### Abstract

Pixellated semiconductor detectors, such as CdZnTe, CdTe, or TlBr, are used for gamma-ray imaging in medicine and astronomy. Data analysis for these detectors typically estimates the position (x, y, z) and energy (E) of each interacting gamma ray from a set of detector signals {S_{i}} corresponding to completed charge transport on the hit pixel and any of its neighbors that take part in charge sharing, plus the cathode. However, it is clear from an analysis of signal induction, that there are transient signal on all pixel electrodes during the charge transport and, when there is charge trapping, small negative residual signals on all electrodes. If we wish to optimally obtain the event parameters, we should take all these signals into account. We wish to estimate x,y,z and E from the set of all electrode signals, {S_{i}(t)}, including time dependence, using maximum-likelihood techniques[1]. To do this, we need to determine the probability of the electrode signals, given the event parameters {x, y, z, E}, i.e. Pr( {S_{i}(t)} | {x, y, z, E} ). Thus we need to map the detector response of all pixels, {S_{i}(t)}, for a large number of events with known x,y,z and E.In this paper we demonstrate the existence of the transient signals and residual signals and determine their magnitudes. They are typically 50-100 times smaller than the hit-pixel signals. We then describe development of an apparatus to measure the response of a 16-pixel semiconductor detector and show some preliminary results. We also discuss techniques for measuring the event parameters for individual gamma-ray interactions, a requirement for determining Pr( {S _{i}(t)} | {x, y, z, E}).

Original language | English (US) |
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Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering |

Volume | 8143 |

DOIs | |

State | Published - 2011 |

Event | Medical Applications of Radiation Detectors - San Diego, CA, United States Duration: Aug 24 2011 → Aug 25 2011 |

### Other

Other | Medical Applications of Radiation Detectors |
---|---|

Country | United States |

City | San Diego, CA |

Period | 8/24/11 → 8/25/11 |

### Fingerprint

### Keywords

- CdTe
- CdZnTe
- CZT
- electronic readout
- induced signals
- pixel detectors
- Ramo's theorem
- semiconductor detector
- test apparatus
- TlBr

### ASJC Scopus subject areas

- Applied Mathematics
- Computer Science Applications
- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics

### Cite this

*Proceedings of SPIE - The International Society for Optical Engineering*(Vol. 8143). [81430P] https://doi.org/10.1117/12.898365

**Test apparatus to monitor time-domain signals from semiconductor-detector pixel arrays.** / Haston, Kyle; Barber, H. Bradford; Furenlid, Lars R; Salçin, Esen; Bora, Vaibhav.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*Proceedings of SPIE - The International Society for Optical Engineering.*vol. 8143, 81430P, Medical Applications of Radiation Detectors, San Diego, CA, United States, 8/24/11. https://doi.org/10.1117/12.898365

}

TY - GEN

T1 - Test apparatus to monitor time-domain signals from semiconductor-detector pixel arrays

AU - Haston, Kyle

AU - Barber, H. Bradford

AU - Furenlid, Lars R

AU - Salçin, Esen

AU - Bora, Vaibhav

PY - 2011

Y1 - 2011

N2 - Pixellated semiconductor detectors, such as CdZnTe, CdTe, or TlBr, are used for gamma-ray imaging in medicine and astronomy. Data analysis for these detectors typically estimates the position (x, y, z) and energy (E) of each interacting gamma ray from a set of detector signals {Si} corresponding to completed charge transport on the hit pixel and any of its neighbors that take part in charge sharing, plus the cathode. However, it is clear from an analysis of signal induction, that there are transient signal on all pixel electrodes during the charge transport and, when there is charge trapping, small negative residual signals on all electrodes. If we wish to optimally obtain the event parameters, we should take all these signals into account. We wish to estimate x,y,z and E from the set of all electrode signals, {Si(t)}, including time dependence, using maximum-likelihood techniques[1]. To do this, we need to determine the probability of the electrode signals, given the event parameters {x, y, z, E}, i.e. Pr( {Si(t)} | {x, y, z, E} ). Thus we need to map the detector response of all pixels, {Si(t)}, for a large number of events with known x,y,z and E.In this paper we demonstrate the existence of the transient signals and residual signals and determine their magnitudes. They are typically 50-100 times smaller than the hit-pixel signals. We then describe development of an apparatus to measure the response of a 16-pixel semiconductor detector and show some preliminary results. We also discuss techniques for measuring the event parameters for individual gamma-ray interactions, a requirement for determining Pr( {S i(t)} | {x, y, z, E}).

AB - Pixellated semiconductor detectors, such as CdZnTe, CdTe, or TlBr, are used for gamma-ray imaging in medicine and astronomy. Data analysis for these detectors typically estimates the position (x, y, z) and energy (E) of each interacting gamma ray from a set of detector signals {Si} corresponding to completed charge transport on the hit pixel and any of its neighbors that take part in charge sharing, plus the cathode. However, it is clear from an analysis of signal induction, that there are transient signal on all pixel electrodes during the charge transport and, when there is charge trapping, small negative residual signals on all electrodes. If we wish to optimally obtain the event parameters, we should take all these signals into account. We wish to estimate x,y,z and E from the set of all electrode signals, {Si(t)}, including time dependence, using maximum-likelihood techniques[1]. To do this, we need to determine the probability of the electrode signals, given the event parameters {x, y, z, E}, i.e. Pr( {Si(t)} | {x, y, z, E} ). Thus we need to map the detector response of all pixels, {Si(t)}, for a large number of events with known x,y,z and E.In this paper we demonstrate the existence of the transient signals and residual signals and determine their magnitudes. They are typically 50-100 times smaller than the hit-pixel signals. We then describe development of an apparatus to measure the response of a 16-pixel semiconductor detector and show some preliminary results. We also discuss techniques for measuring the event parameters for individual gamma-ray interactions, a requirement for determining Pr( {S i(t)} | {x, y, z, E}).

KW - CdTe

KW - CdZnTe

KW - CZT

KW - electronic readout

KW - induced signals

KW - pixel detectors

KW - Ramo's theorem

KW - semiconductor detector

KW - test apparatus

KW - TlBr

UR - http://www.scopus.com/inward/record.url?scp=80054884990&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80054884990&partnerID=8YFLogxK

U2 - 10.1117/12.898365

DO - 10.1117/12.898365

M3 - Conference contribution

AN - SCOPUS:80054884990

SN - 9780819487537

VL - 8143

BT - Proceedings of SPIE - The International Society for Optical Engineering

ER -