille, TN, U.S.A., 30 Oc obe –6 No embe 2010, pp. 1703–1706
[a Xi :1011.5033].
– 22 –
2022 JINST 17 P01038
[3] O. Poo h, T. Rade mache , S. Weinga en and L. Weins ock, Scin illa o iles ead ou wi h silicon
pho omul iplie s,2015 JINST 10 T10007.
[4] S.H. Chang, D.H. Kim, M.A. Khan, D.J. Kong, J.S. Suh and Y.D. Oh, P oduc ion o ex uded ine
scin illa o s ips,J. Ko ean Phys. Soc. 53 (2008) 3178.
[5] W. Baldini e al., SHADOWS (Sea ch o Hidden And Da k Objec s Wi h he SPS),
a Xi :2110.08025.
[6] Y.G. Kudenko, L.S. Li enbe g, V.A. Maya sky, O.V. Minee and N.V. E sho , Ex uded plas ic
coun e s wi h WLS ibe eadou ,Nucl. Ins um. Me h. A 469 (2001) 340.
[7]
B. Buonomo, C. Di Giulio, L.G. Fogge a and P. Valen e, A ha dwa e and so wa e o e iew on he new
BTF ans e se p o ile moni o , in P oceedings o he 5 h In e na ional Beam Ins umen a ion
Con e ence, Ba celona, Spain, 11–15 Sep embe 2016, pp. 818–821.
[8] Pa icle Da a G oup collabo a ion, Re iew o Pa icle Physics,PTEP 2020 (2020) 083C01.
[9] T.T. Böhlen, F. Ce u i, M.P.W. Chin, A. Fassò, A. Fe a i, P.G. O ega e al., The FLUKA Code:
De elopmen s and Challenges o High Ene gy and Medical Applica ions,Nucl. Da a Shee s 120
(2014) 211.
[10] V. Vlachoudis, Flai : A powe ul bu use iendly g aphical in e ace o FLUKA, in p oceedings o
he In e na ional Con e ence on Ma hema ics, Compu a ional Me hods & Reac o Physics, Sa a oga
Sp ings, NY, U.S.A., 3–7 May 2009.
– 23 –