# 지표공기중(地表空氣中)의 ${\alpha}$ 방사능측정(放射能測定) 및 해석(解析)

• Jun, Jae-Shik (Department of Physics, Chungnam National University) ;
• Myung, Dong-Bun (Department of Physics, Chungnam National University)
• 전재식 (충남대학교 이과대학 물리학과) ;
• 명동범 (충남대학교 이과대학 물리학과)
• Published : 1986.12.15

#### Abstract

A study on the measurement of alpha activity in ground air has been carried out using CA 80-15 and LR 115-1 cellulose nitrate nuclear track detectors. The detection efficiency of the detectors were determined by making use of an $^{241}Am$ alpha source of $0.1{\mu}Ci$ in activity under a known geometrical arrangement. For the field measurement of alpha activity of emanated radon and its progeny in ground air two different radon cups were installed for a certain period of time in two neighbouring ground holes of about 15 cm in diameter and 45 cm in depth. Of the two radon cups one kept closed space during the detecting period, while the other kept open space with a hole enabling the air to ventilate. The etched tracks were read out by a microscope and the results obtained through statistical analysis were evaluated in terms of alpha activity per unit volume of air.