PHYS 841

 

Experimental Methods for Particle Astrophysics

 

Course Description:

 

An introduction to experimental techniques employed in modern particle astrophysics experiments. Topics will include a description of the interactions of particles with matter and the detection techniques for topics of current interest, including neutrinos, dark matter, double beta decay and supernovae.

 

 

Course Outline:

 

This term the course is being organized as a reading course. The course is a 6 week module. We will meet twice per week to discuss the reading assignments.  It is expected that at some of the meetings questions will be posed that require further research. This will then be followed up in the next meeting. The first such meetings will begin the week of Jan 15th. The dates and times for the meetings will be defined by January 8th, by mutual agreement.

 

The course will cover technical details for experiments in astroparticle physics. The discussion should cover items including:

·     How do the detectors work? What are the physical principles?

·     How are they specialized for particle astrophysics?

·     What is the expected physics output of the experiments currently under consideration.

 

 

Suggested Reading Assignments:

 

Twelve topics should be selected from the list below. The first 8 are “compulsory topics” The remaining 4 can be selected according to the interest of the student. Also, other topics may be researched instead, with the permission of the instructor. Please provide at least one week advance notice to the instructor of the topic currently being researched.

 

Compulsory List:

 

  1. Time Projection Chambers: as envisioned for the T2K neutrino oscillation experiment, including relative pros and cons of GEM and Micromegas readout systems. See for example www-tpc.lbl.gov/workshop06

 

  1. Liquid Noble Gas detectors: as for example the Zeplin detectors. (Or Xenon, or the now combined effort LUX). Include discussion on ionization verses scintillation, and how they are produced. Also discuss pulse shape discrimination and considerations that go into the selection of noble gas.

 

  1. Solid state detectors: High Purity Germanium. As for example the GERDA double-beta decay experiment. Discuss the types of germanium, doping, purity, isotopic enrichment and segmentation.

 

  1. Cryogenic “Zip” detectors as in CDMS: Explain how these dual purpose detectors work, how the phonons are produced and detected, how the charge is collected, how the transition edge detectors work and what the SQUIDs role is. What are the features of this detector technology that has led it to being the world leader in dark matter searches to date? 

 

  1. NaI Detectors. Describe principle of operation for inorganic scintillators like NaI. Using NaIAD as an example, describe the pros and cons of this detector type with regards to dark matter searches.

 

  1. Using the NEMO-3 double beta decay experiment as an example, explain how drift tubes operate, and their use in Geiger mode. See the NEMO web site, and their NIM paper: http://nemo.in2p3.fr/nemodocs/nemo/public/NIM_NEMO3.pdf What is the physics potential for NEMO-3, and what are the plans for Super NEMO?

 

  1. Very Low background techniques. What are the main sources of radioactive backgrounds that plague dark matter, low energy solar neutrino and double beta decay experiments? Describe techniques to mitigate against these backgrounds, and techniques to measure ultra low levels of radioactivity. See proceedings of the Low Radioactivity Techniques workshop http://lrt2004.snolab.ca/

 

  1. Neutrons are a common problem for many astroparticle physics experiments. Explain how neutrons can be produced in deep underground laboratories. Discuss shielding strategies, and techniques that may be used measure both fast and thermal neutrons.

 

Electives List: Select any four.

 

  1. Water Cerenkov Detectors for high energy neutrinos: As an example, the Antares or IceCube experiment. Consider wavelength and amount of light produced and how that affects the design, energy thresholds, angular resolution (pointing accuracy), energy resolution and hence comment on the scientific reach of these experiments. Comment also on potential for indirect dark matter detection.

 

  1. Air Shower arrays. For example the Auger experiment. How do detectors work, how are showers detected, what are the angular and energy resolution? Comment on the scientific reach of these experiments. How does Auger compare to Hess or Veritas in terms of physics potential and technique?

 

  1. Dark matter searches: Machos. For example the EROS-1 and EROS-2 searches for dark matter candidates in the LMC. How do these micro-lensing experiments work? What limits can they put on dark matter. How do the results compare with the MACHO collaboration results?

 

  1. Dark matter searches: Axions. What are axions? How are they motivated in particle physics theories? Using the CAST experiment as an example, explain the detection techniques and expected sensitivities.

 

  1. Comment on the technique of microlensing, and how that was used in the bullet cluster collisions cited as direct evidence for dark matter. See for example the paper: http://arxiv.org/PS_cache/astro-ph/pdf/0608/0608407.pdf

 

  1. Crystal Bolometers for dark matter detection. Eg NaF or LiF. How do these detectors work? What are their limitations/advantages?

 

  1. HALO proposes to use lead and 3He counters to look for supernova neutrinos. This is similar to the LAND proposal which would have used Lead and BF3 counters. Explain how this detector technology would work.