![Page 1: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/1.jpg)
Silicon Detectors and DAQ Silicon Detectors and DAQ principles for a physics principles for a physics
experimentexperiment
![Page 2: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/2.jpg)
![Page 3: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/3.jpg)
Telescopes
![Page 4: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/4.jpg)
Human eyes
![Page 5: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/5.jpg)
Microscope
![Page 6: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/6.jpg)
Accelerators
![Page 7: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/7.jpg)
Detectors
![Page 8: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/8.jpg)
But where does it all start from?
![Page 9: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/9.jpg)
Electronic properties of materials
Atoms are made of proton, neutrons (nucleus) and electrons
Valence and conduction electrons are responsible for the principal characteristics of different atoms
![Page 10: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/10.jpg)
Electronic properties of materials
Everyone wants to be noble !!!
Water is a good example….
![Page 11: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/11.jpg)
Electronic properties of materials
Atomic levels Molecular bands
![Page 12: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/12.jpg)
If some electron is promoted in the conduction band, what may occur?
1) Drift: an external field can move these electrons
2) Multiplication; if the field is strong enough
3) Recombination: if nothing happens, electrons fall back to valence band
What happens then?
How can we describe the situation?
![Page 13: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/13.jpg)
Physicians must be smart and clever….
holes !!!
h+
h+
h+
h+
![Page 14: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/14.jpg)
....and do a smart use of drugs!!!
n doping p dopingWhy ?
![Page 15: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/15.jpg)
p-n Junctions
Fermi level definition
Electrons and holes diffusion
Non equilibrium situation
Donors and acceptors ions field plays against diffusion and equilibrium is reached
Equilibrium !!! … ?
![Page 16: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/16.jpg)
p-n Junctions
Equilibrium is reached when the two Fermi levels are at the same energy
A sort of slope is then created, hard to climb up and easy to roll down!
Equilibrium does not mean immobility!!!
![Page 17: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/17.jpg)
p-n Junctions
Breakdown voltageVbr
Junctions are the basic devices for all semiconductor detectors!
V=RxI
![Page 18: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/18.jpg)
Particles through matter
How can we detect them?
![Page 19: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/19.jpg)
Particles’ measurements
A particle passes through a silicon thickness, generating e-h pairs
e- and h+ are collected by anode and cathode (be aware of recombination…)
An electric field causes electron flow through the device and created charge can be collected (by capacitor for ex.)
![Page 20: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/20.jpg)
SDD, a clever anti-recombination device
An electric field leads electrons, generated by particle flow (x-Rays or ionizing) to a small collector anode. At the same time holes are immediately removed from electron’s path by cathode strips.
![Page 21: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/21.jpg)
Position measurements: strips !
![Page 22: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/22.jpg)
We got the charge...
and now what?
![Page 23: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/23.jpg)
Analog – Digital conversion
Digital signal; signal is a function of discrete numbers, F(N)
Analog signal; signal is a function of continuous numbers, usually time, F(t)
The world is analogic but Pc and analysis software can only work with digital informations…..
Analog signal have to be converted to digital signals!
![Page 24: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/24.jpg)
Analog – Digital conversion
Sampling Quantization
![Page 25: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/25.jpg)
Analog – Digital conversion
channels
![Page 26: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/26.jpg)
Analog – Digital conversion
In this world…..
….this is poker !!!
![Page 27: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/27.jpg)
Analog – Digital conversion
Converting analog signals into digital signals, some information may be lost … but are they really necessary?
![Page 28: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/28.jpg)
From analog signals to files and histograms:
Data AQuisition methods
![Page 29: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/29.jpg)
DAQ
What are we interested in ? Which information can we get?
Charge Timing Rates
![Page 30: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/30.jpg)
DAQ : Discriminators
![Page 31: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/31.jpg)
DAQ : QDC (charge to digital converter)
QDC values(integer numbers)
Histograms
![Page 32: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/32.jpg)
DAQ : TDC (time to digital converter)
![Page 33: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/33.jpg)
DAQ : Scaler
4 events in 10 seconds Rate = 0,4 Hz
![Page 34: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/34.jpg)
A real example!
![Page 35: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/35.jpg)
MPPC (Multi Pixel Photon Counters) detectors
Each pixel acts like a p-n junction
Breakdown current is used
Output signals are summed
![Page 36: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/36.jpg)
MPPC (Multi Pixel Photon Counters) detectors
![Page 37: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/37.jpg)
MPPCSignal coming out from the detecor is then:
QDC spectrum is then composed by several pixes with fixed distance
![Page 38: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/38.jpg)
New physicists?
Questions?
![Page 39: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/39.jpg)
An experience in the lab:
e- charge estimation
![Page 40: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/40.jpg)
areadtiQ
t
Qi
iRV
t
t
tot
1
0
Ohm law
Current definition
Charge definition
![Page 41: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/41.jpg)
b (time)
h (Volt Ω)
2
hbQ
![Page 42: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/42.jpg)
C
sV
R
tVQ
nst
mVV
tot12
92
1051052
1025102
2
)525(
)520(
CAA
AAQQ
preamp
tote
preampetot
195
12
det
det
103,1105105,7
105
![Page 43: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/43.jpg)
Is the result ok?errors…..
st
VV
tR
VV
R
tQ
9
3
22
22
105
105
22
CQ
CQ
e
19
12
103,1
106,1
Huge errors due to the big error estimation on measured values of t and V
![Page 44: Silicon Detectors and DAQ principles for a physics experiment](https://reader030.vdocuments.us/reader030/viewer/2022032606/56812d92550346895d92ad8c/html5/thumbnails/44.jpg)
Can you do it better ???