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)


 * (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:

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:
 * Thermal neutron capture cross sections σ(n,γ)
 * Thermal neutron fission cross sections σ(n,F)

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.

-- Limulus (talk) 07:50, 20 December 2014 (UTC)