English for young physicists WS 09/10 Niklas Müller The PANDA Calorimeter English for young physicists WS 09/10 Niklas Müller

Structure Motivation Physical Background FAIR at GSI Darmstadt The PANDA Detector Process of Scintillation Conclusion / Outlook

Motivation 1.1 General What is the structure of matter and how has everything evolute? Particle physics are researching the subatomic constituents of matter in the Universe and the fundamental forces binding them.

1. Motivation 1.2 PANDA and FAIR How did matter in the early Universe develop ? Where do the atomic elements come from? How does the electromagnetic force work? Where does the strong interaction, which binds the particles of atomic nuclei come from?

Physical background 3.1 subatomic particles Every matter is made of atomic nuclei, which consist of positiv charged protons (+p) and neutral charged neutrons (n) But why do they stick together? There are a lot of subatomic, fundamental particles  Quarks Quarks are bound together by the so called strong interaction

3. Physical background 3.2 Quarks and the standard model Force Carriers Elementary particles Elementary Particles Quarks Bosons Leptons Composite Particles

3. Physical background 3.3 Strong Interaction The strong Interaction is one of the four fundamental forces: - Gravity - Elektromagnetism - Weak - Strong Gluons (g) are the carriers for the strong interaction between quarks They mediate a color charge between quarks Example Proton: Blue up-quark Red up-quark Green down-quark Gluons Have also a color charge and mediate quark-color

3. Facility for Antiproton and Ion Research FAIR is an international scientific project at the GSI in Darmstadt for accelerating and colliding particles and ions - accelerator rings are 1100m in circumference SIS 18 UNILAC SIS 100/300 antiproton beam with energies up to 4 GeV HESR 2500 scientists from 44 countries PANDA Collision of Protons and Antiprotons RESR

3. Facility for Antiproton and Ion Research

The PANDA Detector 4.1 Overview Anti-Proton ANhilation at DArmstadt Fixed Target Experiments: - A beam of Anti-protons collides with a hydrogen target inside the detector - A variety of composite particals is produced and detected in every spatial direction - Several Layers of different detectors surround the target - Because of Conservation of momentum most of the particles are detected behind the collision area Detection of e+ e-, + -, + -, , K+ K- , p+ and 

4. The PANDA Detector 4.1 Components Target Spectrometer Forward Spectrometer Beam of anti- protons Target = frozen Hydrogen pellet p+

4. The PANDA Detector 4.2 Target Spectrometer Micro Vertex Detector  Where is the particle? Central Tracker  What momentum has the particle? DIRC  What speed has the particle Electromagnetic Calorimeter  What energy has the particle? Superconducting Solenoid Moun Detectors

4. The PANDA Detector 4.3 The Electromagnetic Calorimeter - Detects the energy of particles About 16.000 Scintillation-Detectors of PbWO4 - Geometric coverage 96% 4π - Operating temperature -25°C Events rate about

5. Process of Scintillation 5.1 Physics - Scintillators are materials that absorbe the energy of a particle - Photons and e- that hits the crystal produce a electron-photon shower Conversion Compton Scattering Photo-effect Energy - Other particles do ionisation

5. Process of Scintillation 5.2 Detectors Detected light is proportional to the deposited energy Light signal produces an electric Current within the LAAPD Signal is digitalized and processed by the readout-electronics counts counts counts Research of the properties and quality parameters of PbWO4 is done in Giessen channel no channel no channel no

6. Conclusion / Outlook PANDA will help to make a better understanding of the fundamental questions of mankind by researching the origin of mass, force and energy. PANDA is also an option to write your Bachelor Thesis here at Giessen University.

Sources FAIR PANDA - EMC Technical Design Report FAIR PANDA - Solenoid and Dipole Spectrometer Magnets TDR FAIR PANDA - Physics Performance Report Messmethoden der Kern und Teilchen Physik – Vorlesung Teil 5c Kalorimetrie – Rainer Novotny - http://www-panda.gsi.de/ - http://www.gsi.de/fair/ - http://www.wikipedia.org/