Development of NTD Ge sensors for low temperature thermometry

Author

Mathimalar, S. ; Singh, V. ; Dokania, N. ; Nanal, V. ; Pillay, R.G. ; Pal, Shovon ; Ramakrishnan, Shankar ; Shrivastava, Ashish ; Maheshwari, Pushp ; Pujari, P.K. ; Oiha, S. ; Kaniilal, D. ; Jagadeesan, K.C. ; Thakare, S.V.

Author_Institution

India based Neutrino Obs., Tata Inst. of Fundamental Res., Mumbai, India

fYear

2014

fDate

7-9 July 2014

Firstpage

13

Lastpage

16

Abstract

The development of NTD Ge sensors for use in cryogenic bolometric detector to search for neutrinoless double beta decay (Ovββ) in ¹²⁴Sn is reported. The samples made from device grade Ge wafers are irradiated with thermal neutrons at Dhruva reactor, Bhabha Atomic Research Centre (BARC), Mumbai. The carrier concentration in irradiated Ge samples is estimated by Hall effect measurement at 77K. The fast neutron induced defects are studied using Positron Annihilation Lifetime Spectroscopy and Channeling. It is found that vacuum annealing of the samples at 600°C for 2 hours is necessary to cure the defects. Sensors are made from annealed NTD samples using Au-Ge Ohmic contact. Preliminary measurements have shown a significantly large dR/dT ~ 2.3 kΩ/mK at 100 mK. Details of these measurements are presented.

Keywords

Hall effect devices; annealing; bolometers; chemical variables measurement; cryogenics; double beta decay; germanium; germanium radiation detectors; ohmic contacts; positron annihilation; thermistors; thermometers; Bhabha Atomic Research Centre; Dhruva reactor; Ge; Hall effect measurement; NTD Ge sensors; Ohmic contact; annealed NTD samples; carrier concentration estimation; channeling; cryogenic bolometric detector; device grade Ge wafer; low temperature thermometry; neutrinoless double beta decay; neutron transmutation doped thermistor; positron annihilation lifetime spectroscopy; temperature 100 mK; temperature 600 K; temperature 77 K; thermal neutron; vacuum annealing; Annealing; Electrical resistance measurement; Neutrons; Semiconductor device measurement; Temperature measurement; Temperature sensors; Channeling; NTD Ge sensors; PALS;

fLanguage

English

Publisher

ieee

Conference_Titel

Low Temperature Electronics (WOLTE), 2014 11th International Workshop on

Conference_Location

Grenoble

Type

conf

DOI

10.1109/WOLTE.2014.6881014

Filename

6881014