Difference between revisions of "Solutions 2"
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#<sup>228</sup>Ac, <sup>220</sup>Rn,<sup>216</sup>Po, <sup>212</sup>Pb, <sup>212</sup>Bi, <sup>212</sup>Po. <br> | #<sup>228</sup>Ac, <sup>220</sup>Rn,<sup>216</sup>Po, <sup>212</sup>Pb, <sup>212</sup>Bi, <sup>212</sup>Po. <br> | ||
− | <br> | + | <br> |
− | '''2:'''<br> | + | '''2:'''<br> |
− | #When T= 0 it's only the natural isotopes of uranium: <sup>238</sup>U, <sup>235</sup>U and <sup>234</sup>U. | + | #When T= 0 it's only the natural isotopes of uranium: <sup>238</sup>U, <sup>235</sup>U and <sup>234</sup>U. |
− | #D(<sup>238</sup>U)=D(<sup>234</sup>U)<math>\approx</math> 12.5 kBq, D(<sup>235</sup>U) = 575 Bq. | + | #D(<sup>238</sup>U)=D(<sup>234</sup>U)<math>\approx</math> 12.5 kBq, D(<sup>235</sup>U) = 575 Bq. |
− | #When t = 23.5 h there is created some <sup>234</sup>Th and some <sup>234</sup>Pa, but creation of other daugthers from <sup>238</sup>U is negligible. From the <sup>235</sup>U there is created<sup>231</sup>Th<br> | + | #When t = 23.5 h there is created some <sup>234</sup>Th and some <sup>234</sup>Pa, but creation of other daugthers from <sup>238</sup>U is negligible. From the <sup>235</sup>U there is created<sup>231</sup>Th<br> |
#D(<sup>238</sup>U) = D(<sup>234</sup>U) =D0, <br>D(<sup>234</sup>Th) = D(<sup>234</sup>Pa) = 376 Bq,<br>D<sup>(235</sup>U) = D0,<br>D(<sup>231</sup>Th) = 287.5 Bq.<br> | #D(<sup>238</sup>U) = D(<sup>234</sup>U) =D0, <br>D(<sup>234</sup>Th) = D(<sup>234</sup>Pa) = 376 Bq,<br>D<sup>(235</sup>U) = D0,<br>D(<sup>231</sup>Th) = 287.5 Bq.<br> | ||
#When t = 23 days the same radionuclides are present.<br> | #When t = 23 days the same radionuclides are present.<br> | ||
− | #D(<sup>238</sup>U) = D<sup>(234</sup>U) =D<sub>0</sub>, <br>D(<sup>234</sup>Th) = D(<sup>234</sup>Pa) = 6250 Bq,<br>D(<sup>235</sup>U) = D<sub>0</sub>,<br>D(<sup>231</sup>Th) = D(<sup>235</sup>U) =575 Bq. <br> | + | #D(<sup>238</sup>U) = D<sup>(234</sup>U) =D<sub>0</sub>, <br>D(<sup>234</sup>Th) = D(<sup>234</sup>Pa) = 6250 Bq,<br>D(<sup>235</sup>U) = D<sub>0</sub>,<br>D(<sup>231</sup>Th) = D(<sup>235</sup>U) =575 Bq. <br> |
− | # | + | #When t = 1.0 y the same radionuclides are present.<br> |
− | ## | + | #D(<sup>238</sup>U) = D(<sup>234</sup>U) =D<sub>0</sub>, <br>D(<sup>234</sup>Th) = D(<sup>234</sup>Pa) = D<sup>(238</sup>U) = 12,5 kBq,<br>D(<sup>235</sup>U) = D<sub>0</sub>,<br>D(<sup>231</sup>Th) = D(<sup>235</sup>U) =575 Bq.<br> |
− | # <br> | + | #When t = 1.0 y the same radionuclides are present.<br> |
+ | # <br> | ||
#<br> | #<br> | ||
<br> | <br> |
Revision as of 10:54, 19 June 2012
1:
- 1000g Th(NO3)4 = 2.083 mol arrow N(Th)= 1.25 1024 atoms. This is natural thorium, where the equilibrium in Th-series will lead to equal aktivity of 232Th and 228Th. Since 232Th has a incredibly long half-life and 228Th is short compared to this and we can approximate N(Th) N(232Th)=1.25 10^24 The disintegration for both is 1.96 106Bq.
- 6.43 10-8g
- 10000 Bq 228Ra = 2.62 1012 atoms = 90% arrow 100% 2.92 1012 atoms. If 232Th is N1 and 228Ra is N2 we can use the formulas for mother/daughter realations: Alternatively it can be solved by using D(228Ra) = 11 111Bq:
- 224Ra is created from 228Th immeasurable amounts of 228Th is created in three days, creation of new 224Ra can therefore be ignored. D0(224Ra)=D0(228Th)=1.36
106 Bg, and we get a normal decay: - 228Ac, 220Rn,216Po, 212Pb, 212Bi, 212Po.
2:
- When T= 0 it's only the natural isotopes of uranium: 238U, 235U and 234U.
- D(238U)=D(234U) 12.5 kBq, D(235U) = 575 Bq.
- When t = 23.5 h there is created some 234Th and some 234Pa, but creation of other daugthers from 238U is negligible. From the 235U there is created231Th
- D(238U) = D(234U) =D0,
D(234Th) = D(234Pa) = 376 Bq,
D(235U) = D0,
D(231Th) = 287.5 Bq.
- When t = 23 days the same radionuclides are present.
- D(238U) = D(234U) =D0,
D(234Th) = D(234Pa) = 6250 Bq,
D(235U) = D0,
D(231Th) = D(235U) =575 Bq.
- When t = 1.0 y the same radionuclides are present.
- D(238U) = D(234U) =D0,
D(234Th) = D(234Pa) = D(238U) = 12,5 kBq,
D(235U) = D0,
D(231Th) = D(235U) =575 Bq. - When t = 1.0 y the same radionuclides are present.
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