a comparative study of mixed irradiated silicon strip sensors
DESCRIPTION
A comparative study of mixed irradiated silicon strip sensors 19 th RD50 Workshop 21.11 . – 23.11.2011. Florian Petry , Robert Eber T. Barvich , F. Bögelspacher , W. de Boer, A. Dierlamm , A. Kornmayer , Th. Müller, P. Steck. Ingredients for the study. Introduction Sensors - PowerPoint PPT PresentationTRANSCRIPT
KIT – University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association
Institut für Experimentelle Kernphysik
www.kit.edu
A comparative study of mixed irradiated silicon strip sensors19th RD50 Workshop 21.11. – 23.11.2011
Florian Petry, Robert EberT. Barvich, F. Bögelspacher, W. de Boer, A. Dierlamm, A. Kornmayer, Th. Müller, P. Steck
19th RD50 Workshop221.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Ingredients for the study
Introduction
Sensors
Mixed irradiation scheme
Annealing procedure
ALiBaVa measuremets
Results
Charge collection
Signal to noise ratio
Leakage current
Summary
19th RD50 Workshop321.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Sensor overview
Sensor thickness: 300µm
5 sensors of each material
Material Type Pitch (µm) Manufacturer
FZ p-in-n 50 (5) HIP
FZ n-in-p (p-spray) 80 (5) Micron
MCz p-in-n 50 (5) HIP
MCz n-in-p (p-spray) 50(1), 80(3), 100(1) Micron
19th RD50 Workshop421.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Irradiation
Mixed irradiation with protons and neutrons
Chose 5 fluence mixtures corresponding to 5 different radii in the CMS Tracker after 3000fb-1
Irradiation with Protons in Karlsuhe
ZAG: Cyclotron, 23MeV protons
Irradiation with neutrons in Louvain-la-Neuve
Neutron generation by shooting deuterons on Be target
1 step only neutron irradiation
Radius (cm)
Total fluence (neq/cm2)
Neutron(neq/cm2)
Proton(neq/cm2)
5 1.2*1016 10.0*1014 110*1014
20 1.8*1015 5.5*1014 12.5*1014
60 7.3*1014 4.5*1014 2.8*1014
120 4.6*1014 3.8*1014 0.8*1014
>120 4.0*1014 4.0*1014 -
19th RD50 Workshop521.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Annealing
Logarithmic annealing steps to observe
short term (beneficial) annealing
long term (reverse) annealing
Temperature (°C)
Duration (min)
Sum @RT Annealing (d)
60 20 4
60 20 8
60 40 15
60 76 28
80 15 58
80 30 133
80 60 337
M.Moll, phd thesis, Hamburg, 1999
19th RD50 Workshop621.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Parameterisation of charge collection
Beneficial annealing Reverse annealing Stable damage
19th RD50 Workshop721.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Measurement
Measurement Setup: 2 ALiBaVa stations in Karlsruhe90Sr source
Signal
Signal to noise ratio
Leakage current
Temperature: -20°C (-30°C)
Voltage 0V – 1000V
Cuts
Seed: S/N > 5
Neighbour: S/N > 2
Total error on measurements: 2.5%
Error on irradiated fluence > 10%
The small ALiBaVa station
HVPre-cooling
DB
Scintillator
Sensor
19th RD50 Workshop821.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Measurement Results
Parameters
T = -20°CV = 900V
19th RD50 Workshop921.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Charge collection
P-type materials collect more charge than n-type materials
FZ-n
shows highest dependence on annealing time
Large drop in charge collection after 10d@RT (reverse annealing)
Only small dependence of charge collection on annealing time for other materials
P
N
P
N
Incr
easi
ng f
luen
ce
19th RD50 Workshop1021.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Charge collection
1.8*1015neq/cm2
FZ-p shows largest charge collection
Charge multiplication for large annealing (charge > 24000 e-)
MCz: almost no dependence on annealing time
1.2*1016neq/cm2
FZ-n: No signal at highest fluence for all annealing steps
FZ-p: rise in signal for long annealing time
MCz-p sensor didn‘t work for first annealing step
MCz-n: no signal at T= -20°C
Incr
easi
ng f
luen
ce
MCz-nT= -30°C
19th RD50 Workshop1121.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Charge Collection overview
Max: 24k
Max: 22k
Max: 15k/40k
Max: 10k
MCz-nT=-30°C
No Signal at T=-20°C
19th RD50 Workshop1221.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Signal to Noise
P
N
4. Lower limit, seed cut > 52. Same rangeFZ-n drops out
1. All quite good 3. p is better than n
19th RD50 Workshop1321.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Charge multiplication
Signal increases after Annealing of >100d@RT
Signal to noise ratio doesn‘t decrease
Large increase of leakage current
19th RD50 Workshop1421.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Charge collection / multiplication
Landau-Gauß-Fit broadens very much
Peak is shifted to higher values
Not a MIP signal any more
usual distribution
19th RD50 Workshop1521.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Charge collection / multiplication
MPV cannot be determined very well
MCz-nT=-30°C
FZ-p + MCz-pT=-20°C
19th RD50 Workshop1621.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Charge Collection / Signal to Noise Summary
CC
S/N
T= -30°CMCz-n
Charge multiplication
15d 337d
19th RD50 Workshop1721.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Leakage Current Summary
Charge multiplication
15d 337d
19th RD50 Workshop1821.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Neutron only / mixed irradiation
Mixed irradiation F = 4.6*1014neq/cm2
F(p) = 0.8*1014neq/cm2
F(n) = 3.8*1014neq/cm2
Neutron only irradiation
F(n) = 4.0*1014neq/cm2
1. Neutron only irradiation: • FZ-n has smaller signal than
MCz-nsimulated by M. Huhtinen NIMA 491, 194-215, 2002
2. Mixed irradiation:• No improvement in CC due to
mixed irradiationG. Casse et al. Vertex2008:036, 2008
MCz
FZ
N-type
19th RD50 Workshop1921.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Summary
P-type materials showed higher charge collection and signal to noise
FZ-p performance most interesting
Charge multiplication only seen with FZ-p F > 1*1015neq/cm2, A > 100d@RTManufacturer Micron
Highest leakage current
FZ-n showed largest dependence on annealing time
Not usable at high fluences
Charge collection of MCz materials does not anneal very much
MCz-n is not working at T= -20°C at F=1.2*1016neq/cm2
Additional differences between n-type and p-type materials due to manufacturer?
Compare to other studies: Charge multiplication study, HPK
19th RD50 Workshop2021.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Thanks for your attention
Diploma thesis of F. Petry (IEKP-KA/2011-27)
Will be published soon:
http://www-ekp.physik.uni-karlsruhe.de/pub/web/thesis/iekp-ka2011-27.pdf
19th RD50 Workshop2121.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
BACKUP
19th RD50 Workshop2221.-23.11.2011
Robert EberInstitut für Experimentelle Kernphysik, KIT
Prof. Max Mustermann - Title