87976 - Laboratory of Nuclear and Subnuclear Physics 2

Academic Year 2022/2023

  • Moduli: Luigi Guiducci (Modulo 1) Marco Selvi (Modulo 2) Federica Primavera (Modulo 3)
  • Teaching Mode: Traditional lectures (Modulo 1) Traditional lectures (Modulo 2) Traditional lectures (Modulo 3)
  • Campus: Bologna
  • Corso: Second cycle degree programme (LM) in Physics (cod. 9245)

Learning outcomes

At the end of the course the student will have a good knowledge of the detectors concepts to study events produced with colliders or fixed target experiments and will be familiar with the main techniques to identify particle charge and mass. Moreover, practice in the laboratory will allow the student to become familiar with some basic detectors, electronic instrumentation, DAQ system, data analysis and writing a report on the experimental work performed in the laboratory sessions.

Course contents


Cherenkov detectors

Cherenkov radiation: mechanism and features. Threshold effect and Cherenkov threshold counters. Radiator choice. Differential counters. Ring Imaging Cherenkov counters (RICH).Focusing techniques. Examples of application of Cherenkov detectors to several present and past experiments (Alice, Delphi, Babar, LHCb). Air Cherenkov detectors examples.

 

Transition Radiation Detectors

- Production of Transition Radiation. Spectrum, other features and consequences. Dependence of TR emission and detection on particle gamma, radiator features, detector features. Usefulness of TR for PID. Selected TR detector examples: AMS-02, Alice, Atlas.


Calorimeters

- Introduction. Main classification of calorimeters; principles of energy measurement; requirements.

- Electromagnetic showers. Recap of electron and photon energy loss in matter. Electromagnetic (EM) showers development and features: radiation length and Moliere radius. Longitudinal and transverse development of EM showers. Direction of shower particles and consequences.

- Electromagnetic calorimeters. Parametrization of calorimeter resolution. Homogeneous EM calorimeters: materials and implementation examples. Sampling EM calorimeters: features, technologies, implementation examples. Preshower detectors.

- Hadronic showers: generalities, nuclear interaction length, longitudinal and transverse development. EM component: physics mechanism, energy estimate and parametrisation. Content of the non-em component and consequences. Lateral and longitudinal profiles of hadronic showers. Hadronic shower profile in Cherenkov calorimeters. Shower containment.

- Calorimeter response: definition and meaning. Response in homogeneous calorimeters: electrons, muons, hadrons. e/h vs e/pi. Compensation. Measuring e/h indirectly. Sampling calorimeters: definition of sampling fraction in terms of mip energy loss. Response of a sampling calorimeter to electrons and photons. Spatial dependence of em response. Response to hadrons: low energy vs high energy. Response to individual non-em components. Response to neutrons. Neutron sampling fraction in hydrogen-enriched materials. History of compensation attempts. Summary of calorimeter compensation techniques.

- Fluctuations in calorimetry: impact on energy resolution. Sampling fluctuations and stochastic term of resolution. Fluctuations in hadronic showers, invisible energy fluctuations, impact on compensating vs non-compensating calorimeters. Electronics noise and other instrumental effects. Sampling fraction fluctuations. Summary and consequences for calorimeter design.

- Calorimeter calibration. Definitions and tools. Example for homogeneous calorimeters. Calibrating longitudinally segmented calorimeters: issues of section intercalibration with showers. Other effects.

- Future calorimeter projects. Motivations, future accelerator and detector projects. High granularity calorimeters: CALICE developments and the CMS HGCAL for HL-LHC. Dual readout calorimeters: theory, DREAM and RD52 developments, the dual readout calorimeter for the IDEA detector proposal for FCC.

 

Detectors for very weakly interacting particles (neutrinos and dark matter candidates)

- Super Kamiokande. ANTARES. KM3. XENON. DARKSIDE.

 

Laboratory

The baseline goal of the laboratory work is the measurement of the muon lifetime. The activity includes setting up the apparatus, data acquisition and analysis. A written report about the measurement will be required. In-class introductory lectures will prepare the students to the laboratory activity, which will be supervised by the professor and tutors and will work in small groups (3 students per group).

Readings/Bibliography

Material will be available on virtuale.unibo.it.

The textbooks dealing with the material of the course are

- W.R. Leo, Techniques for Nuclear and Particle Physics Experiments, Springer

- K. Kleinknecht, Detectors for Particle Radiation, Cambridge UP

- G.F. Knoll, Radiation Detection and Measurement, J. Wiley & Sons

 

Teaching methods

In-class lectures and exercises. Seminars by experts on specific topics. Laboratory activity and review of the final report.

Assessment methods

Oral examination. The examination will consist of two parts:

1) interview to evaluate student's knowledge about the physics principles and techniques of the particle detectors described in the course

2) discussion about the laboratory activity and review of the written report 

Teaching tools

Slides, blackboard, hands-on laboratory activities.

Office hours

See the website of Luigi Guiducci

See the website of Marco Selvi

See the website of Federica Primavera