HPGE RADIATION DETECTORS TECHNOLOGY Krzysztof Panas Jagiellonian - - PowerPoint PPT Presentation

HPGE RADIATION DETECTORS TECHNOLOGY

Krzysztof Panas

Jagiellonian University, Poland

Supervisor: Dariusz Borowicz

Laboratory of Nuclear Problems, JINR 25th of July 2014, JINR Dubna

Presentation agenda

1.

Introduction

2.

Geometry of the detector

3.

Measurements:

1.

Reverse current

2.

Energy resolution

4.

Acknowledgements

Introduction

 High purity germanium detectors (HPGe) - best energy

resolution among all detector types

 In principle, they work like reverse biased diodes; energy

deposition by nuclear radiation causes flow of a current, which is processed by front-end electronics

 The aim of the project was to measure the performance

• f small-contact large volume HPGe detector

manufactured in JINR

Geometry of the detector

• Fig. Geometrical dimensions of the

investigeted detector (in mm)

Source: Brudanin, V. B., et al. "Large-volume HPGe detectors for rare events with a low deposited energy." Instruments and Experimental Techniques 54.4 (2011): 470-472.

• Fig. Photography of the investigated

detector

Reverse current measurements

 Reverse (dark) current – a current flowing through

the detector while it is reverse biased

2 4 6 8 10 12 14 500 1000 1500 Reverse current I [nA] Bias voltage U [V] After cleaning Before cleaning

Energy resolution measurements

• Fig. Co-60 spectrum measured with „warm” preamplifier @ U = 800 V.

Energy resolution measurements cont’d

• Fig. Measured FWHM of the Co-60 1332 keV peak.

Energy resolution measurements cont’d

• Fig. Co-60 spectrum measured with „cold” preamplifier @ U = 800 V.

Energy resolution measurements cont’d

• Fig. Measured FWHM of the Co-60 1332 keV peak.

Acknowledgements

 To:

 dr Władysław Chmielewski and dr hab. Roman

Zawodny

 University Centre director dr Stanislav Z. Pakuliak  Dariusz Borowicz