Project laborations in SH2306, HT08

Experimental Techniques for Nuclear and Particle Physics

1) Rayleigh scattering of gamma-rays

The laboratory exercise is dedicated to the study of elastic scattering of gamma-rays off high-Z targets. At low energies (60 keV) the scattering is governed by electrons tightly bound in the atomic shells and it is then called Rayleigh scattering. The task is to identify Rayleigh scattering to measure its angular distribution. The coherent character of the scattering process can be revealed from the measured distribution.

Monte-Carlo simulations of the experimental setup are necessary for controlling the geometrical factors.

Opponent group for group no. 2

Group members: MARCKS VON WÄRTEMBERG KLAS

MARTEINSDOTTIR MARIA

MC workshops: October 28, 13:00-17, November 4, 13:00-17

Supervisor: Stanislav Tashenov

2) Compton scattering of gamma-rays on bound atomic electrons: Compton profile.

Inelastic scattering of gamma-rays from bound electrons is often discussed within the so-called Impulse Approximation when the electrons are considered to be free with the initial distribution of their velocities, depending on the atomic shells. An averaged momentum distribution of the electrons, called Compton profile, manifests itself as broadened scattering energy peaks. These Compton-broadened peaks are measured for different materials and energies. Monte-Carlo studies will be required to identify the suitable experimental geometry.

Opponent group for group no. 3

Group members: DE GÓMEZ-SELLÉS ORTUÑO JOSÉ LUIS

JURADO MANUEL GARCIA

AKTER SANIZ

MC workshops: October 21, 13:00-17, October 23, 13:00-17

Supervisor: Stanislav Tashenov

3) Detector-related background distributions in gamma-ray spectroscopy

The interaction of gamma-rays with matter (detectors) is governed by photoelectric, Compton scattering, pair production and Bremsstrahlung processes. In the ideal situation the full energy of the incoming photon is absorbed in the detector resulting in a well isolated full-energy peak (“photopeak”). It requires the full absorption of the secondary photons and electrons produced by these processes. The complex structure of the energy spectrum, resulting from partial photon escapes, should be well understood by every experimentalist. Scintillation detectors based on different materials and geometries are tested and their properties measured.Monte-Carlo studies of the detector response to gamma-rays should be performed and compared with the laboratory measurements.

Opponent group for group no. 4

Group members: UDDIN HOSSAIN MA

MA YUAN

REZA MD SHAWON HASAN

MC workshops: October 28, 13:00-17, October 31, 13:00-17

Supervisors: Anton Khaplanov and Wlodek Klamra

4) Compton scattering angular distribution

Compton scattering – scattering of photons on quasi-free electrons is the dominant and simplest photon-matter interaction process in the energy region of few 100 keV up to few MeV. The laboratory measurement of the Compton scattering cross section should be performed. Its angular distribution is to be measured and compared with the theoretical Klein-Nishina formula.

Opponent group for group no. 5

Group members: RÖLLIG MARCO

KEHRER BENJAMIN ULI

HUSSAIN AAMIR

MC workshops: October 31, 13:00-17, November 4, 13:00-17

Supervisor: Per-Erik Tegner

5) Magnetic Compton scattering

The photon helicity – projection of the photon angular momentum on its momentum direction, also called photon circular polarization, is a fundamental property of photons which is very hard to measure. The measurement of photon helicity is essential for the studies of parity non-conservation effects in particular for the search of new physics beyond the Standard Model. Compton scattering of the gamma-rays off polarized electrons depends on their spin orientation with respect to the photon helicity. In the region where Compton scattering dominates, spin polarized (magnetized) targets can provide means for the gamma-ray circular polarimetry. In the laboratory exercise the circularly polarized photon beam will be produced and analyzed by means of strong permanent magnets. A Monte-Carlo simulation of the set-up is performed.

Opponent group for group no. 5

Group members: WIKSTRÖM GUSTAV

ERICSSON PATRICK

MC workshops: October 30, 13:00-17, November 6, 13:00-17

Supervisor: Stanislav Tashenov

For all laboratory exercises GEANT4 Monte-Carlo simulations will be performed. Supervisors are Stanislav Tashenov and Anton Khaplanov. The simulations will be performed on two dedicated computers at the Nuclear Physics Department, KTH, 3^rd floor, AlbaNova.

IMPORTANT:

The written project report should be handed in at the latest at the lecture on November 28, 2008. Contact your supervisor and agree on a date when you will meet to discuss it and receive comments. The modified report shall then be ready and back to your supervisor and to your opponent group by noon, December 5, 2008.

Also make sure that you have the project report from the group for which you are opponent (see above) by December 5, 2008. You can get the report from the supervisor or directly from the students.

Oral presentations of the lab projects will take place on Monday December 8, 10 – 12 in FA31, AlbaNova.

In the presentation session each group will have prepared 4 critical questions (in a positive spirit!) on the report submitted by the group for which they are opponent. Additional questions from anyone that arise during the presentations are very much encouraged. We want to have a lively discussion on the different projects after each presentation.

Supervisor email addresses:

Anton Khaplanov: anton@nuclear.kth.se

Stanislav Tashenov: tashenov@nuclear.kth.se

Wlodek Klamra: klamra@particle.kth.se

Per-Erik Tegner: tegner@physto.se