G-M 계수관과 137Cs 선원을 이용한 납 반가층의 실험적 연구

HVL (half-value layer) of lead was measured experimentally using a lead and 137Cs (370 kBq) source and a G-M counter in which is used a lot of material for shielding HVL measured. 137Cs in holder to 10 cm and start measuring the radiation. Continue addition of lead of the lead thickness of 1 mm one by one to continue the measurement. By measuring four times the natural radiation of 100 seconds and records the count value and the average rate to be displayed on the meter. Background radiation was a 4 times a count rate and the average 108 (100 s-1) as a result of measuring the average measurement, the standard deviation was determined to be 1.08 (s-1). An increase in the thickness of lead initial count rate starting from 920 (N) count rate is decreased with increase in the thickness of lead. Net counting rate, starting with the initial 8.12 (s-1) showed a decrease with increasing thickness, the standard deviation of the results was decreased from 0.303 (s-1) to 0.196 (s-1). Net counting rate is reduced to obtain the result that each half thickness of nappan about 7 mm. Was reduced similarly to the exponential function graph correlation coefficient (R2) was found to be 0.9869. Half-value layer which is the initial net counting rate 7.514 (s-1) is a half the 7 mm to 3.757 (s-1). In conclusion, it was confirmed the theoretical HVL of lead 7.19 mm and experimentally measured results matched the measured HVL 7 mm.