2 LOCKHART AND PATTERSON TABLE 1 Growth of Radon Daughters in a Fixed Volume of Air on Addition of Radon at the Rate of 104 Atoms per Minute rapsed Activit Atoms . (dis/min) CRAB. Activity Rauo (min) Rn* RaA RaB RaC Rn RaB (p) Ro/Ra’ 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 0 100,000 200,000| 300,000 400,000 500,000 600,000 700,000 800,000 900,000 1,000,000 1,100,000 1,200,000 1,300,000 1,400,000 1,500,000 1,600,000 1,700,000 1,800,000 0 36.0] 89.7] 145.0 200.4 255.7 311.1 366.5 421.8 477.2 532.6 588.0 643.3 698.7 754.1 809.5 864.9 920.3 975.7 0 30.8 1505] 3523] 618.7! 935.21 1290.4] 1675.4| 2083.5] 2509.4 2949.0 3399.3 3857.9 4329.8 4792.5 5266.1 5742.6 6221.3 |6701.8 0 22} 20.5] 69.3] 155.3| 279.91 441.2} 635.5| 858.8] 1106.9| 1375.9] 1662.0 1962.3} 2274.11 2595.2 2923.8 3258.3 3597.7 3940.8 0 1266] 25.33] 37.99] 50.66] 63.32] 75.98] 88.65| 101.31} 113.98 126.64] 139.30] 151.97] 164.63] 177.30 189.96 202.62 | 215.29 227.95 0 0.71 3.70| 8.82! 15.58] 23.71] 32.85] 42.76] 53.28] 64.271 75.62] 87.24} 99.08| 111.09] 123.2291 135.45] 147.77} 160.14} 172.54] — 0.071 0.136 0.197 0.251 0.299 0.342 0.379 0.412 0.441 0.467 0.489 0.509 0.526 0.542 0.555 0.567 0.578 0.588 — 17.9 6.85 4.31 3.95 2.67 2.31 2.07 1.901 1.773 1.675 1.597 1.534 1.482 1.439 1.402 1.371 1.344 1.321 *The smail amount of radon decay has been neglected. cae] i *' o8 4OF Orr a _ oa 3 ; % a a OS -- - ¢\ = « 230 \ o ma ~ <a 5 oO o © a2 or ~ 0 ° OF RADON \ ? \a ‘ \ \ SINGLE 4 EMISSION \, Ol a 4 CONTINUOUS EMISSION 4 <q 2.0}—- / \ \ Po 2 03 FS a aa 2 eo O4;- re a ' = a , 1 >» a 9 ; ' I \ \ a = 1 1 Q E < — O6r- \ OF RADON | | | 50 100 150 ELAPSED TIME (MINUTES) 10 200 Fig. 1 — Change in the RaC to RaB atom ratio (p) with the age of the radon conglomerate after exhalation of radon gas from the earth Oo “ | 50 “Ana Owhen ie | 100 ELAPSED TIME (MINUTES) 150 a . 200 Fig. 2 — Change in the radon to RaB activity ratio with the age of the radon conglomerate