Template talk:Ra to Es by HL
I have an idea. If you take the log of the HL, you'll get values from just over 0 to just over 10. One could do a greyscale for that...
HL log HL 16 – log HL *16 -1 DEC2HEX 1 0 16 255 FF 10 1 15 239 EF 100 2 14 223 DF 1000 3 13 207 CF 10000 4 12 191 BF 100000 5 11 175 AF 1000000 6 10 159 9F 10000000 7 9 143 8F 100000000 8 8 127 7F 1000000000 9 7 111 6F 10000000000 10 6 95 5F
For the scale. -- Limulus (talk) 22:57, 9 July 2013 (UTC)
Isotope HL (a) log HL 16-log HL *16 -1 DEC2HEX 235Np 1.084 0.035 15.965 254 FE 252Es 1.291 0.111 15.889 253 FD 228Th 1.9116 0.281 15.719 250 FA 252Cf 2.645 0.422 15.578 248 F8 236Pu 2.858 0.456 15.544 248 F8 228Ra 5.75 0.760 15.240 243 F3 250Cf 13.08 1.117 14.883 237 ED 241Pu 14.29 1.155 14.845 237 ED 244Cm 18.1 1.258 14.742 235 EB 227Ac 21.772 1.338 14.662 234 EA 243Cm 29.1 1.464 14.536 232 E8 232U 68.9 1.838 14.162 226 E2 238Pu 87.7 1.943 14.057 224 E0 242mAm 141 2.149 13.851 221 DD 249Cf 351 2.545 13.455 214 D6 241Am 432.2 2.636 13.364 213 D5 251Cf 900 2.954 13.046 208 D0 247Bk 1380 3.140 12.860 205 CD 226Ra 1600 3.204 12.796 204 CC 246Cm 4760 3.678 12.322 196 C4 240Pu 6561 3.817 12.183 194 C2 229Th 7340 3.866 12.134 193 C1 243Am 7370 3.867 12.133 193 C1 250Cm 8300 3.919 12.081 192 C0 245Cm 8500 3.929 12.071 192 C0 239Pu 24110 4.382 11.618 185 B9 231Pa 32760 4.515 11.485 183 B7 230Th 75380 4.877 11.123 177 B1 236Np 154000 5.188 10.812 172 AC 233U 159200 5.202 10.798 172 AC 234U 245500 5.390 10.610 169 A9 248Cm 348000 5.542 10.458 166 A6 242Pu 375000 5.574 10.426 166 A6 237Np 2144000 6.331 9.669 154 9A 247Cm 15600000 7.193 8.807 140 8C 236U 23420000 7.370 8.630 137 89 244Pu 80000000 7.903 8.097 129 81 235U 704000000 8.848 7.152 113 71 238U 4468000000 9.650 6.350 101 65 232Th 14050000000 10.148 5.852 93 5D
-- Limulus (talk) 21:10, 9 July 2013 (UTC)
- An oversight! "248Bk [...] >9 a" so:
248Bk 9 0.954 15.046 240 F0
-- Limulus (talk) 10:16, 26 January 2014 (UTC)
- [1] (probably source of ">9 a") states that "the alpha half-life is probably greater than 300 y" ("and a lower limit for the β− half-life can be set at about 104 y") so let's use 300.
248Bk 300 2.477 13.523 215 D7
-- Limulus (talk) 10:59, 26 January 2014 (UTC)
Decay modes
Decay modes, from File:NuclideMap stitched.png and Isotopes_of_americium#Americium-242m:
Isotope HL (a) Normal Decay Mode(s) 235Np 1.084 electron capture 252Es 1.291 alpha (78%), electron capture (22%) 228Th 1.9116 alpha 252Cf 2.645 alpha (96.91%), spontaneous fission (3.09%) 236Pu 2.858 alpha 228Ra 5.75 beta- 250Cf 13.08 alpha (99.92%), spontaneous fission (0.08%) 241Pu 14.29 beta- 244Cm 18.1 alpha 227Ac 21.772 beta- (98.62%), alpha (1.38%) 243Cm 29.1 alpha (99.71%), electron capture (0.29%) 232U 68.9 alpha 238Pu 87.7 alpha 242mAm 141 isomeric transiton (99.54%), alpha (0.46%) 248Bk >300? alpha 249Cf 351 alpha 241Am 432.2 alpha 251Cf 900 alpha 247Bk 1380 alpha 226Ra 1600 alpha 246Cm 4760 alpha (99.7%), spontaneous fission (0.3%) 240Pu 6561 alpha 229Th 7340 alpha 243Am 7370 alpha 250Cm 8300 spontaneous fission (74%), alpha (18%) 245Cm 8500 alpha 239Pu 24110 alpha 231Pa 32760 alpha 230Th 75380 alpha 236Np 154000 electron capture (86.3%), beta- (13.5%) 233U 159200 alpha 234U 245500 alpha 248Cm 348000 alpha (91.61%), spontaneous fission (8.39%) 242Pu 375000 alpha 237Np 2144000 alpha 247Cm 15600000 alpha 236U 23420000 alpha 244Pu 80000000 alpha 235U 704000000 alpha 238U 4468000000 alpha 232Th 14050000000 alpha
Observations:
- Beta/EC in relatively short HL isotopes; < 22y EXCEPT Np-236...
- 242mAm a special case. Setting the HL cut-off > 141y would get rid of that.
- Long half lives pretty much all alpha exclusively; spontaneous fission increasingly happens in the heavier isotopes (246+).
-- Limulus (talk) 04:11, 18 February 2014 (UTC)
Mass number
Arranged by mass number; note isobars for several:
226Ra 1600 227Ac 21.772 228Ra 5.75 228Th 1.9116 229Th 7340 230Th 75380 231Pa 32760 232Th 14050000000 232U 68.9 233U 159200 234U 245500 235U 704000000 235Np 1.084 236U 23420000 236Np 154000 236Pu 2.858 237Np 2144000 238U 4468000000 238Pu 87.7 239Pu 24110 240Pu 6561 241Am 432.2 241Pu 14.29 242Pu 375000 242mAm 141 243Am 7370 243Cm 29.1 244Pu 80000000 244Cm 18.1 245Cm 8500 246Cm 4760 247Cm 15600000 247Bk 1380 248Cm 348000 248Bk >300? 249Cf 351 250Cm 8300 250Cf 13.08 251Cf 900 252Cf 2.645 252Es 1.291
Observation:
- (Except for a few notable cases like 241) it's the more neutron-rich isotope that is more stable.
-- Limulus (talk) 09:13, 18 February 2014 (UTC)
Nuclear spin
Nuclear spin info from the respective isotope pages. "Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses."
226Ra 0+ 228Ra 0+ 227Ac 3/2- 228Th 0+ 229Th 5/2+ 230Th 0+ 232Th 0+ 231Pa 3/2- 232U 0+ 233U 5/2+ 234U 0+ 235U 7/2- 236U 0+ 238U 0+ 235Np 5/2+ 236Np (6-) 237Np 5/2+ 236Pu 0+ 238Pu 0+ 239Pu 1/2+ 240Pu 0+ 241Pu 5/2+ 242Pu 0+ 244Pu 0+ 241Am 5/2- 242mAm 5- 243Am 5/2- 243Cm 5/2+ 244Cm 0+ 245Cm 7/2+ 246Cm 0+ 247Cm 9/2- 248Cm 0+ 250Cm 0+ 247Bk (3/2-) 248Bk 6+# 249Cf 9/2- 250Cf 0+ 251Cf 1/2+ 252Cf 0+ 252Es 5-
Observation:
- All even mass number isotopes have zero spin EXCEPT Np-236, Am-242m, 248Bk and 252Es, which are the only isotopes on the list that are even from an odd number of protons plus an odd number of neutrons.
-- Limulus (talk) 22:51, 18 February 2014 (UTC)
By spin:
239Pu 1/2+ 251Cf 1/2+ 227Ac 3/2- 231Pa 3/2- 247Bk (3/2-) 229Th 5/2+ 233U 5/2+ 235Np 5/2+ 237Np 5/2+ 241Pu 5/2+ 241Am 5/2- 243Am 5/2- 243Cm 5/2+ 235U 7/2- 245Cm 7/2+ 247Cm 9/2- 249Cf 9/2- 242mAm 5- 252Es 5- 236Np (6-) 248Bk 6+#
-- Limulus (talk) 22:40, 19 February 2014 (UTC)
Observation:
- I find this very curious:
241Pu 5/2+ 241Am 5/2- 243Am 5/2- 243Cm 5/2+
Not only do the pairs have equal but opposite signs (note Pu-241 beta decays to Am-241; are the signs the result of n to p ratio? e.g. 2n3p -> 3p2n or something along those lines...) but also the two isotopes of Am (same number of protons, separated by a pair of neutrons) have the same value while Pu-241 and Cm-243 (with the same value) have the same number of neutrons (separated by a pair of protons).
-- Limulus (talk) 04:47, 20 February 2014 (UTC)
Trends
Neat! I've discovered some trends. First, the obvious one:
Iso. A Z N HL 226Ra 226 88 138 1600 232Th 232 90 142 14050000000 238U 238 92 146 4468000000 244Pu 244 94 150 80000000 250Cm 250 96 154 8300
Each of these is spaced by 2p+4n and surrounded by a 'dead zone' (if you exclude Ac-227 anyway). This is what originally got me interested in making this template. (Note: if you follow the line past radium, you'll end up at 208Pb; the LAST known stable isotope... coincidence? -- Limulus (talk) 03:00, 25 July 2014 (UTC))
Now, I also found that if you take the even-even isotopes, they're more stable with more N (up to 152) for any given Z, to the above trend line:
226Ra 226 88 138 1600 228Ra 228 88 140 5.75 228Th 228 90 138 1.9116 230Th 230 90 140 75380 232Th 232 90 142 14050000000 232U 232 92 140 68.9 234U 234 92 142 245500 236U 236 92 144 23420000 238U 238 92 146 4468000000 236Pu 236 94 142 2.858 238Pu 238 94 144 87.7 240Pu 240 94 146 6561 242Pu 242 94 148 375000 244Pu 244 94 150 80000000 244Cm 244 96 148 18.1 246Cm 246 96 150 4760 248Cm 248 96 152 348000 250Cm 250 96 154 8300 250Cf 250 98 152 13.08 252Cf 252 98 154 2.645
Then I looked at the odd-odd isotopes:
252Es 252 99 153 1.291 242mAm 242 95 147 141 248Bk 248 97 151 300 236Np 236 93 143 154000
Drop 252 (short HL, upper right) and arrange by mass:
236Np 236 93 143 154000 242mAm 242 95 147 141 248Bk 248 97 151 300
Note the trend; again spaced 2p+4n. Coincidence?!?
Finally, I looked at the odd-p/even-n and even-p/odd-n isotopes:
235Np 235 93 142 1.084 227Ac 227 89 138 21.772 241Am 241 95 146 432.2 247Bk 247 97 150 1380 243Am 243 95 148 7370 231Pa 231 91 140 32760 237Np 237 93 144 2144000 241Pu 241 94 147 14.29 243Cm 243 96 147 29.1 249Cf 249 98 151 351 251Cf 251 98 153 900 229Th 229 90 139 7340 245Cm 245 96 149 8500 239Pu 239 94 145 24110 233U 233 92 141 159200 247Cm 247 96 151 15600000 235U 235 92 143 704000000
I was hoping to see a 2p+4n pattern. But no. Nor did I see any obvious ones for 4n+1 or 4n+3 decay chains. But then I noticed this:
227Ac 227 89 138 21.772 229Th 229 90 139 7340 231Pa 231 91 140 32760 233U 233 92 141 159200 235Np 235 93 142 1.084 235U 235 92 143 704000000 237Np 237 93 144 2144000 239Pu 239 94 145 24110 241Am 241 95 146 432.2 243Cm 243 96 147 29.1 241Pu 241 94 147 14.29 243Am 243 95 148 7370 245Cm 245 96 149 8500 247Bk 247 97 150 1380 249Cf 249 98 151 351 247Cm 247 96 151 15600000 251Cf 251 98 153 900
Noting the Bk-249 discontinuity in the upper right corner, the trend is pretty straightforward along +p+n paths (which continue into the dead zone, i.e. just to the right of each of the major islands, like Th-232) that increase to a maximal value somewhere along their length and then decline.
-- Limulus (talk) 01:08, 25 July 2014 (UTC)
"Somewhere" being U (92p) or if not available, Cm (96p). -- Limulus (talk) 02:55, 25 July 2014 (UTC)
Fission and capture cross-sections
Brookhaven National Laboratory has interactive charts of nuclides:
and while they don't have fission info for all of the ones in this template, here's what they have; measured in barns:
Fission Capture 223Ra 7.002E-1 1.300E+2 226Ra 7.002E-6 1.279E+1 227Ac 2.901E-4 9.020E+2 227Th 2.020E+2 1.535E+3 228Th 3.001E-1 1.199E+2 229Th 3.164E+1 6.338E+1 233Th 1.500E+1 1.450E+3 231Pa 2.087E-2 2.006E+2 232Pa 9.780E+2 6.513E+2 232U 7.676E+1 7.519E+1 233U 5.313E+2 4.526E+1 234U 6.709E-2 1.009E+2 235U 5.850E+2 9.869E+1 236U 4.710E-2 5.133 237U 4.165E-1 4.754E+2 238U 1.679E-5 2.683 239U 1.411E+1 2.057E+1 240U 1.079E-3 1.916E+1 241U 4.165E-1 4.761E+2 235Np 2.000E+1 1.500E+2 236Np 3.011E+3 1.258E+2 237Np 2.036E-2 1.617E+2 238Np 2.070E+3 4.502E+2 236Pu 1.648E+2 3.123E+1 237Pu 2.102E+3 5.407E+2 238Pu 1.700E+1 5.608E+2 239Pu 7.479E+2 2.707E+2 240Pu 6.404E-2 2.875E+2 241Pu 1.012E+3 3.630E+2 242Pu 1.042E-3 1.916E+1 243Pu 1.814E+2 8.813E+1 241Am 3.139 6.188E+2 242Am 2.095E+3 2.190E+2 243Am 7.393E-2 7.511E+1 244Am 2.300E+3 6.001E+2 241Cm 2.600E+3 2.504E+2 242Cm 3.020 1.687E+1 243Cm 6.135E+2 1.305E+2 244Cm 1.037 1.510E+1 245Cm 2.141E+3 3.589E+2 246Cm 1.442E-1 1.311 247Cm 1.112E+2 5.692E+1 248Cm 8.736E-2 2.444 249Cm 1.025E+1 1.750 250Cm 2.089E-3 8.537E+1 249Bk 3.993 7.455E+2 250Bk 9.588E+2 3.532E+2 249Cf 1.633E+3 4.965E+2 251Cf 5.323E+3 2.862E+3 252Cf 3.217E+1 2.049E+1 253Cf 1.136E+3 3.413E+2 254Cf 2.000 4.501 254Es 1.966E+3 2.817E+1 255Es 1.343E+1 5.502E+1 255Fm 3.361E+3 2.601E+1
For those isotopes with HL >1y found in the template, AND where the ratio of fission to capture cross sections is listed by BNL, AND is 0.1 or greater:
229Th * 0.499 232U 1.021 233U * 11.739 235U * 5.928 235Np 0.133 236Np * 23.935 236Pu 5.277 239Pu * 2.763 241Pu * 2.788 243Cm * 4.701 245Cm * 5.965 246Cm 0.11 247Cm * 1.954 249Cf * 3.289 251Cf * 1.86 252Cf 1.57
NOTE: an asterisk indicates that it satisfies the fissile rule.