My work in NCT project

Jau-Shian LiangDepartment of Physics, NTHU / SSL, UCB2007/03/20

Nuclear Compton Telescope

( S. E. Boggs, CIS workshop 2005 @ NTHU )

( M. E. Bandstra, 2006 IEEE )

( E, x, y, z, t )

The left figure shows the classical COMPTEL type instrument.

The central picture shows a Compton telescope consisting of several thick layers in which the photon undergoes multiple Compton scatterings. The redundant scatter information allows to determine the direction of motion of the photon.

The right figure on the right shows an electron tracking Compton telescope like MEGA. The track of the electron determines the direction of motion of the photon.

Comparison of the different Compton telescopes

The 4 different event types of a tracking Compton and pair telescope

Left to right: Untracked Compton events; tracked Compton events; high-energy tracked Compton events with incomplete absorption; pair events.

Current Work

learning the MEGAlib for simulation and data analysis

MEGAlib(Medium Energy Gamma-ray Astronomy library)

A set of data analysis tools for modern Compton telescopes —from simulation/measurement via event reconstruction to image reconstruction

MEGAlib was originally written for data analysis of the MEGA Compton and Pair telescope

Simple Practice

two layers of Ge scintillators

511keV point source

1MeV ring shape source with 30 degree radius

to do the simulation of 511 keV line distribution with NCT mass model

Future Work

NCT mass model

Thank you