Gamma background measurements in the Gran Sasso National Laboratory

Dariusz Malczewski,Jan Kisiel,Jerzy Dorda

doi:10.1007/s10967-012-1990-9

Dariusz Malczewski, Jan Kisiel + Show 1 more

Open Access

https://doi.org/10.1007/s10967-012-1990-9

Copy DOI

Abstract

In situ gamma-ray measurements were taken at eight locations in the Gran Sasso National Laboratory (Italy). Count rates for gamma radiation within the energy range of 7–2,734 keV varied from 8 to 60 γ s−1. The arithmetic mean was 49 γ s−1 for measurements taken without a collimator. The average gamma flux inside the Lab was 0.25 γ cm−2 s−1. The sedimentary rocks surrounding the Lab are characterized by low activity concentrations of uranium and thorium, equal to 1.7 and 1.4 Bq kg−1, respectively.

Highlights

The Gran Sasso National Laboratory (Laboratori Nazionali del Gran Sasso—LNGS) is one of the largest and most important underground research centers in the world
The most important sources of background radiation include the decay of primordial radionuclides, such as 40K, 232Th, and 238U in rock, concrete, and the construction materials used in the detectors
In this paper we present results of in situ gamma-ray measurements in the LNGS, which were performed in 2007, and laboratory measurements of the parent rock and concrete covering the tunnels

Summary

Introduction

The Gran Sasso National Laboratory (Laboratori Nazionali del Gran Sasso—LNGS) is one of the largest and most important underground research centers in the world. The Laboratory is composed of three large underground halls that have been excavated in the Gran Sasso Massif (central Italy). Dorda Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland detection, and their sensitive experiments require an environment shielded from high energy cosmic rays [2]. As the Laboratory is deep underground, a thick layer of overlaying rocks effectively blocks the strongly interacting cosmic rays from entering the underground halls where the experiments are run. The most important sources of background radiation include the decay of primordial radionuclides, such as 40K, 232Th, and 238U in rock, concrete, and the construction materials used in the detectors. The neutrons originating from (a, n) reactions and the spontaneous fission of U and Th are the main sources of background radiation, which can imitate some of the expected signals from physics experiments [3, 4]

Methods

Results

Conclusion