Gas Detectors: Theory and Application

The module “Gas detectors: theory and application” introduces the physics of particle gaseous detectors, its use in practical instruments and the applications in experimental apparatus. The following topics will be discussed during the lecture semester:

•       Units/Scales/Origin of Radiation/Brief History of particle detectors
•       Accelerators, Cross-section
•       Interaction of Particles with matter
•       Energy Loss + Fluctuations
•       Electrons/ions drift and diffusion
•       Signal Amplification (MWPC, MPGD)
•       Signal creation
•       Gas discharges
•       Position Measurement, Momentum Measurement, Particle identification
•       Drift Chambers, Time Projection chambers
•       Cerenkov, TRD, RPC Detectors

After successful completion of this module, the students are able to

• understand how particles interact with matter.
• derive Bethe-Bloch formula classically and be able to describe how specific energy loss depends on the properties of particles and matter they traverse.
• explain ionization, excitation, transition radiation, Cherenkov mechanisms.
• understand basic design criteria for particle detectors and recognize appropriate applications for different kinds of detectors.
• understand and exploit physics of gaseous detectors: ionization, drift and diffusion, amplification, signal creation.
• use the Ramo-Shockley theorem to predict currents induced on detector electrodes.
• discuss advantages and disadvantages of different gas mixtures.
• identify the limits of gaseous detectors: aging, rate dependency, discharge probability.
• recognize and discuss basic gaseous detector structures: wire chambers and micro-pattern-gaseous detectors.

No preconditions in addition to the requirements for the Master’s program in Physics.

The content of lectures is presented in the classroom during 2 x 45 min lectures per week. The power point based materials are available prior to the lecture in order to allow students for extra notes. The fundamental formulas (e.g. Bethe-Bloch formula, Ramo-Schockley theorem, etc.) are derived on a blackboard.

Each week another aspect of gaseous detectors is being discussed. The discussions are supported with examples of currently operational detectors and running experiments. For example, the LHC-Page1 is visited on the regular basis to discuss different aspects of the accelerator and large LHC (large hadron collider) experiments operation status.

Extra material is provided to students in form of scientific papers to be discussed in the following lectures. In the middle of the semester, a TUM lab visit is planned. During the visit, the basic features of the gaseous detectors (such as gain, energy resolution, ion backflow, etc.) is being presented in a hands-on session.

PowerPoint presentation, blackboard, discussions, post-lecture PDFs, lab visit, specialized articles in scientific journals, e.g. Nuclear Instruments and Methods A, Ann. Rev. Nucl. Part. Sci., Journal of Instrumentation

• W. R. Leo: Techniques for Nuclear and Particle Physics Experiments. Springer, (1994)
• W. Blum, W. Riegler, L. Rolandi: Particle Detection with Drift Chambers. Springer, (1993)
• F. Sauli: Gaseous radiation detectors. Fundamentals and applications, Cambridge, (2014)
  
  
• G. F. Knoll: Radiation Detection and Measurement. J. Wiley, New York (1979)
• N. Tsoulfanidis: Measurement and Detection of Radiation. Taylor & Francis, (1995)
• R. K. Bock, A. Vasilescu: The Particle Detector BriefBook. Springer, Berlin (1998)
• K. Kleinknecht: Detektoren für Teilchenstrahlung. Teubner, Stuttgart (1992)
• C. Grupen: Teilchendetektoren. Spektrum Verlag, (1993)

There will be an oral exam of 30 minutes duration. Therein the achievement of the competencies given in section learning outcome is tested exemplarily at least to the given cognition level using comprehension questions and sample problems.

For example an assignment in the exam might be:

• Discuss the Bethe-Bloch formula in different beta-gamma ranges.
• Discuss ion blocking techniques in Multi-Wire-Proportional-Chambers and Micro-Pattern-Gaseous-Detectors.
• Describe and compare signal formation in wire-based detectors (e.g. MWPCs) and MPGDs (e.g. GEMs).