Question: Binary Fission Of E. Coli Time (hrs) Average Absorbance 0 0.5 1 1.5 2 2.5 3 3.5 Absorbance E. Coli Sample 1 0.1 0.092 0.111 0.143 0.186 0.341 0.49 0.659 0.92 1.151 1.344 1.386 Absorbance E. Coli Sample 2 0.093 0.092 0.098 0.133 0.204 0.312 0.464 0.65 0.97 1.174 1.345 1.393 Absorbance E. Coli Sample 3 0.095 0.094 0.1 0.135 0.206 0.314 0.466 0.652 0.972. The SightPro Fission 2.0 is a micro-compact electronic dot sight. If you're looking to minimize weight, then this 1.76 oz. Device is exactly what's needed. Perfect for use on handguns & shotguns, but also a terrific choice to mount on the side of a scope for CQ situations.
Section 12.0 Useful Tables
Nuclear Weapons Frequently Asked Questions
Version 2.03: 17 May 2006
COPYRIGHT CAREY SUBLETTE
T½ = Ln (2) /λ = 0.693 /λ. Where Ln (2) is the natural logarithm of 2 = 0.693. Examples 1: Half life. Different materials have different rates of decay and are characterised by their half lives. The half life of Uranium-238 is 4.5 billion years, roughly the age of the earth. Spontaneous fission (SF) is a form of radioactive decay that is found only in very heavy chemical elements.The nuclear binding energy of the elements reaches its maximum at an atomic mass number of about 56; spontaneous breakdown into smaller nuclei and a few isolated nuclear particles becomes possible at greater atomic mass numbers.
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Back to Main Index12.0 Useful Tables
Fissionable/Fissile Isotope Properties
Isotope | Half-Life (years) | Primary Decay Mode | Spontaneous Fission Rate - SF (F/sec/kg) | Fission Cross Section - sigma (barns, fission spectrum avg) | SF Neutron Multiplicity - nuSF (n/fission) | Fission Spectrum Neutron Multiplicity - nuFS (n/fission) | Critical Mass - Mc (kg) | Decay Heat - Q (W/kg) | Specific Activity (curies/kg) |
---|---|---|---|---|---|---|---|---|---|
Th-232 | 1.405 x 1010 | Alpha 4.083 MeV | <5 x 10-5 | 0.0785 | - | 2.16 | None | 2.654 x 10-6 | 1.097 x 10-4 |
Pa-231 | 32,760 | Alpha 5.149 MeV | <5 | 0.834 | - | 2.457 | >188 | 1.442 | 47.23 |
U-232 | 68.9 | Alpha 5.414 MeV | 2 x 10 -3 | 2.013 | 2 | 3.296 | >5 | 717.6 | 22,360 |
U-233 | 159,200 | Alpha 4.909 MeV | - | 1.946 | - | 2.649 | 16 | 0.2804 | 9.636 |
U-234 | 245,500 | Alpha 4.859 MeV | 3.9 | 1.223 | 1.8 | 2.578 | >41 | 0.1792 | 6.222 |
U-235 | 7.038 x 108 | Alpha 4.679 MeV | 5.6 x 10-3 | 1.235 | 2.0 | 2.6055 | 48 | 5.994 x 10-5 | 2.161 x 10-3 |
U-236 | 2.342 x 107 | Alpha 4.572 MeV | 2.30 | 0.594 | 1.8 | 2.526 | >167 | 1.753 x 10-3 | 0.06467 |
U-238 | 4.468 x 109 | Alpha 4.270 MeV | 5.51 | 0.308 | 1.97 +- 0.07 | 2.6010 | None | 8.508 x 10-6 | 3.361 x 10-4 |
Np-237 | 2.144 x 106 | Alpha 4.959 MeV | < 0.05 | 1.335 | 2 | 2.889 | 75-105 | 0.02068 | 0.7034 |
Pu-238 | 87.7 | Alpha 5.593 MeV | 1.204 x 106 | 1.994 | 2.28 +- 0.10 | 3.148 | 9 | 5.678 x 105 | 17,120 |
Pu-239 | 24,110 | Alpha 5.245 MeV | 10.1 | 1.800 | 2.9 | 3.1231 | 10.5 | 1.929 | 62.03 |
Pu-240 | 65,640 | Alpha 5.256 MeV | 478,000 | 1.357 | 2.189 +- 0.026 | 3.061 | 40 | 7.07 | 227 |
Pu-241 | 14.35 | Beta 0.021 MeV | <0.8 | 1.648 | - | 3.142 | 12 | 129.4 | 1.033 x 105 |
Pu-242 | 373,300 | Alpha 4.984 MeV | 805,000 | 1.127 | 2.28 +- 0.13 | 3.070 | 95, range 75-100 | 0.1169 | 3.956 |
Am-241 | 432.2 | Alpha 5.638 MeV | 500 | 1.378 | 2 | 3.457 | 83.5 | 114.7 | 3,431 |
Cf-251 | 898 | Alpha 6.176 MeV | - | 2.430 | - | 4.560 | 1.94 | 58.05 | 1,586 |
Isotope Properties and Neutron Cross Sections
This is subsection lists most isotopes of interest for direct, indirect, or theoretical nuclear weapon applications. Basic isotopes characteristics, and summary tables of significant neutron reaction cross sections are included.
The neutronic data is derived from the authoritative ENDF-VI evaluated nuclear data base compiled and maintained by the National Nuclear Data Center (NNDC) at the Brookhaven National Laboratory (BNL). The data listings below were prepared with the assistance of the Japan Atomic Energy Research Institute (JAERI).
Notes:
- The Maxwellian average cross sections are for a peak neutron energy distribution at 0.0253 eV (a room temperature thermal distribution).
- Molar volume is the minimum volume per mole for the densest phase at standard pressure and temperature (STP)
- SF = spontaneous fission
- Critical mass estimates for the fissile isotopes are given for bare spheres at the densest STP phase. Where available these estimates are from other sources and are based either on actual experimental measurement, or reasonably sophisticated numerical computations. All fissile isotopes also include for comparison critical mass estimates made by me, using an exact criticality solution with a one-group representation of neutronic properties. The one-group parameters are fission spectrum averages calculated from the ENDF-VI evaluated nuclear data base.As can be seen where outside critical mass estimates are also available, this one-group calculation method consistently underestimates the true critical mass - primarily because it does not take into account the effects of inelastic scattering in softening the neutron spectrum. The one-group calculated critical mass estimates are thus lower bounds on the true value. Comparison between the one-group calculations and the actual values for the highly fissile isotopes for which good experimental data is available (U-233, U-235, Pu-239, and Pu-241) shows a consistent underestimate of 70-75% of the true value. For less fissile isotopes, where critical mass estimates have been offered by others (these are mostly calculated estimates also, but with more sophisticated models), the underestimates are more severe (at worst 22-29% of the 'true' value for Pu-242). This too is to be expected because the effects of inelastic scattering is relatively greater in less fissile materials. On the other hand, the estimates for extremely fissile transuranics like the californium isotopes should be quite good.Sources:H. C. Paxton and N. L. Pruvost, Critical Dimensions of Systems Containing 235-U, 239-Pu, and 233-U; 1986 Rev., LA-10860-MS, Los Alamos (July 1987), p. 96-104.Hugh C. Paxton, 'Fast Critical Experiments,' Progress in Nuclear Energy Vol. 7 (1981), p. 154.Samuel Glasstone and Leslie M. Redman, An Introduction to Nuclear Weapons, WASH-1037 Revised. U.S. Atomic Energy Commission, Division of Military Applications, June 1972, pg. 12.Amory Lovins, 'Nuclear Weapons and Power-Reactor Plutonium', Nature, Vol.283, 28 Feb 1980, pp. 817-823Alexander De Volpi, Proliferation, Plutonium and Policy: Institutional and Technological Impediments to Nuclear Weapons Propagation, Pergamon (1979), pg. 86.C. C. Byers, D. E. Hansen, J. J. Koelling, E. A. Plassmann, D. R. Smith, Reactivity Coefficients of Heavy Isotopes In LASL's-Fast Critical Assemblies, LA-UR-78-427, Los Alamos (June 1978), pg. 2.Evaluation of nuclear criticality safety data and limits for actinides in transport, C4/TMR2001/200-1, IRSN (L'Institut de radioprotection et de sûreté nucléaire), 2001.Neptunium criticality achieved, http://www.lanl.gov/news/index.php?fuseaction=home.story&story_id=1348
Hydrogen
- Atomic number: 1
- Molar volume: 13.1 cm^3/mole (solid, 13 K)
- Density: 0.0763 (solid, 13 K, natural hydrogen)
- Melting point: 13.96 K (natural hydrogen)
- Boiling point: 20.39 K
1-H-1
- Atomic Mass: 1.007825032 +- 0.000000000 (amu)
- Excess Mass: 7288.969 +- 0.001 keV
- Binding Energy: 0.000 +- 0.000 keV
- Stable Isotope
- Atomic Percent Abundance: 99.985%
- >Magnetic Moment: 2.7928 nuclear magnetons
- Spin: 1/2+
Lightest possible atom, and consequently the most efficient neutron moderator. Widely used in nuclear weapon structural materials (i.e. plastics). Due to moderating ability and light weight, used to harden weapons against outside neutron fluxes (especially in combination with Li-6).
1-H-2 (Deuterium)
- Atomic Mass: 2.014101778 +- 0.000000000 (amu)
- Excess Mass: 13135.720 +- 0.001 keV
- Binding Energy: 2224.573 +- 0.002 keV
- Stable Isotope
- Atomic Percent Abundance: 0.015%
- Spin: 1+
- Magnetic Moment: 0.8574 nuclear magnetons
- Quadrupole Moment: 0.003 barns
Best nuclear reactor moderator due to high moderating efficiency and extremely low absorption cross section. A principal fusion fuel in thermonuclear weapons, can also be used for fusion boosting, and in neutron generators. Melting point 20.4 K, boiling point 23.67 K.
1-H-3 (Tritium)
- Atomic Mass: 3.016049268 +- 0.000000001 (amu)
- Excess Mass: 14949.794 +- 0.001 keV
- Binding Energy: 8481.821 +- 0.004 keV
- Beta Decay Energy: B- 18.591 +- 0.001 keV
- Half Life: 12.33 years
Specific Activity: 9613 curie/g
Radioisotopic Power: 1.059 W/g
Primary Mode of Decay: Beta to He-3- Decay Energy: B- 18.591 +- 0.001 keV
- Magnetic Moment: 2.9789 nuclear magnetons
- Spin: 1/2+
A principal thermonuclear fuel, best used in conjunction with deuterium (the D+T reaction is the easiest by far to ignite, as well as one of the most energetic). It is produced in place by tritium breeding reactions in thermonuclear weapons. It can also manufactured and loaded into weapons (with deuterium) for use in fusion boosting of fission weapons, as the neutron source in neutron bombs and neutron generators for commercial or weapons use. Tritium is a pure beta emitter. Due to weak radiation emissions, it is used in safe luminescent displays. This nuclide is useful for thickness gauge of thin plastics.
Helium
- Atomic number: 2
- Molar volume: 32.05 cm^3/mole (liquid, 4.125 K)
- Density: 0.1249 (liquid, 4.125 K, natural helium)
- Boiling point: 4.125 K
2-He-3
- Atomic Mass: 3.016029310 +- 0.000000001 (amu)
- Excess Mass: 14931.204 +- 0.001 keV
- Binding Energy: 7718.058 +- 0.002 keV
- Stable Isotope
- Atomic Percent Abundance: 0.000137%
- Magnetic Moment: -2.1276 nuclear magnetons
- Spin: 1/2+
This isotope is produced by the decay of tritium and so accumulates in fusion boosting reservoirs as an undesirable contaminant due to its high neutron absorption. It can be recycled to produce tritium by neutron bombardment. It is a valuable fusion fuel produced (and consumed) in the course of deuterium-deuterium fusion. Very rare in nature.
2-He-4
- Atomic Mass: 4.002603250 +- 0.000000001 (amu)
- Excess Mass: 2424.911 +- 0.001 keV
- Binding Energy: 28295.673 +- 0.005 keV
- Beta Decay Energy: B- -22895.261 +- 212.132 keV
- Stable Isotope
- Atomic Percent Abundance: 99.999863%
- Magnetic Moment: 0.8220 nuclear magnetons
- Quadrupole Moment: -0.001 barns
- Spin: 0+
Most common natural isotope of helium. Widely used in industry as an inert gas. Produced as an end product of fusion reactions. This isotope has a zero cross section for all neutron reactions except scattering for neutron energies below 20 MeV.
Lithium
- Atomic number: 3
- Molar volume: 13.0 cm^3/mole
- Density: 0.534
- Melting point: 180.54 C
- Boiling point: 1342 C
Fission 2 5 0 4 0
3-Li-6
- Atomic Mass: 6.015122281 +- 0.000000510 (amu)
- Excess Mass: 14086.312 +- 0.475 keV
- Binding Energy: 31994.564 +- 0.475 keV
- Beta Decay Energy: B- -4288.153 +- 5.448 keV
- Stable Isotope
- Atomic Percent Abundance: 7.42%
- Spin: 1+
- Magnetic Moment: 0.8220 nuclear magnetons
- Quadrupole Moment: -0.001 barns
Natural lithium isotope used as a thermonuclear weapon fusion fuel, in the form of lithium deuteride, due to its production of tritium through the (n,t) reaction. The very high cross section of this reaction for thermalized neutrons, combined with the light weight of the Li-6 atom, make it useful in the form of lithium hydride for hardening of nuclear weapons against external neutron fluxes.
3-Li-7
- Atomic Mass: 7.016004049 +- 0.000000507 (amu)
- Excess Mass: 14907.673 +- 0.473 keV
- Binding Energy: 39244.526 +- 0.473 keV
- Beta Decay Energy: B- -861.815 +- 0.018 keV
- Stable Isotope
- Atomic Percent Abundance: 92.58%
- Spin: 3/2-
- Magnetic Moment: 3.2564 nuclear magnetons
- Quadrupole Moment: -0.040 barns
Predominant isotope of natural lithium. Due to the large cross section for the (n,t) reaction at high neutron energies this isotope can breed substantial quantities of tritium in a fusion-driven chain reaction and thus serve as a fusion fuel. Although less efficient that Li-6 for this purpose, and not used in modern thermonuclear weapons it served this function in some early high yield weapons.
Beryllium
- Atomic number: 4
- Molar volume: 4.8775 cm^3/mole
- Density: 1.8477
- Melting point: 1287 C
- Boiling point: 2470 C
4-Be-9
- Atomic Mass: 9.012182135 +- 0.000000425 (amu)
- Excess Mass: 11347.584 +- 0.396 keV
- Binding Energy: 58164.907 +- 0.396 keV
- Beta Decay Energy: B- -1068.116 +- 0.899 keV
- Stable Isotope
- Atomic Percent Abundance: 100%
- Spin: 3/2-
Beryllium is both an excellent neutron reflector and moderator, and is in addition very light. It has one of the highest neutron scattering cross sections per unit volume, and has very low neutron absorption. Beryllium is commonly used as a neutron reflector to make compact light-weight fission weapons. Beryllium also undergoes (n,2n) neutron multiplication reactions, which are not important for fission-spectrum neutons, but may have a significant role in fusion boosted systems. Beryllium can slo generate neutrons through Be-9(gamma,n)Be-8 and Be-9(a,n)C-12 reactions. When combined with an isotope that is a strong alpha-emitter but a weak gamma-emitter (usually Po-210), Be has been used in modulated neutron initiators for fission weapons. Pu-239/Be sources have been used as convenient laboratory neutron sources; Ra-226/Be and Am-241/Be neutron sources are useful for moisture gauges.
Boron
- Atomic number: 5
- Molar volume: 4.39 cm^3/mole (alpha form, 25 C)
- Density: 2.46 (alpha form)
- Melting point: 2076 C
- Boiling point: 3900 C (estimated)
5-B-10
This natural isotope is the best absorber of fast neutrons, and an excellent absorber of slow neutrons. As a component of natural boron, it is commonly used as a neutron absorber (control rod or burnable poison) in nuclear reactors. Sonicfire pro 6 0 8. The separated isotpe has been used to harden nuclear weapons against external neutron fluxes, and to reduce the neutron preheating of fusion stages by fission triggers in thermonuclear weapons. Use of B-10 has been proposed to create 'clean' (low fallout and low neutron emission) thermonuclear weapons.
5-B-11
B-11 is the majority component of natural boron, and thus appears in boron mixtures used for nuclear applications where B-10 has not been separated.
Cobalt
- Atomic number: 27
- Molar volume: 6.61 cm^3/mole (25 C)
- Density: 8.92 (25 C)
- Melting point: 1493 C
- Boiling point: 2930 C
27-Co-59
Fission 2 5 0 42
Although the concept of the enhanced fallout 'cobalt bomb', in which radioactive Co-60 is produced by fusion neutrons, is well known this isotope is not known to have been seriously considered for weapons applications. The 5.26 year half-life of Co-60 is too long to be of real military interest, which favors more intense shorter term effects.
Tantalum
- Atomic number: 73
- Molar volume: 10.84 cm^3/mole
- Density: 16.69
- Melting point: 2996 C
- Boiling point: 5429 C
73-Ta-181
Comprising nearly all of natural tantalum, this isotope was studied for possible use in enhanced fallout radiation weapons by the U.S. in the 1950s. Compared with Co-60 the shorter half-life of Ta-182 (115 days vs 2.56 years) and the higher cross section for epithermal neutrons made Ta-181 a more desirable candidate for this use.
Thorium
- Atomic number: 90
- Molar volume: 19.80 cm^3/mole (25 C)
- Density: 11.72 (25 C)
- Melting point: 1842 C (+- 30 C)
- Boiling point: 4820 C
90-Th-232
Specific Activity: 1.097E-7 curie/g
Radioisotopic Power: 2.654E-9 W/g
Primary Mode of Decay: Alpha to Ra-228
- Decay Energy: 4.083 MeV
Secondary Mode of Decay: SF Spontaneous fission
- Branch ratio: <1.0E-9 %
- SF rate (fissions/sec/g) = <4E-6
- Neutron emission rate (N/sec/g) = <6E-6
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 1.896
- Incident neutron 1E+05 eV Nu_p = 1.910
- Incident neutron 1E+06 eV Nu_p = 2.040
- Incident neutron 4E+06 eV Nu_p = 2.472
- Incident neutron 2E+07 eV Nu_p = 4.774
- Incident neutron fission spectrum average Nu_p = 2.159
Protactinium
- Atomic number: 91
- Molar volume: 15.18 cm^3/mole (25 C)
- Density: 15.22 (Pa-231, 25 C)
- Melting point: 1568 - 1575 C
- Boiling point: unknown
91-Pa-231
- Atomic Mass: 231.0358789 +- 0.0000028 amu
- Excess Mass: 33420.973 +- 2.586 keV
- Binding Energy: 1759860.436 +- 2.605 keV
- Beta Decay Energy: B- -382.155 +- 3.220 keV
- Half Life: 32760 Y
Specific Activity: 0.04723 curie/g
Radioisotopic Power: 0.001442 W/g
Primary Mode of Decay: Alpha to Ac-227- Decay Energy: 5.149 MeV
Secondary Mode of Decay: 24NEC- Branch ratio: 13E-10 %
Tertiary Mode of Decay: Spontaneous fission- Branch ratio: <=3E-10 %
- SF rate (fissions/sec/g) = <5E-3
- Neutron emission rate (N/sec/g) = <1E-2
- Spin: 3/2-
- Critical mass: Probably not fissile (C4/TMR2001/200-1), 188 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 2.274
- Incident neutron 1E+05 eV Nu_p = 2.285
- Incident neutron 1E+06 eV Nu_p = 2.381
- Incident neutron 4E+06 eV Nu_p = 2.702
- Incident neutron 2E+07 eV Nu_p = 4.420
- Incident neutron fission spectrum average Nu_p = 2.457
Uranium
- Atomic number: 92
- Molar volume: 12.56 cm^3/mole
- Density: 18.95 (alpha form, stable to 667.8 C)
- Melting point: 1132.2 C (+/- 0.8 C)
- Boiling point: 3818 degrees C
- specific heat 6.65 cal/mole/C (25 C)
- tensile strength 450 MPa
92-U-232
- Atomic Mass: 232.037146280 +- 0.000002857 (amu)
- Excess Mass: 34601.531 +- 2.662 keV
- Binding Energy: 1765968.847 +- 2.680 keV
- Beta Decay Energy: B- -2750.000 +- 100.000 keV
- Half Life: 68.9 Y
Specific Activity: 22.36 curie/g
Radioisotopic Power: 0.7176 W/g
Primary Mode of Decay: Alpha to Th-228- Decay Energy: 5.414 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: = 2E-16 %
- SF rate (fissions/sec/g) = 2E-6
- Neutron emission rate (N/sec/g) = 4E-6
- Spin: 0+
- Critical mass: 3.57-3.70 kg (C4/TMR2001/200-1), 5.04 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E+00 eV Nu_p = 3.126
- Incident neutron 1E+05 eV Nu_p = 3.136
- Incident neutron 1E+06 eV Nu_p = 3.233
- Incident neutron 4E+06 eV Nu_p = 3.554
- Incident neutron 1.5E+07 eV Nu_p = 4.732
- Incident neutron fission spectrum average Nu_p = 3.296
92-U-233
- Atomic Mass: 233.039628196 +- 0.000003010 (amu)
- Excess Mass: 36913.421 +- 2.804 keV
- Binding Energy: 1771728.280 +- 2.821 keV
- Beta Decay Energy: B- -1028.513 +- 51.640 keV
- Half Life: 159200 Y
Specific Activity: 0.009636 curie/g
Radioisotopic Power: 0.0002804 W/g
Primary Mode of Decay: Alpha to Th-229- Decay Energy: 4.909 MeV
- Spin: 5/2+
- Critical mass: 16 kg (LA-10860-MS; De Volpi; Hugh C. Paxton 1981), 11.63 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 2.53E-05 eV Nu_p = 2.487
- Incident neutron 1E+05 eV Nu_p = 2.487
- Incident neutron 1E+06 eV Nu_p = 2.565
- Incident neutron 2E+06 eV Nu_p = 2.680
- Incident neutron 1.4E+07 eV Nu_p = 4.223
- Incident neutron fission spectrum average Nu_p = 2.649
92-U-234
- Atomic Mass: 234.040945606 +- 0.000002122 (amu)
- Excess Mass: 38140.580 +- 1.976 keV
- Binding Energy: 1778572.444 +- 2.002 keV
- Beta Decay Energy: B- -1809.846 +- 8.321 keV
- Atomic Percent Abundance: 0.0055%
- Half Life: 245500 Y
Specific Activity: 0.006222 curie/g
Radioisotopic Power: 0.0001792 W/g
Primary Mode of Decay: Alpha to Th-230- Decay Energy: 4.859 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 1.7E-9 %
- SF rate (fissions/sec/g) = 3.9E-3
- Neutron emission rate (N/sec/g) = 7.2E-3
- Spin: 0+
- Critical mass: 145-149 kg (C4/TMR2001/200-1), 40.6 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E+00 eV Nu_p = 2.339
- Incident neutron 1E+05 eV Nu_p = 2.353
- Incident neutron 1E+06 eV Nu_p = 2.474
- Incident neutron 4E+06 eV Nu_p = 2.879
- Incident neutron 1.5E+07 eV Nu_p = 4.369
- Incident neutron fission spectrum average Nu_p = 2.578
92-U-235
- Atomic Mass: 235.043923062 +- 0.000002115 (amu)
- Excess Mass: 40914.062 +- 1.970 keV
- Binding Energy: 1783870.285 +- 1.996 keV
- Beta Decay Energy: B- -123.716 +- 0.869 keV
- Atomic Percent Abundance: 0.720%
- Spin: 7/2- 7
- Half Life: 7.038E8 Y
Specific Activity: 2.161E-6 curie/g
Radioisotopic Power: 5.994E-8 W/g
Primary Mode of Decay: Alpha to Th-231- Decay Energy: 4.679 MeV
Primary Mode of Decay: Spontaneous fission- Branch ratio: 7.0E-9%
- SF rate (fissions/sec/g) = 5.6E-6
- Neutron emission rate (N/sec/g) = 1.1E-5
- Meta state at 0.000 Mev
Half Life: ~25 M
Primary Mode of Decay: IT to U-235 - Spin: 1/2+
- Critical mass: 48 kg (LA-10860-MS; De Volpi), 33.4 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 2.53E-05 eV Nu_p = 2.4200
- Incident neutron 1E+05 eV Nu_p = 2.4158
- Incident neutron 1E+06 eV Nu_p = 2.5150
- Incident neutron 2E+06 eV Nu_p = 2.6303
- Incident neutron 4E+06 eV Nu_p = 2.8749
- Incident neutron 1.4E+07 eV Nu_p = 4.3857
- Incident neutron fission spectrum average Nu_p = 2.6055
92-U-236
- Atomic Mass: 236.045561897 +- 0.000002091 (amu)
- Excess Mass: 42440.627 +- 1.948 keV
- Binding Energy: 1790415.042 +- 1.974 keV
- Beta Decay Energy: B- -929.469 +- 50.427 keV
- Spin: 0+
- Half Life: 2.342E7 Y
Specific Activity: 6.467E-5 curie/g
Radioisotopic Power: 1.753E-6 W/g
Primary Mode of Decay: Alpha to Th-232- Decay Energy: 4.572 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 9.6E-8 %
- SF rate (fissions/sec/g) = 0.00230
- Neutron emission rate (N/sec/g) = 0.0041
- Critical mass: Not fissile (C4/TMR2001/200-1), 167 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-03 eV Nu_p = 2.294
- Incident neutron 1E+05 eV Nu_p = 2.307
- Incident neutron 1E+06 eV Nu_p = 2.425
- Incident neutron 4E+06 eV Nu_p = 2.818
- Incident neutron 1.5E+07 eV Nu_p = 4.267
- Incident neutron fission spectrum average Nu_p = 2.526
92-Uranium-238
- Atomic Mass: 238.050782583 +- 0.000002126 (amu)
- Excess Mass: 47303.664 +- 1.980 keV
- Binding Energy: 1801694.651 +- 2.006 keV
- Beta Decay Energy: B- -147.065 +- 1.145 keV
- Atomic Percent Abundance: 99.2745%
- Half Life: 4.468E+9 Y
Specific Activity: 3.361E-7 curie/g
Radioisotopic Power: 8.508E^-9 W/g
Primary Mode of Decay: Alpha to Th-234- Decay Energy: 4.270 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 0.000044 %
- Average neutron yield (Nu)
Nu_prompt = 1.97 +- 0.07 - SF rate (fissions/sec/g) = 0.00551
- Neutron emission rate (N/sec/g) = 0.0108
- Spin: 0+
- Critical mass: none (not fissile)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 2.53000E-02 eV Nu_p = 2.4481
- Incident neutron 1E+05 eV Nu_p = 2.4552
- Incident neutron 1E+06 eV Nu_p = 2.5194
- Incident neutron 2.9E+06 eV Nu_p = 2.6548
- Incident neutron 5.15E+06 eV Nu_p = 3.0840
- Incident neutron 2E+07 eV Nu_p = 5.1819
- Incident neutron fission spectrum average Nu_p = 2.6010
Neptunium
- Atomic number: 93
- Molar volume: 11.59 cm^3/mole (25 C)
- Density: 20.45 (Np-237, 25 C)
- Melting point: 637 C
- Boiling point: 4000 C
93-Np-237
- Atomic Mass: 237.0481673 +- 0.0000021 amu
- Excess Mass: 44867.501 +- 1.961 keV
- Binding Energy: 1795277.138 +- 1.986 keV
- Beta Decay Energy: B- -220.318 +- 1.298 keV
- Half Life: 2.144E6 Y
Specific Activity: 7.034E-4 curie/g
Radioisotopic Power: 2.068E^-5 W/g
Primary Mode of Decay: Alpha to Pa-233- Decay Energy: 4.959 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: <=2E-10 %
- SF rate (fissions/sec/g) = < 5.E-5
- Neutron emission rate (N/sec/g) = < 1.E-4
- Spin: 5/2+
- Critical mass: 60 kg (Neptunium criticality achieved), 63.6-81.9 kg (C4/TMR2001/200-1), 18.5 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 2.625
- Incident neutron 1E+05 eV Nu_p = 2.640
- Incident neutron 1E+06 eV Nu_p = 2.775
- Incident neutron 4E+06 eV Nu_p = 3.224
- Incident neutron 2E+07 eV Nu_p = 5.521
- Incident neutron fission spectrum average Nu_p = 2.889
Plutonium
- Atomic number: 94
- Molar volume: 12.061 cm^3/mole
- Density: 19.816 (20 C)
- Melting point: 639.5
- Boiling point: 3230 C
94-Pu-238
- Atomic Mass: 238.0495534 +- 0.0000021 amu
- Excess Mass: 46158.688 +- 1.982 keV
- Binding Energy: 1801274.921 +- 2.008 keV
- Beta Decay Energy: B- -2258.350 +- 50.688 keV
- Half Life: 87.7 Y
Specific Activity: 17.12 curie/g
Radioisotopic Power: 0.5678 W/g
Primary Mode of Decay: Alpha to U-234
Secondary Mode of Decay: Spontaneous fission
- Branch ratio: 1.9E-7 %
- Average neutron yield (Nu)
Nu_prompt = 2.28 +- 0.10 - SF rate (fissions/sec/g) = 1204.
- Neutron emission rate (N/sec/g) = 2745.
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 2.891
- Incident neutron 1E+05 eV Nu_p = 2.906
- Incident neutron 1E+06 eV Nu_p = 3.039
- Incident neutron 4E+06 eV Nu_p = 3.483
- Incident neutron 1.4E+07 eV Nu_p = 4.964
- Incident neutron fission spectrum average Nu_p = 3.148
94-Pu-239
- Atomic Mass: 239.0521565 +- 0.0000021 amu
- Excess Mass: 48583.478 +- 1.971 keV
- Binding Energy: 1806921.454 +- 1.998 keV
- Beta Decay Energy: B- -802.912 +- 2.011 keV
- Half Life: 24110 Y
Specific Activity: 0.06203 curie/g
Radioisotopic Power: 0.001929 W/g
Primary Mode of Decay: Alpha to U-235- Decay Energy: 5.245 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 3E-10 %
- Average neutron yield (Nu)
Nu_prompt = - SF rate (fissions/sec/g) = 7.E-3
- Neutron emission rate (N/sec/g) = 2.E-2
- Spin: 1/2+
- Critical mass: 10.5 kg (LA-10860-MS, WASH-1037 Rev., p. 12), 10.0-10.3 kg (C4/TMR2001/200-1), 7.42 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 2.53E-02 eV Nu_p = 2.8725
- Incident neutron 1E+05 eV Nu_p = 2.8976
- Incident neutron 1E+06 eV Nu_p = 3.0107
- Incident neutron 4E+06 eV Nu_p = 3.4456
- Incident neutron 1.4E+07 eV Nu_p = 4.9397
- Incident neutron fission spectrum average Nu_p = 3.1231
94-Pu-240
- Atomic Mass: 240.0538075 +- 0.0000021 amu
- Excess Mass: 50121.319 +- 1.947 keV
- Binding Energy: 1813454.935 +- 1.974 keV
- Beta Decay Energy: B- -1378.952 +- 13.790 keV
- Half Life: 6564 Y
Specific Activity: 0.227 curie/g
Radioisotopic Power: 0.00707 W/g
Primary Mode of Decay: Alpha to U-236- Decay Energy: 5.256 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 5.7E-6 %
- Average neutron yield (Nu)
Nu_prompt = 2.189 +- 0.026 - SF rate (fissions/sec/g) = 478.
- Neutron emission rate (N/sec/g) = 1047.
- Spin: 0+
- Critical mass: 35.7 kg (C4/TMR2001/200-1), 40 kg (Lovins; De Volpi), 15.2 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 2.794
- Incident neutron 4E+06 eV Nu_p = 3.402
- Incident neutron 1.4E+07 eV Nu_p = 4.922
- Incident neutron fission spectrum average Nu_p = 3.061
94-Pu-241
- Atomic Mass: 241.0568453 +- 0.0000021 amu
- Excess Mass: 52951.039 +- 1.948 keV
- Binding Energy: 1818696.538 +- 1.975 keV
- Beta Decay Energy: B- 20.815 +- 0.199 keV
- Spin: 5/2+
- Half Life: 14.35 Y
Specific Activity: 103.3 curie/g
Radioisotopic Power: 0.01287 W/g
Primary Mode of Decay: Beta to Am-241- Decay Energy: 0.021 MeV
Secondary Mode of Decay: Alpha to U-237- Branch ratio: 0.0025 %
- Decay Energy: 5.140 MeV
Tertiary Mode of Decay: Spontaneous fission- Branch ratio: <2.E-14 %
- SF rate (fissions/sec/g) = <8.E-4
- Spin: 5/2+
- Critical mass: 12.3-13.0 kg (C4/TMR2001/200-1), 12 kg (Lovins; De Volpi), 9.03 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 2.930
- Incident neutron 1E+05 eV Nu_p = 2.930
- Incident neutron 1E+06 eV Nu_p = 3.013
- Incident neutron 4E+06 eV Nu_p = 3.490
- Incident neutron 2E+07 eV Nu_p = 5.963
- Incident neutron fission spectrum average Nu_p = 3.142
94-Pu-242
- Atomic Mass: 242.0587368 +- 0.0000021 amu
- Excess Mass: 54713.012 +- 1.966 keV
- Binding Energy: 1825005.887 +- 1.993 keV
- Beta Decay Energy: B- -750.963 +- 0.718 keV
- Half Life: 3.733E5 Y
Specific Activity: 0.003956 curie/g
Radioisotopic Power: 0.0001169 W/g
Primary Mode of Decay: Alpha to U-238- Decay Energy: 4.984 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 0.00055 %
- Average neutron yield (Nu)
Nu_prompt = 2.28 +- 0.13 - SF rate (fissions/sec/g) = 805.
- Neutron emission rate (N/sec/g) = 1840
- Spin: 0+
- Critical mass: 85.6 kg (C4/TMR2001/200-1), 90 kg (LA-UR-78-427), 95 kg (Lovins), range 75-100 kg (De Volpi); 22.1 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 2.790
- Incident neutron 1E+05 eV Nu_p = 2.806
- Incident neutron 1E+06 eV Nu_p = 2.948
- Incident neutron 4E+06 eV Nu_p = 3.421
- Incident neutron 2E+07 eV Nu_p = 5.950
- Incident neutron fission spectrum average Nu_p = 3.070
Americium
- Atomic number: 95
- Molar volume: 17.63 cm^3/mole
- Density: 13.67 (Am-241, 25 C)
- Melting point: 1175 C
- Boiling point: 2607 C
95-Am-241
- Atomic Mass: 241.0568229 +- 0.0000021 amu
- Excess Mass: 52930.224 +- 1.957 keV
- Binding Energy: 1817935.000 +- 1.984 keV
- Beta Decay Energy: B- -767.357 +- 1.173 keV
- Half Life: 432.2 Y
Specific Activity: 3.431 curie/g
Radioisotopic Power: 0.1147 W/g
Primary Mode of Decay: Alpha to Np-237- Decay Energy: 5.638 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 4E-10 %
- SF rate (fissions/sec/g) = 0.5
- Neutron emission rate (N/sec/g) = 1.
- Spin: 5/2-
- Critical mass: 58 kg (LA-UR-78-427), 57.6-75.6 kg (C4/TMR2001/200-1), 83.5 kg (Lovins; density adjusted), 23 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 3.235
- Incident neutron 2E+05 eV Nu_p = 3.262
- Incident neutron 1E+06 eV Nu_p = 3.369
- Incident neutron 4E+06 eV Nu_p = 3.769
- Incident neutron 1.4E+07 eV Nu_p = 5.057
- Incident neutron fission spectrum average Nu_p = 3.457
![Fission Fission](https://d1e4pidl3fu268.cloudfront.net/3ad1d747-bc20-4d93-96db-3395b9c9e991/coverslide.crop_974x731_2%2C0.preview.png)
95-Am-243
- Atomic Mass: 243.0613727 +- 0.0000023 amu
- Excess Mass: 57168.280 +- 2.178 keV
- Binding Energy: 1829839.589 +- 2.203 keV
- Beta Decay Energy: B- -8.908 +- 1.434 keV
- Half Life: 7370 Y
Specific Activity: 0.1996 curie/g
Radioisotopic Power: 0.006433 W/g
Primary Mode of Decay: Alpha to Np-239- Decay Energy: 5.438 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 3.7E-9 %
- SF rate (fissions/sec/g) = 0.27
- Neutron emission rate (N/sec/g) = 0.76
- Spin: 5/2-
- Critical mass: 209 kg (C4/TMR2001/200-1), 38.1 kg (one-group calculation, assuming the same ratio between one-group and multi-group values as Am-241 a 'true' value of 140 kg can be estimated)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 3.265
- Incident neutron 2E+05 eV Nu_p = 3.292
- Incident neutron 1E+06 eV Nu_p = 3.403
- Incident neutron 4E+06 eV Nu_p = 3.812
- Incident neutron 1.4E+07 eV Nu_p = 5.129
- Incident neutron fission spectrum average Nu_p = 3.496
Californium
- Atomic number: 98
- Molar volume: 16.5 cm^3/mole
- Density: 15.1 (Cf-249, 25 C)
- Melting point: 900 C (+- 30 C)
- Boiling point:
98-Cf-249
Specific Activity: 4.089 curie/g
Radioisotopic Power: 0.1526 W/g
Primary Mode of Decay: Alpha to Cm-245
- Decay Energy: 6.295 MeV
Secondary Mode of Decay: Spontaneous fission
- Branch ratio: 5.2E-7 %
- SF rate (fissions/sec/g) = 787
- Neutron emission rate (N/sec/g) = 2800
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 3.884
- Incident neutron 1E+05 eV Nu_p = 3.902
- Incident neutron 1E+06 eV Nu_p = 4.061
- Incident neutron 4E+06 eV Nu_p = 4.701
- Incident neutron 1.1E+07 eV Nu_p = 5.880
- Incident neutron fission spectrum average Nu_p = 4.221
98-Cf-251
- Atomic Mass: 251.0795801 +- 0.0000049 amu
- Excess Mass: 74128.333 +- 4.545 keV
- Binding Energy: 1875103.058 +- 4.558 keV
- Beta Decay Energy: B- -375.892 +- 7.107 keV
- Half Life: 898 Y
Specific Activity: 1.586 curie/g
Radioisotopic Power: 0.05805 W/g
Primary Mode of Decay: Alpha to Cm-247- Decay Energy: 6.176 MeV
- Spin: 1/2+
- Critical mass: 5.46 kg (C4/TMR2001/200-1), 1.94 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 4.133
- Incident neutron 1E+05 eV Nu_p = 4.157
- Incident neutron 1E+06 eV Nu_p = 4.374
- Incident neutron 4E+06 eV Nu_p = 5.097
- Incident neutron 1.15E+07 eV Nu_p = 6.917
- Incident neutron fission spectrum average Nu_p = 4.560
98-Cf-252
- Atomic Mass: 252.0816196 +- 0.0000055 amu
- Excess Mass: 76028.139 +- 5.095 keV
- Binding Energy: 1881274.575 +- 5.106 keV
- Beta Decay Energy: B- -1260.000 +- 50.000 keV
- Half Life: 2.645 Y
Specific Activity: 536.2 curie/g
Radioisotopic Power: 38.8 W/g (about half fission, half alpha decay)
Primary Mode of Decay: Alpha to Cm-248- Branch ratio: 96.91%
- Decay Energy: 6.217 MeV
Secondary Mode of Decay: Spontaneous fission- Branch ratio: 3.09%
- Average neutron yield (Nu)
Nu_prompt = 3.7590 +- 0.0048
Nu_delayed = 0.0086 +- 0.0010
Nu_total = 3.7676 +- 0.004 - SF rate (fissions/sec/g) = 6.13E11
- Neutron emission rate (N/sec/g) = 2.31E12
- Spin: 0+
- Critical mass: 5.87-7.93 kg (C4/TMR2001/200-1), 2.73 kg (one-group calculation)
Average neutron induced Nu_p (prompt neutrons/fission)
- Incident neutron 1E-05 eV Nu_p = 4.060
- Incident neutron 1E+05 eV Nu_p = 4.087
- Incident neutron 1E+06 eV Nu_p = 4.325
- Incident neutron 4E+06 eV Nu_p = 5.119
- Incident neutron 1.5E+07 eV Nu_p = 7.961
- Incident neutron fission spectrum average Nu_p = 4.374