Gamma background measurements in the Boulby Underground Laboratory

Area of Science:

• Nuclear Physics
• Environmental Science
• Geophysics

Background:

• Underground laboratories require precise knowledge of background radiation.
• Natural radioactivity in surrounding rock formations can influence experimental sensitivity.

Purpose of the Study:

• To quantify in situ gamma-ray emissions at the Boulby Underground Laboratory.
• To assess background radiation levels for experimental planning.

Main Methods:

• In situ gamma-ray spectrometry was employed at ten distinct locations.
• Activity concentrations of uranium and thorium in surrounding rocks (halite, mudstone) were analyzed.

Main Results:

• Gamma-ray counts ranged from 6.5 to 28 γ s⁻¹ within the 7-2,734 keV energy range.
• The arithmetic mean for gamma radiation inside the laboratory was 24 γ s⁻¹.
• Uranium and thorium concentrations in surrounding sedimentary rocks were found to be very low.

Conclusions:

• The Boulby Underground Laboratory exhibits low background radiation levels.
• The characterized low-activity rock formations (halite, mudstone) contribute to a stable experimental environment.