Design and status of the Mu2e crystal calorimeter · Mu2e experiment design The Mu2e Calorimeter,...
Transcript of Design and status of the Mu2e crystal calorimeter · Mu2e experiment design The Mu2e Calorimeter,...
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Design and status of the Mu2e crystal calorimeter
Raffaella Donghia LNF-INFN and Roma Tre university
On behalf of the Mu2e calorimeter group
May , 2016 XVII LNF Spring School
"Bruno Touschek”
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Talk overview
Mu2e Electromagnetic calorimeter • Requirements • Components • Single Channel Tests • “Module-0” performance • Production phase
The Mu2e Calorimeter, R.Donghia 1 May 10, 2018
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Mu2e experiment design
The Mu2e Calorimeter, R.Donghia 2
PS TS
DS
May 10, 2018
Detector Solenoid: stopping target and detectors • Stops μ- on Al foils
• Events reconstructed by detectors optimized for 105 MeV/c momentum
• CLFV strongly suppressed: Branching Ratio ≤10-54 à Observation would indicate New Physics
• CLFV@Mu2e:μ- e conversion in a nucleus field à discovery sensitivity to many NP models
• Goal: μ-e conversion in the presence of a nucleus
< 8.4 x 10-17
Nuclear captures of muonic Al atoms
µe Al
ECE = 104.97 MeV
(@ 90% CL, with ~ 1018 stopped-µ)
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Calorimeter requirements
The Mu2e Calorimeter, R.Donghia 3 May 10, 2018
• σE/E = 𝓞(5%) for CE • σT < 500 ps for CE • σX,Y ≤ 1 cm
• Fast scintillation signals (τ
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Calorimeter Design
The Mu2e Calorimeter, R.Donghia
2 annular disks with 674 undoped CsI (34 x 34 x 200) mm3
square crystals/each disk
o RIN = 374 mm, ROUT = 660 mm o Depth = 10 X0 (200 mm), Distance 70 cm o Readout: 2 UV-extended SiPMs/crystal o FEE on the SiPMs , Digital readout on crates o RA source for energy calibration o Laser system for monitoring
4 May 10, 2018
BETTER PICTURE!!
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Simulated performance
The Mu2e Calorimeter, R.Donghia 5 May 10, 2018
Simulation of CsI+SiPM performanceSimulation includes full background and digitization and cluster-finding, with split-off and pileup recovery
Energy resolution
Dependence on LRUand photostatistics
Specification is LRU
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Small prototype: Test Beam
The Mu2e Calorimeter, R.Donghia 6 May 10, 2018
• Small prototype tested @ BTF (Frascati) in April 2015, 80-120 MeV e-
• 3×3 array of 30×30×200 mm2 undoped CsI crystals coupled to one Hamamatsu SiPM array (12x12) mm2 with Silicon optical grease
• DAQ readout: 250 Msps CAEN V1720 WF Digitizer
JINST 12 (2017) P05007
FOTO matrice
Log-normal fit
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1 year long R&D phase for the final test of the option CsI + UV extended SiPM
72 crystals + 150 SiPM + 150 FEE chips completed in 2016
Small prototype: Time and Energy resolution
The Mu2e Calorimeter, R.Donghia 7 May 10, 2018
Significant leakage contribution due to block dimensions w.r.t. the shower
σT ~ 110 ps at 100 MeV σE ~ 6.5% at 100 MeV
JINST 12 (2017) P05007
PRE-PRODUCTION
hEntries 0Mean 0RMS 0
Energy [GeV]0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
[ns]
tσ
0
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0.1
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hEntries 0Mean 0RMS 0
/ ndf 2χ 38 / 17a 0.00015± 0.0049 b 0.0033± 0.087
/ ndf 2χ 38 / 17a 0.00015± 0.0049 b 0.0033± 0.087
b⊕ = a/E tσ
Single crystal @ 0 degAll crystals above 10 MeV @ 0 deg
CosmicsNeighboring crystals @ 50 degSingle crystal @ 50 deg
Most energetic crystal @ 50 degAll crystals above 10 MeV @ 50 deg
Figure 24. Time resolution summary plot.
leakage due to the small dimensions of the prototype. The time resolution �t as a function of theenergy deposition has been measured using three di�erent techniques that consistently show that�t ranges from 250 ps at 22 MeV to about 120 ps above 50 MeV. These results satisfy the Mu2erequirements and also significantly improve the timing resolution achievable when using undopedCsI at these low energies compared to present results in literature [6, 7] thanks to the use of SiPMand high frequency waveform digitizer boards.
Acknowledgment
The authors express their sincere thanks to the operating sta� of the Beam Test Facility in Frascati(Italy), for providing us a good quality electron beam, and the technical sta� of the participatinginstitutions. This work was supported by the US Department of Energy; the Italian Istituto Nazionaledi Fisica Nucleare; the US National Science Foundation; the Ministry of Education and Science ofthe Russian Federation; the Thousand Talents Plan of China; the Helmholtz Association of Germany;and the EU Horizon 2020 Research and Innovation Program under the Marie Sklodowska-CurieGrant Agreement No.690385.
References
[1] L. Bartoszek et al., Mu2e Technical Design Report, 3rd ed. arXiv:1501.05241 [physics.ins-det],2014.
[2] N. Atanov et al., Design and status of the Mu2e electromagnetic calorimeter, NIM A 824, 695 - 698,2016.
[3] K. A. Olive et al, Review of Particle Physics, Chin. Phys. 14, 2014.
Total energy [GeV]0.07 0.075 0.08 0.085 0.09 0.095 0.1 0.105
/E [%
]Eσ
44.5
55.5
66.5
77.5
88.5
9
/ ndf 2χ 2.866 / 3a 0.3253± 1.38 b 1.092± 4.911
/ ndf 2χ 2.866 / 3a 0.3253± 1.38 b 1.092± 4.911
data
Monte Carlo
b⊕ E [GeV]
a = EEσ
Figure 17. Energy resolution obtained from the data (black) taken at 0 degrees compared with the MonteCarlo (red).
Figure 18. Distribution of reconstructed energy obtained from the data overlaid with the Monte Carlo forthe run with beam energy of 100 MeV and 50 degrees incidence angle. Blue line represents a fit to the datawith a log-normal function.
obtained with this technique, Method 1 was used to measure the time resolution in the same events.Figure 22 shows the time residual between tcrystal(1,1) and tscint. Subtracting in quadrature the tscintjitter of 100 ps results in a time resolution of about 209 ps that is compatible with the result obtainedwith Method 3.
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/MeVpeN100 110 120 130 140 150 160 170 180 190 200
Entr
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LRU (%)0 1 2 3 4 5 6 7 8 9 10
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(%)µ/σ10 11 12 13 14 15 16 17 18 19 20
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Saint Gobain
F/T (%)60 65 70 75 80 85 90 95 100 105
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Pre-production Crystals
The Mu2e Calorimeter, R.Donghia 8 May 10, 2018
• 24 crystals from three different vendors: SICCAS, Amcrys, Saint Gobain • Optical properties tested with 511 keV γ’s along the crystal axis • Crystals wrapped with 150 µm of Tyvek and coupled to an UV-extended PMT
Energy resolution
Light Yield Longitudinal Resp. Uniformity
Q(200 ns)/Q(3000 ns)
RMS/MEAN of Light
Output values
along axis
Fast/Total
Un-doped CsI crystals perform well
• Excellent LRU and LY: -100 pe/MeV with PMT readout -LRU < 5% § τ of 30 ns with small slow component
§ Radiation hardness OK
Smaller than 40% LY loss @ 100 krad
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Entries 102900Mean 90.04Mean y 33.18RMS 63.51RMS y 33.26
Time [ns]0 50 100 150 200
Am
plitu
de [m
V]
020406080
100120140160
Entries 102900Mean 90.04Mean y 33.18RMS 63.51RMS y 33.26
Entries 102900Mean 90.09Mean y 60.63RMS 63.51RMS y 110.6
Time [ns]0 50 100 150 200
Am
plitu
de [m
V]
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100
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500 Entries 102900Mean 90.09Mean y 60.63RMS 63.51RMS y 110.6
Pre-production test: SiPMs (1)
The Mu2e Calorimeter, R.Donghia 9 May 10, 2018
Gain spread – vendor 1
• Relative spread at the level of 2%• All tested devices satisfy the requirement
6/19/2017G. Pezzullo @ Calorimeter CRR for CsI and SiPMs14
Vop spread – vendor 1
• 35 devices tested• Relative spread at the level of 0.07%• All Mu2e SiPMs from this vendor satisfy this requirement
6/19/2017G. Pezzullo @ Calorimeter CRR for CsI and SiPMs4
150 sensors: 3×50 Mu2e pre-production SiPMs from Hamamatsu, SenSl and AdvanSiD • 3×35 were fully characterized for all six cells in the array
Operating Voltage
Gain
Mu2e custom silicon photosensors: à 2 arrays of 3 6 x 6 mm2 UV-extended SiPMs: total area (12x18) mm2 The readout series configuration reduces the overall capacitance and allows us to generate faster signals
~ 150 V
i1≈ i2 ≈ i3Ctot ≈ C1/3
6x6 mm2
K1
A1
A1-1
A1-2
Single cell of 6 x 6 mm2
Series of 3 cells
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Module 0
• The outer shell has been initially machined in Lecce. Now in INFN Padova where they have EDM
• Front plate in Lecce• FEE plate in Pisa• FEE holders order out• Crystals being wrapped• SiPM tested• FEE on the way
FabioHappacher7
Module 0
The Mu2e Calorimeter, R.Donghia 10 May 10, 2018
Large EMC prototype: 51 crystals, 102 SiPMs, 102 FEE boards
Mechanics and cooling system similar to the final ones! Goals:
• Integration and assembly procedures • Test beam May 2017, 60-120 MeV e-
(beam perpendicular and @ 50°)
• Work under vacuum, low temperature, irradiation test
3/29-30/2017Fabio Happacher | MDR Review14
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1.91335e+06
128053 93017.6
81310.4
99920.4112888
135539
67022.8 102991 98354.5
103895
108076
123601
151623128720130298
94299.6
88138.3
86969.5
136475 79070.2 127412 110208
103408
134562
111132
134589
103162
10689712596287092.6103181
26479
100319
122841
104284
120963
97679.7
76132.1
106792
79394.9
104968
104676
96822.4107369
98298.7
108205
121208
101734
122820
107887
x [mm]200− 150− 100− 50− 0 50 100 150 200
y[m
m]
200−
150−
100−
50−
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Entries 663136Mean x 0.01988Mean y 0.1337− Std Dev x 62.82Std Dev y 55.23 0 0 0 0 0 0 0 0 0
1
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510
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Entries 663136Mean x 0.01988Mean y 0.1337− Std Dev x 62.82Std Dev y 55.23 0 0 0 0 0 0 0 0 0
Module 0 Energy resolution
The Mu2e Calorimeter, R.Donghia 11 May 10, 2018
σE ~ 5.4 % (entire matrix)
@ Ebeam = 100 MeV
§ Calibration - cosmic rays - beamàcompleted for second
ring around central crystal § Data quality good,
resolution in agreement with 3x3 prototype
Entries 1811
/ ndf 2χ 4.943 / 4
η 0.104± 0.277
σ 0.240± 5.075
µ 0.34± 93.14
N 104.1± 3168
E [MeV]50 60 70 80 90 100 110 120
Ent
ries/
2 M
eV
0
50
100
150
200
250Entries 1811
/ ndf 2χ 4.943 / 4
η 0.104± 0.277
σ 0.240± 5.075
µ 0.34± 93.14
N 104.1± 3168
Orthogonal runEbeam=100 MeV
Orthogonal runEbeam=100 MeV
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Module 0 Time resolution
The Mu2e Calorimeter, R.Donghia 12 May 10, 2018
TimeHist / ndf 2 106.6 / 20
0.0444 0.6526 1.21 17.12 0.7 216.6
N 640.2 8782
t [ns]0 200 400 600 800 1000
Am
plitu
de [m
V]
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50
100
150
200
250
300
350 TimeHist / ndf 2 106.6 / 20
0.0444 0.6526 1.21 17.12 0.7 216.6
N 640.2 8782
Entries 1531
/ ndf 2 19.56 / 15
Constant 7.6 240.9
Mean 0.0049 0.1664
Sigma 0.0035 0.1874
t [ns] 1.5 1 0.5 0 0.5 1 1.5
Ent
ries
/ (0.
075
ns)
0
50
100
150
200
250Entries 1531
/ ndf 2 19.56 / 15
Constant 7.6 240.9
Mean 0.0049 0.1664
Sigma 0.0035 0.1874
Fit Example Central crystal time distribution
(TSiPM 1 – TSiPM2)
σ (T1+T2)/2 ~ 94 ps @ Ebeam = 100 MeV
• Selection on single particle • Log-normal fit on leading edge • Constant Fraction method used à CF = 5%
Δ
ησµ
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Module 0 Results
The Mu2e Calorimeter, R.Donghia 13 May 10, 2018
Test Beam data analysis results satisfy Mu2e requirements à @ 100 MeV
• σE ~ 5.44 ± 0.25 % • σT < 100 ps, both @ 1 GHz and 250
MHz sampling rate à MC simulation still on going
Energy [MeV]0 20 40 60 80 100
[ns]
Tσ
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/ ndf 2χ 1.506 / 4a 0.2903± 6.217 b 0.009087± 0.08504
/ ndf 2χ 1.506 / 4a 0.2903± 6.217 b 0.009087± 0.08504
/ ndf 2χ 1.997 / 2a 0.4899± 4.449 b 0.007553± 0.07
/ ndf 2χ 1.997 / 2a 0.4899± 4.449 b 0.007553± 0.07
Perpendicular Beam
Beam at 50°
0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 [MeV]depE
0123456789
10
[%]
dep
/Eσ
a 0± 0.6
b 0.02119± 0.3277
c 0.2454± 4.006
a 0± 0.6
b 0.02119± 0.3277
c 0.2454± 4.006
�EE
=apE
� bE
� c
σT = a/E + b
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Calorimeter Assembly status
The Mu2e Calorimeter, R.Donghia 14 May 10, 2018
New laboratory built at FNAL. QA tests of all components started on march 2018
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Summary and Conclusions
The Mu2e Calorimeter, R.Donghia 15 May 10, 2018
• The Mu2e calorimeter has concluded its prototyping phase satisfying the Mu2e requirements:
• Un-doped CsI crystals perform well § Excellent LRU and LY 100 pe/MeV ( PMT+Tyvek wrapping ) § τ of 30 ns with negligible slow component § Radiation hardness OK for our purposes: 40% LY loss at 100 krad
• Mu2e SiPMs quality OK, high gain, high PDE, small Idark, small spread inside array • SiPM performance after irradiation OK • SiPM MTTF > 0.6 million hours
• Single calorimeter channel: timing resolution of 215 ps /MIP • Small prototype tested with e- beam
§ Good time and energy resolution achieved @ 100 MeV • Module 0 built and first tests done.
• TB data analysis results satisfies the requirements • Good time and energy resolution achieved @ 100 MeV, in agreement with the small prototype
• Calorimeter production phase started • Detector installation expected for beginning of 2020
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Spares
Raffaella Donghia LNF-INFN and Roma Tre university
On behalf of the Mu2e calorimeter group
May , 2016 XVII LNF Spring School
"Bruno Touschek”
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Charged Lepton Flavor Violation
The Mu2e Calorimeter, R.Donghia 17 May 10, 2018
• CLFV strongly suppressed in SM: Branching Ratio ≤10-54 à Observation would indicate New Physics
• CLFV@Mu2e:μ- e conversion in a nucleus field à discovery sensitivity to many NP models
• Goal: 104 improvement w.r.t. current limit (SINDRUM II)
(@ 90% CL, with ~ 1018 stopped muons in 3 years of running)
μ-e conversion in the presence of a nucleus
< 8.4 x 10-17
Nuclear captures of muonic Al atoms
µe
Al
ECE = mμc2 – Eb – Erecoil= = 104.97 MeV
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Mu2e experiment design
The Mu2e Calorimeter, R.Donghia 18
25 m Production Solenoid / Target • Protons hitting target and
producing mostly π
Transport Solenoid • Selects and transports low
momentum μ-
PS
TS
DS
May 10, 2018
1. Generate low momentum μ- beam
2. Stop the muons in an Al target à trapped in orbit around the nucleus 3. Look for an excess around 105 MeV/c in the electron spectrum
Detector Solenoid: stopping target and detectors • Stops μ- on Al foils • Events reconstructed by detectors optimized
for 105 MeV/c momentum
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Mu2e
Charged Lepton Flavor Violation
The Mu2e Calorimeter, R.Donghia 19 May 10, 2018
• CLFV strongly suppressed in SM: BR ≤10-54 à Observation indicates New Physics
• CLFV@Mu2e:μ- e conversion in a nucleus field à discovery sensitivity on many NP models
• Goal: 104 improvement w.r.t. current limit (SINDRUM II)
(@ 90% CL, with ~ 1018 stopped muons in 3 years of running)
Contact dominated
Loop dominated
μ-e conversion in the presence of a nucleus
< 8 x 10-17
Nuclear captures of muonic Al atoms
µe
Al
arXiv: 1303.4907
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Pre-production test: SiPMs (2)
The Mu2e Calorimeter, R.Donghia 20 May 10, 2018
• 1 sample per vendor has been exposed to neutron flux up to 8.5×1011 n1MeVeq/cm2 (@ 20 °C)
• 5 samples per vendor have been used to estimate the mean time to failure value Requirement: obtain an MTTF of 1 million hours when operating at 0 °C
]2/cm1MeV
Integrated flux [n0 100 200 300 400 500 600 700 800
910
I [m
A]
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• MTTF evaluated operating SiPMs @ 50 °C for 3.5 months
• No dead channels observed MTTF ≥ 6×105 hours
• SiPMs will operate @ 0 °C: a decrease of 10 ˚C in SiPMs temperature corresponds to a Id decrease of 50%
• Lower Vop also helps to decrease the Id
MTTF Neutron test
HamamatsuSenSl AdvanSiD
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SG crystal + Hamamatsu SiPM + FEE Optical coupling in air. • 22Na source
- TRG: small scintillator readout by a PMT - Study distance effect for air-coupling
Single channel slice test
The Mu2e Calorimeter, R.Donghia 21 May 10, 2018
h1Entries 4443222
Mean 145.5
Mean y 10.67
RMS 43.59
RMS y 12.41
Time [ns]80 100 120 140 160 180 200 220
Am
plitu
de [m
V]
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h1Entries 4443222
Mean 145.5
Mean y 10.67
RMS 43.59
RMS y 12.41
h2Entries 4375308
Mean 500
Mean y 2.651
RMS 288.4
RMS y 5.918
h3Entries 4128348
Mean 500
Mean y 2.812
RMS 288.4
RMS y 5.987
Hamamatsu 4 - DIstance from Crystal0 mm1 mm2 mm
onda3-1.3:time {tmean2-tmean3>-40 && tmean2-tmean3120 && charge2
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Single channel Cosmic Rays Test
The Mu2e Calorimeter, R.Donghia 22 May 10, 2018
• TRG time resolution ~ 170 ps • Constant fraction method used • Pulse height correction applied (slewing)
After jitter subtraction: SiPM 1 – σT ~ 330 ps SiPM 2 – σT ~ 340 ps
T(SiPM1 - SiPM2)/2 à ~ 215 ps @ ~ 23 MeV energy deposition
(MIP energy scale from Na22 source peak)
Timing result well compares with old tests: à Reduced light output/SiPM
(22 vs 30 pe/MeV) à 2 SiPMs/crystal à LY of 44 vs 30 à 215 ps (now) vs 250 ps (old).
Entries 727
Constant 6.2± 133.6
Mean 0.0161± 0.1234
Sigma 0.012± 0.429
Time [ns]-3 -2 -1 0 1 2 3
Entr
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/ 25
ps0
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Entries 727
Constant 6.2± 133.6
Mean 0.0161± 0.1234
Sigma 0.012± 0.429
SiPM 1 - SiPM 2Entries 727
Constant 8.6± 185.7
Mean 0.012± -0.297
Sigma 0.0083± 0.3073
Time [ns]-3 -2 -1 0 1 2 3
Entr
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/ 25
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Entries 727
Constant 8.6± 185.7
Mean 0.012± -0.297
Sigma 0.0083± 0.3073
/2Σ(SiPM1 + SiPM2)/2 -
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Pre-production test: Crystals (2)
The Mu2e Calorimeter, R.Donghia 23 May 10, 2018
Few samples per vendor have been exposed both to ionizing dose and neutrons • Irradiation test up to 100 krad • Requirement:
normalized LY after 10/100 krad > 85/60%
• Radiation Induced Noise (RIN) @ 1.8 rad/h required is < 0.6 MeV • All 72 samples tested. All OK apart some Amcrys crystals that do not satisfy the required limit
• Negligible LY and LRU variation after 1.6 x 1012 n1MeV/cm2 integrared flux • Neutron RIN is also smaller than the one from dose
Most crystals have LY larger than 100 p.e./MeV after 100 krad
(40% max. loss), promising a robust CsI calorimeter
85%
60%
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PId
The Mu2e Calorimeter, R.Donghia 24 May 10, 2018 24
With a CRV inefficiency of 10-4 an additional rejection factor of ~ 200 is needed to have < 0.1 fake events from cosmics in the signal window
A rejection factor of 200 can be achieved with ~ 95% efficiency for CE
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Calibration source and laser
25 May 10, 2018
+ cosmics
• Liquid source FC 770 + DT generator: 6 MeV + 2 escape peaks • Laser system to monitor SiPM performance
The Mu2e Calorimeter, R.Donghia
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Calorimeter Trigger
The Mu2e Calorimeter, R.Donghia 26 May 10, 2018
• Calo info can provide additional trigger capabilities in Mu2e: • Calorimeter seeded track finder
• Factorized into 3 steps: hit pre-selection, helix serach and track fit • ε ~ 95% for background rejection of 200
• Standalone calorimeter trigger that uses only calo info • Ε ~ 65% for background rejection 200
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Calorimeter seeded track finder
The Mu2e Calorimeter, R.Donghia 27 May 10, 2018
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Calorimeter radiation damage
The Mu2e Calorimeter, R.Donghia 28 May 10, 2018
• Calorimeter radiation dose driven by beam flash (interaction of proton beam on target)
• Dose from muon capture is x10 smaller • Dose is mainly in the inner radius • Highest dose ~10 krad/year • Highest n flux on crystals ~ 2×1011 n/cm2/year • Highest n flux on SiPM ~ 1011 n1MeVeq/cm2/year •
• Qualify crystals up to ~ 100 krad, 1012 n/cm2
• Qualify SiPM up to ~ 1012 n1MeVeq/cm2
This includes a safety factor of 3 for a 3 year run
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Calorimeter radiation damage
The Mu2e Calorimeter, R.Donghia 29 May 10, 2018
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Three years run Expectation by full Simulation
The Mu2e Calorimeter, R.Donghia 30
Mu2e Collaboration, November 2013
May 10, 2018
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CLFV Lagrangian
The Mu2e Calorimeter, R.Donghia 31
Mu2e Collaboration, November 2013
μN→eN
μ→eγ
μ→eee
Loops dominate for κ > 1
κ
μN→eN
μ→eγ
μ→eee
Λ (
TeV
)
May 10, 2018