Browse Prior Art Database

PULSE SHAPE DISCRIMINATION FOR ENERGY RESOLVING SEMICONDUCTOR RADIATION DETECTORS

IP.com Disclosure Number: IPCOM000199445D
Publication Date: 2010-Sep-04
Document File: 6 page(s) / 124K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present invention discloses a pulse shape discrimination system used in energy resolving semiconductor radiation detectors. The pulse shape discrimination system comprises a semiconductor sensor and a charge sensitive preamplifier connected to an analog to digital conversion system, wherein the analog to digital conversion system is configured for a speed that fully captures the preamplifier output. The pulse shape discrimination system is configured for determining the energy of a single x-ray or gamma photon accurately and, is energy independent and simple to implement.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 38% of the total text.

Page 1 of 6

    RP13481

 

PULSE SHAPE DISCRIMINATION FOR ENERGY RESOLVING SEMICONDUCTOR RADIATION DETECTORS

BRIEF ABSTRACT

    The present invention discloses a pulse shape discrimination system used in energy resolving semiconductor radiation detectors. The pulse shape discrimination system comprises a semiconductor sensor and a charge sensitive preamplifier connected to an analog to digital conversion system, wherein the analog to digital conversion system is configured for a speed that fully captures the preamplifier output. The pulse shape discrimination system is configured for determining the energy of a single x-ray or gamma photon accurately and, is energy independent and simple to implement.

KEYWORDS

    Pulse Shape Discrimination, Energy Resolving Semiconductor Radiation, X-ray, gamma photon, acquired pulse shape, detect events, semiconductor sensor, a charge sensitive preamplifier, analog to digital (A-D) conversion system, energy independent single parametric pulse, measurement with calibration sources

DETAILED DESCRIPTION

    Typical semiconductor radiation detectors, such as CdZnTe, CdTe and HgI2 detectors directly convert radiation interacting in the active volume into electron-hole pairs. All charges created in the semiconductor do not migrate directly to the electrode and the charges can be trapped in the semiconductor. A disadvantage of the typical semiconductor radiation detector is that the mobility of holes is lower than that of electrons. All the charges created do not contribute to the measured detection signal that results in an energy resolution far worse than theoretically expected. Generally,

Page 2 of 6

    RP13481

 

energy resolution is defined as the width at half maximum of a distribution of energy peak around emission energy value divided by the emission energy.

    Aforementioned problems of the typical semiconductor radiation detector have been addressed using various techniques. One conventional technique is a single charge sensing. The single charge sensing proposes a special electrode structure similar to Frisch grids to exclusively collect electrons and not holes. As electrons are less prone to trapping, performance is improved. Another conventional technique is a bi-parametric correction method. The bi-parametric correction method is a complex method that uses hardware to determine the rise time of pulses and their energy. In accordance with a first step of the bi-parametric correction technique, a digital circuit or a computer is used to check whether recorded pulse energies and rise times fall into an acceptance window. If recorded pulse energies and rise time do not fall into an acceptance window in accordance with a mapping of the bi-parametric space, the pulse is discarded or corrected in terms of its energy. The rise time is energy dependant and the algorithm leads to a change in the peak height ratios (may also be referred to as 'energy dependant sensitivity') over the energy measurement range of the detect...