Anmerkungen

Lieber Herr Giessgen,ich füge hier in ROT ein paar Anmerkungen undKorrekturen an.Ich rate, besser linksbündigen Textsatz zu verwenden, da er erheblich besserlesbar ist.

Proseminar: Understanding the Universe

Particle Detectors

Tom Gießgen

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outline

1. Introduction

2. Interaction with matter

3. Particle detectors in general

4. Semiconductor detector

5. Sources (besser: Literature)

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1. Introduction orWhy do we need particle detectors?

experiments in elementary particle physics:when particles are accelerated and collide,

detectors provide information about reaction_products-> conclusion about (! explanation of) actual process

for example at CERNvery (highly) complex (systems of) detectors: ALICE, ATLAS, CMS, ...

source: http://www.kennislink.nl http://www.kip.uni-heidelberg.de

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detecting cosmic radiation and neutrinos

Super-Kamiokande in Japan

http://www.hep.shef.ac.uk

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other applications:

CT, PET, MRT, X-Ray C-14 method

measurement of ionizing radiation(-> radioprotection)

PET

http://de.wikipedia.org

geiger müller counter

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searching for unkown chambers in the Chephren-pyramid

by measuring the intensity of muons

Sehr schönes Beispiel! Wichtig ist, dass Sie den Detektor und die Höhenstrahlung einzeichnen. Vielleicht auch ein Resultat?

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2. interaction with matter

charged particles interact mainly with electrons: stimulation (! Excitation) Ionization Coulomb scattering

other effects: Bremsstrahlung Coulomb scattering off the nucleus

uncharged particles interact with atomic matter (Photo effect, Compton effect) first and than create charged particles

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Energy-loss of particles is described by Bethe-Bloch formula:

~

z charge of the particleZ,A charge and mass number of detector matter

I value depending on matterbeta, gamma velocity and Lorentz_factor

C constant

−dEdx

Z z²Abeta²

ln I gamma² beta² −beta²−C

Achtung! Nicht lesbar!

Kleine Liste mit A:B:C:D:

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minimal ionization occurs when βγ ≈ 4

mean energy loss for MIP

absorber

H2

4.12O

21.82

Al 1.62Si 1.66Fe 1.48Pb 1.13

−dEdx

in MeVg / cm²

dE/dx * rhoin MeV / cmnoch hinzufügen

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3. Particle detectors in generalparticles: free molecules, atoms or elementary particles

there are detectors for measuring:

ionization and traceionization_chamber, Geiger-Müller Tube-

tube momentum

magnetic spectrometer time

scintillator (! scintillation) detector energy

semiconductor detector, calorimeter

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4. Semiconductor detectors

basically a (reverse biased) p-n-semiconductor diode

Si or Ge as semiconductor

http://ocw.weber.edu

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http://nsspi.tamu.edu

semiconductor detector with incoming particle

Gut erklären! Hier kommt es auf das bleibende Verständnis an.

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advantages: particles with high energy can be stopped less energy for creating electron-hole-pair required short time response simple installation

disadvantages: must be cooled (especially Germanium) small detector volume -> p-i-n semiconductor

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applications of semiconductor detectors

energy measurement

number of charge carriers is proportional to deposited energy

tracking particles

electrodes are stripes on the semiconductor-> 1-dim local information

http://wwwa1.kph.uni-mainz.de

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6. Sources (!Literature)

Teilchendetektoren, Claus Grupen, Wissenschaftsverlag 1993

The Particle Detector Briefbook, R. Bock, A. Vasilescu, Springer Verl. 1998

Physik, Paul Tipler, Akademischer Verlag 1994

wwwa1.kph.uni-mainz.de/Vorlesungen/WS08/FP-Seminar/handouts/KP06_Wanka.pdf