Retrospective radon measurements based on implanted 210Po in glass objects using polycarbonate detectors

Abstract

1 De part ment of Med i cal Ra di a tion En gi neer ing, Sci ence and Re search Branch, Is lamic Azad Uni ver sity, Teh ran, Iran 2 Nu clear Sci ence and Tech nol ogy Re search In sti tute, Teh ran, Iran Sci en tific pa per http://doi.org/10.2298/NTRP1802167AIn the pres ent in ves ti ga tion, a sur face-de pos ited po lo nium was mea sured in 37 houses in Rasht and Ramsar cit ies of Iran with the aim of eval u at ing the ret ro spec tive ra don con cen tration. The CR-LR tech nique is widely used in this re gard, but for the first time, Lexan polycarbonate de tec tors were used to mea sure the ac tiv ity of 210 Po planted in glassy ob jects. These de tec tors were placed on glassy sur faces for 153 to 365 days. A pas sive cy lin dri cal dif fusion cham ber was used for the con tem po rary ra don con cen tra tion mea sure ments. The dif fusion cham ber con sists of the Lexan polycarbonate films as a solid state nu clear track de tec tors and fil ter. The sur face-de pos ited 210 Po ac tiv ity con cen tra tion was found to vary from 0.26 to 11.96 mBqcm -2 with av er age of 2.62 mBqcm -2 . The sen si tiv ity of 210 Po to polycarbonate was de ter mined to be 0.06456 track per cm 2 per mBqhcm -2 . Thus, the ra don con cen tra tion was found to vary from 122 to 4840 Bqm -3 with an av er age value 1243 Bqm -3 and the con tempo rary ra don con cen tra tion in the area was found to vary from 15 to 2420 Bqm -3 with an aver age 513 Bqm -3 . The re sults in di cate that there is a sig nif i cant cor re la tion be tween the concen tra tion of the ret ro spec tive ra don and the con cen tra tion of the con tem po rary ra don gas in the in di cated ar eas with a co ef fi cient of 0.80672.Key words: glassy ob ject, ret ro spec tive mea sure ment, po lo nium 210, polycarbonate de tec tor, ra don A. Azadbar, et al.: Ret ro spec tive Ra don Mea sure ments Based on Im planted 210 Po .