RPC 2016: Muography of Puy de Dôme

RPC application in muography and
specific developments
Eve Le Ménédeu (LPC)
on behalf of the TOMUVOL collaboration
RPC 2016 conference
21-26 February 2016, Gent
February 26, 2016
Eve Le Ménédeu
1/17
Outline
1 Context
2 Overview of the experiment
3 Tomuvol detector
4 Performances
5 Data analysis
6 R&D
7 Conclusion
February 26, 2016
Eve Le Ménédeu
2/17
Context
Imaging volcanoes
• Goals: volcanic hazard mitigation, prediction of their future behaviour from
internal structure and past activity
• Several methods are usually used to study the inner structure of volcanoes:
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electrical resistivity tomography → (fluids, alteration, nature of rocks)
gravimetry → density
magnetization → local variation of magnetic field induced by rocks
seismic tomographies → elasticity and seismic waves velocity
• Difficult to access large depth, complex, ill-posed inverse problem and
usually on the volcano itself (resistivity and gravimetry)
Ref: Portal et al., 2015, JVGR, submitted
February 26, 2016
Eve Le Ménédeu
3/17
Context
Tomuvol experiment
• Goal: Proof of principle for imaging volcanoes with atmospheric muons
(muography) using the Puy de Dôme volcano.
• Collaboration: LPC, LMV, IPNL, ESGT
• Steps
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2011-2012: Preliminary campaigns with CALICE GRPCs
2012: Building and commissionning a dedicated detector
2013-2016: Data-taking campaigns with the Tomuvol chambers on Puy de Dôme
Col de Ceyssat
Feb – March 2012
Oct 2014 – Jan 2015
Sept 2015 – Feb 2016
TDF
Nov - Dec 2013
February 26, 2016
Eve Le Ménédeu
Grotte Taillerie
Jan - July 2011
March - April 2016
4/17
Overview of the experiment
Muography
• Principle same as for radiography: a radiation passes through a target and we build a
2D image from its transmittance
• As target is huge (volcano) → use atmospheric muons
Cross kms before decaying
Large energy spectrum: 100 MeV → PeV
Simple trackers and no direct measurement of incoming flux
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Target
y
Distance
Elevation, α
R=1cm
x
Detector
10m
10 mrad
Azimuth, β
z
d=1km
d=1m
Tρ (α,r(α,β)) =
φ(α,r(α,β))
φ0 (α)
5
Z
with
ρ(α,β)dr = F (Tρ )
ρ: density to be determined through integrated density over a direction where F is a bijection (unique solution)
• Advantages:
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Complementary to other, already existing, methods
Remote imaging
Good spatial resolution; well-defined inverse problem
• But (very) high energy muons are rare, in particular for the interesting directions
February 26, 2016
Eve Le Ménédeu
5/17
Overview of the experiment
Objectives
6 hours
ay
1d
eek
1w
100 m
300 m
500 m
1h
1 km
our
h
ont
1m
1 year
2 km
10 years
3 km
• If high resolution wanted, high exposure (Sdet × Time) needed
• Possible compromise between density resolution and angular resolution
depending on physics goal
• Gaseous detectors: reasonable price for large areas
Tomuvol detector
Highly segmented tracker without energy measurement
and particle identification capabilities
February 26, 2016
Eve Le Ménédeu
6/17
Tomuvol detector
Tomuvol detector
• 4 layers of 6 GRPCs made at IPNL, following
CALICE SDHCAL GRPCs
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1 layer ∼ 1 m2
readout cells of 1 cm2 (∼ 40000 cells)
1.2 mm gap
Gas: 93.0% C2 H2 F4 , 5.5% C4 H10 and 1.5% SF6
Nominal HV: ∼ 7.5 kV @ P = 1.013 hPa and
T = 20 ◦ C
• Electronics:
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synchronous at 5 MHz, auto-triggered
very front end: semi-digital Hardroc2 ASICs
from Omega (Palaiseau), 64 channels, low
power consumption (3.5 mW/channel),
3 thresholds
front end: DIF board from LAPP (Annecy)
DAQ
PC
USB2
Ethernet
D
C
C
• Slow control:
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DIF
DIF
DIF
DIF
DIF
DIF
DIF
Eve Le Ménédeu
clock &
D trigger
master
C
C
→ clock, trigger
← readout, busy
DIF
DIF
D
C
C
USB2
DIF
DIF
DIF
DIF
PLC (gas, HV, LV, environmental conditions)
remotely monitored from web interface
February 26, 2016
DIF
DIF
DIF DIF
DIF
DIF
DIF DIF
DIF
DIF
DIF
DCC
7/17
Tomuvol detector
Zoom on GRPCs
1st try with GRPCs from CALICE collaboration for SDHCAL before customization
CALICE SDHCAL GRPCs
TOMUVOL GRPCs
• 6 PCB of 50 × 33 cm2
• 50 × 33 cm2 chambers following
the existing PCB geometry
• Float glass: 0.7 and 1.1 mm
• 1 PCB of 50 × 33 cm2 per chamber
• Independent gas circuit
• Float glass: 2 × 1.1 mm
• 1 DIF for 2 PCB
• Chambers chained by 3 for gas
circulation
• 1 m2 chambers
• Iron cassette
• 1 DIF for each PCB
• Aluminium cassette
Ref: Beaulieu et al., JINST 10 (2015) 10, P10039
February 26, 2016
Eve Le Ménédeu
8/17
Performances
Atmospheric conditions
February 26, 2016
Eve Le Ménédeu
9/17
Performances
4
2
Mean noise [Hz/cm ]
CDC 2015-2016: noise and dead time (1)
3.5
3
2.5
2
1.5
1
Layer 0
DIF 221
DIF 235
DIF 242
DIF 220
DIF 219
DIF 243
Layer 2
DIF 244
DIF 239
DIF 237
DIF 222
DIF 223
DIF 232
Layer 1
DIF 245
DIF 240
DIF 229
DIF 234
DIF 246
DIF 228
Layer 3
DIF 227
DIF 233
DIF 226
DIF 225
DIF 218
DIF 231
0.5
13/12/15
20/12/15
27/12/15
03/01/16
4
10/01/16
Mean dead time [%]
Mean noise [Hz/cm2]
0
3.5
3
2.5
2
17/01/16
24/01/16
Date [d/m/y]
20
18
16
14
12
10
8
1.5
6
1
4
0.5
0
2
12
February 26, 2016
13
14
15
16
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18
19
20
Mean temperature [°C]
0
Eve Le Ménédeu
12
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14
15
16
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20
Mean temperature [°C]
10/17
Performances
CDC 2015-2016: noise and dead time (2)
correlation factor with mean noise
DAQ is limited by the USB protocol used for reading the FE boards → important
dead time when the noise is increasing
1
0.5
0
−0.5
< Dead time >
<T>
−1
< P/T >
220
225
230
235
240
245
DIF
HV corrected for P/T:
HVeff = HV ×fcorr
with
fcorr =
P Tref
Pref T
(Pref = 1.013 hPa, Tref = 293.15 K)
→ still a correlation with temperature.
Ethernet FE board under development
February 26, 2016
Eve Le Ménédeu
11/17
Performances
Efficiency
Efficiency
Stability of efficiency over the TDF campaign in
2013
Efficiency in layer 0 during the CDC
campaign in 2015 - 2016
DIF 223
99
DIF 229
DIF 232
DIF 233
98
DIF 231
97
DIF 226
96
DIF 244
DIF 225
DIF 227
DIF 242
DIF 222
95
DIF 235
DIF 219
94
DIF 230
DIF 220
93
DIF 224
92
DIF 243
DIF 228
DIF 221
DIF 217
91
DIF 245
DIF 240
DIF 234
90
DIF 239
28/11 05/12 12/12 19/12 26/12 02/01 09/01 16/01
Date [d/m]
February 26, 2016
Eve Le Ménédeu
12/17
Performances
Rates stability
Commissionning:
changes in working
conditions
February 26, 2016
Eve Le Ménédeu
13/17
Data analysis
Final analysis
• Alignment of the detector (February
2016)
• Very preliminary results on the CDC
2015-2016 campaign
February 26, 2016
Eve Le Ménédeu
14/17
Data analysis
Flux through the Puy de Dôme
Flux integrated over β
data
rel. agreement = 100 × ( pred
− 1)
February 26, 2016
Ref: D. Chirkin, arxiv:hep-ph/0407078
Eve Le Ménédeu
15/17
R&D
R&D for building new chambers
• Goals
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Improving spatial and temporal resolution
by factor 10 → multi-gap GRPC
Reducing cost, electrical consumption and
complexity → readout by strips
• Glass and coated electrodes
characterization (serigraphy with
CEA-Saclay, AIDA 2020)
• New scheme for gas circulation and new gas
inlets/outlets
• Gas tightness
February 26, 2016
Eve Le Ménédeu
16/17
Conclusion
Conclusion
• RPC can be successfully used for muography :-)
• Sensible to atmospheric conditions → corrections
• Improvements foreseen to optimize (Multi-gap)GRPC to our application, low
consumption, portability, autonomy in energy, etc.
Thank you for your attention
February 26, 2016
Eve Le Ménédeu
17/17
Spares
References
• Inner structure of the Puy de Dôme volcano: cross-comparison of
geophysical models (ERT, gravimetry, muon immaging), A. Portal et al, Geosci.
Instrum. Method. Data Syst., 2, 47-54, 2013
• Towards a muon radiography of the Puy de Dôme, C. Cârloganu et al., Geosci.
Instrum. Method. Data Syst., 2, 55-60, 2013
• Joint measurement of the atmospheric muon flux through the Puy de Dôme
volcano with plastic scintillators and Resistive Plate Chambers detectors, F.
Ambrosino et al., J. Geophys. Res. Solid Earth, 120, doi:10.1002/2015JB011969,
2015 (MU-RAY and TOMUVOL collaborations)
February 26, 2016
Eve Le Ménédeu
18/17
Spares
Puy de Dôme thickness
TDF
CDC
February 26, 2016
Eve Le Ménédeu
19/17
Spares
Estimation of α and β
Ù
selection
Ù
selection
February 26, 2016
Eve Le Ménédeu
20/17