UNIVERSITÀ DEGLI STUDI DI MILANO

FACOLTÀ DI SCIENZE MATEMATICHE, FISICHE E NATURALI

Corso di Laurea triennale in Fisica

STUDY OF THE PERFORMANCES OF THE CDF SILICON DETECTORS AFTER TEN YEARS OF

OPERATIONS AND ESTIMATE OF THE RADIATION DAMAGE EFFECTS

Relatore: Prof.ssa Laura Perini ���

Relatore Esterno: Dott.ssa Sandra Leone

Correlatore: Dott. Ankush Mitra

Tesi di laurea di:

Luca SOMASCHINI

Matricola: 739626

Anno Accademico 2010 - 2011

!

!

pp

!s = 1.96TeV

pp

45KV

H2 H!

66ms 15Hz750KeV

H!

400MeV

805Hz

400MeV8GeV

5 · 101218.9ns

8GeV 150GeV

120GeV

150GeV

p p

120GeV8GeV

8GeV

105

3.3Km 8GeV

p

8GeV

150GeV

8GeV 150GeV

(1Km150GeV

980GeV!s =

1, 96TeV4K

Jc 1800A/mm 5T 4, 2K

36" 36

L =NBNpNpf

2"!#2p + #2

p

"

NB Np,p

#2p,p

#2p,p

´Ldt

N = #

ˆLdt

#

!341 · 1030 1

cm2s

"

(85 pb!1)

pp0.980TeV0.396µs0µrad57 cm

p : 39µm p : 31µm30min0.15TeV

p : 3010 p : 9.7 · 1010p : 82µA p : 27µA

6.12Kmp 25 · 1012/hr

p 2.4 · 1012

p = reBc

p r

4 "

(r, $,!)%

% = # $

2

% %&

E2 = p2 +m2 p $ m E % p

& =1

2

E + p $

E # p $& 1

2

p+ pcos$

p# pcos$= # $

2

25 50 75 100 125 150 175!

15

10

5

5

10

15

"

1, 4T

z0

d0

!0 d0

cot$

C

!

1, 2

1 < |%| < 23m

|%| < 11 < |%| < 2

x# y y # z

4m 2 cm1, 5Gev/c

K #"

%#!

2.5MHz150Hz

pp & bb 0, 1mb 100mb pp & qq

27KHz 900Hz

150Hz

$ = 3

%

r % 1, 6 |%| ' 4, 02, 1 ' r ' 17, 3 |%| ' 2, 0rcentral = 22 |%| ' 1, 0r = 20; 28 1, 0 ' |%| ' 2, 0

40 ' r ' 137 |%| ' 1, 0|%| ' 3, 6|%| ' 2, 0

store number1000 2000 3000 4000 5000 6000 7000 8000 90000

2000

4000

6000

8000

01/1101/1001/0901/0801/0701/0601/0501/0401/03

Delivered

Acquired

)-1

Luminosity (pb

week320 340 360 380 400 420

Effic

iency

(%

)

60

65

70

75

80

85

90

95

100

Time Range: from 1/2009 to 7/2011

Veff (r)Veff (r) = Veff

!r +R

"

E E

First Brillouin

zone

k k

!/a !/a 2!/a 3!/a -!/a-2!/a -!/a-3!/a

n=0

n=1

Veff = 0

-!/a !/a

E

-" -" +!

V = 0 V ! 0

V ! 0

k

+!

Veff (= 0

k = p!

R

E = k2!22m

Veff (r)

T = 0

[nv] ! 1# e! !

2kbT

T = 0

[nc] ! e! !

2kbT

!kb

! 5 10eV Al2O3 ! 5 eV SiO2 = 8, 00 eV NaCl = 8, 97 eVkbT " 0, 025 eV [nc] ! 10!35

Ge = 0, 75 eV Si =1, 17 eV

Nc =[nc]

V=

"

!c

g(') [n!]F d' = 2e"(µ!!c)

#mckBT

2"!2

$ 32

g(') [n!] µ( = 1

kBT T

mc = me 300K 0, 6 eV " µ " 1, 2 eV Nc % 2 · 1015m!3

Nc % 1028m!3

P As Si/Ge

T = 0

qe4!"o#

1r

! !Si Ge !

10!4 EHA

1010 cm!3

1017 cm!3 103 cm!3

Si Si Si

Si SiAs

Si Si Si

Si SiB

Ef

E

VB

CBe

Donor level

Ef

E

VB

CB

h

Acceptor level

!!0

µ

qe!!0 = µn # µp

) 1V

)*

*2* =)

'

) (x) =

%eND (#a < x ' 0)

#eNA (0 < x ' b)

bx

-eNA

0

eND

p(x)

-a

N

d*

dx=

%# eND

! (x+ a) (#a < x ' 0)eNA! (x# b) (0 < x ' b)

-a bx

E(x)

* (x) =

%# eND

2! (x+ a)2 + V (#a < x ' 0)eNA2! (x# b)2 (0 < x ' b)

-a bx

V

V(x)

x = 0

(a+ b) b =2'V

eNA.

d = b $ a

d )=&

2'V

eN

C ='

d)=

&'eN

2V

SiO2

3, 6 eV ) 30 eV

2, 33 g/cm!3 )3, 8MeV /cm

N-bulk

n+ n+ n+p+ p+

N-bulk

n+ n+ n+

Si SiO2

AlSiO2

+

–

h+ e-+

–

h+ e-

xi !xi# !

2 ' x ' xi+!2

x =1

!

xmaxˆxmin

xdx = xi

#2x =

ˆ xmax

xmin

f(x)(x# x)2dx =1

!

+!2ˆ

!!2

x2dx =!2

12

n-Sin-Si

SiO2

800# 1200

UV light

Photo- resistmask

B

As

p+p+

n+

600

Al

fb!1

1, 25 cm < r < 2, 1 cm" 15W

" 12W

14.7 cmr # ! x# y

6+6

r = 1, 35 cm r = 1, 62 cm

47 cm 50µm 1#1, 5µm5µm 10#12µm 50µm

100µm

x#y !

X [cm]-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

f800

f803_0

f810

f813_0

f820

f823_0

f830

f833_0

f840

f843_0

f850

f853_0

Barrel 0, Segment 0

X [cm]-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

f801

f803_2

f811

f813_2

f821

f823_2

f831

f833_2

f841

f843_2

f851

f853_2

Barrel 0, Segment 1

X [cm]-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

f802

f803_1

f812

f813_1

f822

f823_1

f832

f833_1

f842

f843_1

f852

f853_1

Barrel 0, Segment 2

X [cm]-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

fa00

fa03_0

fa10

fa13_0

fa20

fa23_0

fa30

fa33_0

fa40

fa43_0

fa50

fa53_0

Barrel 1, Segment 0

X [cm]-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

fa01

fa03_2

fa11

fa13_2

fa21

fa23_2

fa31

fa33_2

fa41

fa43_2

fa51

fa53_2

Barrel 1, Segment 1

X [cm]-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

fa02

fa03_1

fa12

fa13_1

fa22

fa23_1

fa32

fa33_1

fa42

fa43_1

fa52

fa53_1

Barrel 1, Segment 2

Z [cm]-40 -30 -20 -10 0 10 20 30 40

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

f800 f801 f802

f803_0 f803_1f803_2

f810 f811 f812

f813_0 f813_1f813_2

f840 f841 f842

f850 f851 f852

f853_0 f853_1f853_2

fa00 fa01 fa02

fa03_0 fa03_1fa03_2

fa10 fa11 fa12

fa13_0 fa13_1fa13_2

fa20 fa21 fa22

fa50 fa51 fa52

fa53_0 fa53_1fa53_2

Positive X

Z [cm]-40 -30 -20 -10 0 10 20 30 40

Y [

cm

]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2f810 f811 f812

f820 f821 f822

f823_0 f823_1f823_2

f830 f831 f832

f833_0 f833_1f833_2

f840 f841 f842

f843_0 f843_1f843_2

fa20 fa21 fa22

fa23_0 fa23_1fa23_2

fa30 fa31 fa32

fa33_0 fa33_1fa33_2

fa40 fa41 fa42

fa43_0 fa43_1fa43_2

fa50 fa51 fa52

Negative X

X Position (cm)-1.5 -1 -0.5 0 0.5 1 1.5

Y P

ositio

n (

cm

)

-1.5

-1

-0.5

0

0.5

1

1.5

2

Ladder PositionLadder Position

"/6 x # y

25 (50) µm

700 # 1000V )350V

X Distance (cm)0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

0

2

4

6

8

10

12

X DistanceXDistance

Entries 44Mean 0.1288RMS 0.02401

X Distance

Y Distance (cm)0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

0

2

4

6

8

10

Y DistanceYDistance

Entries 44Mean 0.1154RMS 0.02194

Y Distance

Radial Distance (cm)0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24

0

2

4

6

8

10

12

14

R DistanceRDistance

Entries 44Mean 0.1743RMS 0.0242

R Distance

500V

300µm< 80µm

78, 400mm14, 830mm76, 401mm12, 831mm

50µm25µm8µm

7# 8µm> 10 pf/cm< 1, 2 pf/cm

> 600V2max

300µm< 50µm

78, 400mm8, 430mm76, 401mm6, 431mm50µm25µm8µm

7# 8µm> 100 pf/cm< 1, 2 pf/cm

> 600V1max

!

) 1016

SiO2 ) 17 eV /pair

Silicon bulk

SiO2 + +

+ +

+

+

+ +

+

+

+

- - - - - - - - -

+V

Charge (in this case negative) trapped at oxide-Si interface

metal! polysilicon

Charge trapped in oxide

1MeV60 # 70KeV ) 1000

Interstitial and vacancy defect creation.

exiting particle

incident particle

interstitial vacancy

Frenkel pair

V

Before type inversion:

depletion

depletion

V

After type inversion:

n+

n+

p+

p+

3 fb!1

12 fb!1

30 000 100 000

pt * %

!! 300µm

q% %

nhits

q#

' =ntracks

ntracks

ntracks ntracks

" (= 0 " = 0

q#

Qmax

1 + e!!x!

+ 65V

!+ Qmax

95

+

Bias voltage (V)0 20 40 60 80 100 120 140 160 180 200

Clu

ste

r C

ha

rge

(A

DC

co

un

ts)

0

5

10

15

20

25

30

35

40

eff

icie

nc

y

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1Fit Parameters

0.541± p0 = 17.046

0.004± p1 = 0.073

0.940± p2 = 50.190

2.073± p3 = 83.468

Extremal Charges

0.19±Charge Max = 27.90

0.20±Charge Min = 12.12

Ladder: fa23_2

+95

1.62 cm

1.62 cm

#2

NDF ,2

1, 8. #2

NDF

,2 3

+

,2

,2 = 3

,2

Luminosity (pb-1)0 2000 4000 6000 8000 10000 12000

De

p V

olta

ge

(V

)

50

100

150

200

250

f843_0 / ndf 2! 17 / 25

Prob 0.8817p0 3.425± 26.86

p1 0.0006835± 0.01816

/ ndf 2! 17 / 25

Prob 0.8817p0 3.425± 26.86

p1 0.0006835± 0.01816

f843_0

,2

Luminosity (pb-1)0 2000 4000 6000 8000 10000 12000

De

p V

olta

ge

(V

)

50

100

150

200

250

f852 / ndf 2! 54.51 / 24

Prob 0.0003641p0 2.137± 18.1

p1 0.0006265± 0.01742

/ ndf 2! 54.51 / 24

Prob 0.0003641p0 2.137± 18.1

p1 0.0006265± 0.01742

f852

,2

Luminosity (pb-1)0 2000 4000 6000 8000 10000 12000

De

p V

olta

ge

(V

)

50

100

150

200

250

300

f823_1 / ndf 2! 135.7 / 19

Prob 1.229e-19p0 4.893± 41.39 p1 0.0008957± 0.0181

/ ndf 2! 135.7 / 19

Prob 1.229e-19p0 4.893± 41.39 p1 0.0008957± 0.0181

f823_1

,2

Luminosity (pb-1)0 2000 4000 6000 8000 10000 12000

De

p V

olta

ge

(V

)

0

100

200

300

400

500

600

700

800

900

fa00 / ndf 2! 720.3 / 21

Prob 0p0 5.572± -75.59 p1 0.001745± 0.05489

/ ndf 2! 720.3 / 21

Prob 0p0 5.572± -75.59 p1 0.001745± 0.05489

fa00

ChiSquareEntries 72

Mean 3.052

RMS 1.83

0 2 4 6 8 100

5

10

15

20

25

ChiSquareEntries 72

Mean 3.052

RMS 1.83

Chi Square Histogram

Chi Square per degree of freedom

,2

) 50V ) 100V

Luminosity (pb-1)0 2000 4000 6000 8000 10000

De

p V

olta

ge

(V

)

50

100

150

200

250

All Together

1/r r

D

D =A

'(x# x0)

2 + (y # y0)2(!

2L

A +(x0, y0)

A +D = D (r, r0, z, L)

r0 r

0

500

1000

1500

2000

2500

Am

p (

Gy)

0

0.5

1

1.5

2

2.5

-200 -150 -100 -50 0 50 100 150 200

z (cm)

!

+ A z

Integrated Luminosity (fb-1)0 1 2 3 4 5 6 7 8

De

ple

tio

n V

olt

ag

e (

V)

0

20

40

60

80

100

120

140

160

180

200

Barrel (0-5) Layer 0

Phi Side Barrel 0Phi Side Barrel 1Phi Side Barrel 2Phi Side Barrel 3Phi Side Barrel 4Phi Side Barrel 5

Barrel (0-5) Layer 0

r = 35 cm r = 17 cm

2.54 cm

94 cmA +

+ = 1.5 A = 1500

1.35 cm

1.62 cm

Dose (Krad)0 1000 2000 3000 4000 5000 6000 7000 8000

De

p V

olta

ge

(V

)

50

100

150

200

250

All Together

Dose (Krad)0 1000 2000 3000 4000 5000 6000 7000 8000

De

p V

olta

ge

(V

)

50

100

150

200

250

WIDEs

Dose (Krad)0 2000 4000 6000 8000 10000

De

p V

olta

ge

(V

)

50

100

150

200

250

300

350

400

450

500

NARROWs

x# y

2V

7.5 · 10!5 cm9.4 · 10!5 cm

10µm

Store Number0 2000 4000 6000 8000

X B

ea

m P

osi

tion

-0.4

-0.35

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

0

X Beam Position

Store Number0 2000 4000 6000 8000

Y B

ea

m P

ositio

n

0

0.1

0.2

0.3

0.4

0.5

0.6

Y Beam Position

Store Number0 2000 4000 6000 8000

Z B

ea

m P

osi

tion

-20

-15

-10

-5

0

5

10

15

Z Beam Position

5, 3 · 10!3 cm 0, 34 cm

94 cm

$ 0, 001milli # rad

Store Number0 2000 4000 6000 8000

X B

ea

m P

osi

tion

-0.4

-0.35

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

X Beam Position

Store Number0 2000 4000 6000 8000

Y B

ea

m P

ositio

n

0

0.1

0.2

0.3

0.4

0.5

0.6

Y Beam Position

Store Number0 2000 4000 6000 8000

Z B

ea

m P

osi

tion

-15

-10

-5

0

5

10

15

Z Beam Position

X Beam Position (cm)-0.4 -0.35 -0.3 -0.25 -0.2 -0.15 -0.1 -0.05

Y B

ea

m P

ositio

n (

cm

)

0

0.1

0.2

0.3

0.4

0.5

0.6

XY Beam Position

l = 94 cmR ) 1µm

R = l · tan ($)

Store0 1000 2000 3000 4000 5000 6000 7000 8000 9000

)-1

Lu

min

osi

ty

(nb

0

2000

4000

6000

8000

10000

12000

Luminosity Per Store

R

l = 94 cm

x y# 40µm

Store Number0 2000 4000 6000 8000

X B

ea

m S

lop

e (

mili

-ra

d)

0.0002

0.0003

0.0004

0.0005

0.0006

0.0007

0.0008

0.0009

0.001

X Beam SlopeX Beam Slope

Store Number0 2000 4000 6000 8000

Y B

ea

m S

lop

e (

mili

-ra

d)

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

-310!

Y Beam SlopeY Beam Slope

Store Number0 1000 2000 3000 4000 5000

X B

ea

m W

itdh

(cm

)

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

X Beam WidthX Beam Width

Store Number0 1000 2000 3000 4000 5000

Y B

ea

m P

ositi

on

(cm

)

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

Y Beam WidthY Beam Width

V (L) V (NR)

rB (NR) rB (NS)NR NS,

L (NS)NS

V rB LV

E!

ecti

ve

dis

tan

ce

!4

D

Di = Di!1 +A

r$i(Li # Li!1)

0.0042 0.0033

Dose (Krad)0 2000 4000 6000 8000 10000

De

p V

olta

ge

(V

)

50

100

150

200

250

f843_0

Dose (Krad)0 1000 2000 3000 4000 5000 6000 7000 8000

De

p V

olta

ge

(V

)

50

100

150

200

250

f852

Dose (Krad)0 2000 4000 6000 8000 10000

De

p V

olta

ge

(V

)

50

100

150

200

250

fa33_1

Dose (Krad)0 2000 4000 6000 8000 10000

De

p V

olta

ge

(V

)

50

100

150

200

250

fa31

Dose (Krad)0 1000 2000 3000 4000 5000 6000 7000 8000

De

p V

olta

ge

(V

)

40

60

80

100

120

140

160

180

200

220

All Together

Dose (Krad)0 1000 2000 3000 4000 5000 6000 7000 8000

De

p V

olta

ge

(V

)

40

60

80

100

120

140

160

180

200

220

All Together

Dose (Krad)0 500 1000 1500 2000 2500 3000 3500

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

180

All Together - Close Up

Dose (Krad)0 500 1000 1500 2000 2500 3000 3500

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

180

All Together - Close Up

0.005 0.01 0.015 0.02 0.025 0.03 0.0350

2

4

6

8

10

12

14

Slope Distribution - Before and After Correction

Dose (Krad)0 2000 4000 6000 8000 10000 12000

De

p V

olta

ge

(V

)

0

50

100

150

200

250

300

SGS Thompson- Hamamatsu - MicronSGS Thompson- Hamamatsu - Micron

!

!

!!

!

!

2 # 5 cm

()!-150 -100 -50 0 50 100 150

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

Per Wedge GroupingPer Wedge Grouping

!

/ ndf 2! 197 / 11p0 0.9± 141.4

)° ("-150 -100 -50 0 50 100 150

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

180

/ ndf 2! 197 / 11p0 0.9± 141.4

/ ndf 2! 197 / 11p0 0.9± 141.4

Per Wedge Gruping

/ ndf 2! 49.41 / 11p0 0.9± 143.4

()"-150 -100 -50 0 50 100 150

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

/ ndf 2! 49.41 / 11p0 0.9± 143.4

/ ndf 2! 49.41 / 11p0 0.9± 143.4

Per Wedge Grouping

!

/ ndf 2! 135.3 / 11p0 1.4± 194.7

)° ("-150 -100 -50 0 50 100 150

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

180

200

220

240

/ ndf 2! 135.3 / 11p0 1.4± 194.7

/ ndf 2! 135.3 / 11p0 1.4± 194.7

Per Wedge Gruping

/ ndf 2! 50.22 / 11p0 1.4± 202.9

()"-150 -100 -50 0 50 100 150

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

180

200

220

/ ndf 2! 50.22 / 11p0 1.4± 202.9

/ ndf 2! 50.22 / 11p0 1.4± 202.9

Per Wedge Grouping

!

Z (cm)-50 -40 -30 -20 -10 0 10 20 30 40 50

De

p V

olta

ge

(V

)

0

20

40

60

80

100

120

140

160

Per Barrel Grouping - AllPer Barrel Grouping - All

Store Number1000 2000 3000 4000 5000 6000 7000 8000 9000

Z B

ea

m P

osi

tion

(cm

)

-15

-10

-5

0

5

10

15

Z Beam Position

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http://agenda.infn.it/conferenceTimeTable.py?confId=3245