Estimating thickness of the inner dead-layer of n-type HPGe detector

Huynh Dinh Chuong; Tran Thien Thanh; Le Thi Ngoc Trang; Vo Hoang Nguyen; Chau Van Tao

doi:10.1016/j.apradiso.2016.08.010

Estimating thickness of the inner dead-layer of n-type HPGe detector

Appl Radiat Isot. 2016 Oct:116:174-7. doi: 10.1016/j.apradiso.2016.08.010. Epub 2016 Aug 15.

Authors

Huynh Dinh Chuong¹, Tran Thien Thanh², Le Thi Ngoc Trang¹, Vo Hoang Nguyen³, Chau Van Tao⁴

Affiliations

¹ Nuclear Technique Laboratory, VNUHCM-University of Science, 227, Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam.
² Nuclear Technique Laboratory, VNUHCM-University of Science, 227, Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam; Department of Nuclear Physics, Faculty of Physics and Engineering Physics, VNUHCM-University of Science, 227, Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam. Electronic address: ttthanh@hcmus.edu.vn.
³ Department of Nuclear Physics, Faculty of Physics and Engineering Physics, VNUHCM-University of Science, 227, Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam.
⁴ Nuclear Technique Laboratory, VNUHCM-University of Science, 227, Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam; Department of Nuclear Physics, Faculty of Physics and Engineering Physics, VNUHCM-University of Science, 227, Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam.

PMID: 27552123
DOI: 10.1016/j.apradiso.2016.08.010

Abstract

In this study, a procedure to estimate thickness of the inner dead-layer of an n-type coaxial HPGe detector is described. Experimental measurements are carried out with standard point sources: (54)Mn, (57)Co, (60)Co, (88)Y, (109)Cd, (134)Cs, (137)Cs, and (152)Eu at distances of 5 and 10cm from source to detector. Shape and dimensions of a high-purity germanium (HPGe) detector are determined by radiography to characterize the geometry accurately for Monte Carlo simulation. The role of thickness of the inner dead-layer on full energy peak efficiency is illustrated by MCNP5 code, and it is observed that slope coefficient of efficiency curve has a linear relationship with thickness of the dead-layer. The adjustment of dead-layer yields good agreement, with relative deviation of ≤3%, between experimental efficiency and simulated efficiency in the energy range of 88-1836keV.

Keywords: HPGe, dead-layer; MCNP5; Radiography.