5203:
293:
5191:
390:
produced by fission reactions, beryllium emits neutrons. With a 10-centimeter (4 in) beryllium reflector, the critical mass of highly enriched uranium is 14.1 kg, compared with 52.5 kg in an untamped sphere. A beryllium tamper also minimizes the loss of X-rays, which is important for a thermonuclear primary which uses its X-rays to compress the secondary stage.
2364:
3515:
405:
How shot on 5 June 1952, and since then beryllium has been widely used as a tamper in thermonuclear primaries. The secondary's tamper (or "pusher") functions to reflect neutrons, confine the fusion fuel with its inertial mass, and enhance the yield with its fissions produced by neutrons emitted from
235:
Serber noted that the neutron reflection property was not as good as it might first seem, because the neutrons returning from collisions in the tamper would take time to do so. He estimated that for a uranium tamper they might take about 10 seconds. By the time reflected neutrons return to the core,
265:
tamper. This was important not just for neutron reflection but also for its strength in preventing the projectile from blowing through the target. The tamper had a radius of 17.5 centimetres (6.9 in) and a thickness of 11.3 centimetres (4.4 in), for a mass of 317 kilograms (699 lb).
389:
tamper. In a boosted device the thermonuclear reactions greatly increase the production of neutrons, which makes the inertial property of tampers less important. Beryllium has a low slow neutron absorbency cross section but a very high scattering cross section. When struck by high energy neutrons
376:
reaction can remain sufficiently energetic to fission uranium-238 even after three collisions with deuterium, but the 2.45-megaelectronvolt (0.393 pJ) ones produced by deuterium-deuterium fusion no longer have sufficient energy after even a single collision. A uranium-235 tamper will fission
3791:
680:
2568:
4211:
430:, but a low cross-section for the absorption of the fast neutrons that fission uranium-238. It was used in thermonuclear weapons to protect the plutonium spark plug from stray neutrons emitted by the uranium-238 tamper. In the Fat Man type the natural uranium tamper was coated with
974:
2141:
3245:
417:
can also be used as a fissionable tamper. It has an atomic weight nearly as high as uranium and a lower propensity to fission, which means that the tamper has to be much thicker. It is possible that a state seeking to develop nuclear weapons capability might add
4330:
In this case, the critical radius is twice what it would be if no tamper were present. Since the volume is proportional to the cube of the radius, we reach Serber's conclusion that an eightfold reduction in the critical mass is theoretically possible.
1338:
1446:
381:
tamper is therefore more efficient than a depleted uranium one, and a smaller tamper can be used to achieve the same yield. The use of enriched uranium tampers therefore became more common once enriched uranium became more plentiful.
3135:
1948:
3911:
3579:
524:
245:
was required to get the same energy release with a gold tamper compared to a uranium one, despite the fact that the critical masses differed by 50%. At the time, the critical masses of uranium (and more particularly
2375:
4002:
117:
and by delaying the expansion of the bomb, the effect on the critical mass is not as great. The reason for this is that the process of reflection is time-consuming. By the time reflected neutrons return to the
332:
striking a uranium-238 nucleus is eight times as likely to be inelastically scattered as to produce a fission, and when it does so, it is slowed to the point below the fission threshold of uranium-238. In the
4325:
1140:
3991:
240:
would have passed, meaning the contribution from the older generation is a tiny fraction of the neutron population. The returning neutrons would also be slowed by the collision. It followed that 15% more
870:
168:
delays the expansion of the reacting material. For this reason such an envelope is often called a tamper. Use of a tamper clearly makes for a longer lasting, more energetic and more efficient explosion.
2104:
1838:
2359:{\displaystyle \lambda _{t}^{core}{{\Bigl (}{\frac {\partial N_{core}}{\partial r}}{\Bigr )}}_{R_{core}}=\lambda _{t}^{tamper}{\Bigl (}{\frac {\partial N_{tamper}}{\partial r}}{\Bigr )}_{R_{core}}}
479:. It therefore produces short-lived but intense radiation, which may have battlefield uses, although this was not its purpose in the W71. Another element evaluated by the US for such a purpose was
3237:
3510:{\displaystyle {\Bigl (}{\frac {R_{tamper}^{threshold}}{d_{core}}}{\Bigr )}cot{\Bigl (}{\frac {R_{tamper}^{threshold}}{d_{core}}}{\Bigr )}=1-{\frac {\lambda _{t}^{tamper}}{\lambda _{t}^{core}}}}
1208:
393:
The beryllium tamper had been considered by the
Manhattan Project, but beryllium was in short supply, and experiments with a beryllium tamper did not commence until after the war. Physicist
471:
had a gold tamper around its secondary to maximize its output of X-rays, which it used to incapacitate incoming nuclear warheads. The irradiation of gold-197 produces gold-198, which has a
3571:
1567:
67:. The weapon disintegrates as the reaction proceeds, and this stops the reaction, so the use of a tamper makes for a longer-lasting, more energetic and more efficient explosion. The
232:
of a nuclear weapon with a tamper would be one-eighth that of an identical but untamped weapon. He added that in practice this would only be about a quarter instead of an eighth.
836:
791:
2603:
2133:
1477:
1643:
1219:
1349:
1503:
483:. Natural tantalum is almost entirely tantalum-181, which when irradiated with neutrons become tantalum-182, a beta and gamma ray emitter with a half-life of 115 days.
1987:
406:
the thermonuclear reactions. It also helps drive the radiation implosion and prevent the loss of thermal energy. For this reason, the heavy tamper is still preferred.
730:
750:
5128:
Semkow, Thomas M.; Parekh, Pravin P.; Haines, Douglas K. (28 August – 1 September 2005). "Modeling the
Effects of the Trinity Test". In Semkow, Thomas M. (ed.).
1610:
1590:
858:
703:
2611:
5161:
Atomic Energy for
Military Purposes: The Official Report on the Development of the Atomic Bomb under the Auspices of the United States Government, 1940–1945
1849:
422:
to a natural uranium tamper. This would cause problems with neutron emissions from the plutonium, but it might be possible to overcome this with a layer of
3802:
63:, which delays the thermal expansion of the fissioning fuel mass, keeping it supercritical longer. Often the same layer serves both as tamper and as
3786:{\displaystyle {\Bigl (}{\frac {R_{tamper}^{threshold}}{d_{core}}}{\Bigr )}cot{\Bigl (}{\frac {R_{tamper}^{threshold}}{d_{core}}}{\Bigr )}=-\infty }
1953:
Serber noted that at the boundary between the core and the tamper, the diffusion stream of neutrons must be continuous, so if the core has radius
980:
675:{\displaystyle {\frac {\partial N}{\partial t}}={\frac {v_{n}}{\lambda _{f}^{core}}}(\nu -1)N+{\frac {\lambda _{t}^{core}v_{n}}{3}}(\nabla ^{2}N)}
2563:{\displaystyle N_{tamper}(R_{tamper})=-{\frac {2}{3}}\lambda _{t}^{tamper}{\Bigl (}{\frac {\partial N_{tamper}}{\partial r}}{\Bigr )}_{R_{core}}}
250:) were not precisely known. It was thought that uranium with a uranium tamper might be about 25 kg, while that of plutonium would be about 5 kg.
5202:
5169:
5137:
5021:
4898:
4860:
4830:
4800:
4740:
4206:{\displaystyle {\Bigl (}{\frac {R_{tamper}^{threshold}}{d_{core}}}{\Bigr )}cot{\Bigl (}{\frac {R_{tamper}^{threshold}}{d_{core}}}{\Bigr )}=0}
102:, allowing the primary's energy output to escape quickly to be used in compressing the secondary stage. More exotic tamper materials such as
136:
4222:
503:
502:
when irradiated with neutrons. With a half-life of 5.26 years, this could produce long-lasting radioactive contamination. The
British
989:
969:{\displaystyle \nabla ^{2}N={\frac {1}{r^{2}}}{\frac {\partial }{\partial r}}{\bigl (}r^{2}{\frac {\partial N}{\partial r}}{\bigr )}}
5096:
4770:
3922:
5132:. 230th American Chemical Society (ACS) national meeting. ACS Symposium Series. Vol. 945. Washington, D.C. pp. 142–159.
266:
This was about 3.5 times the mass of the fissile material used. Tungsten carbide has a high density and a low neutron absorbency
4730:
510:
used cobalt pellets as a "tracer" for determining yield. This fuelled rumours that
Britain had been developing a cobalt bomb.
5223:
1995:
1651:
278:
of about 675 per kg per second; a 300 kg depleted uranium tamper would therefore have an unacceptable chance of initiating a
402:
353:
tamper. An estimated 14.5 tonnes of TNT (61 GJ) of the 21 kilotonnes of TNT (88 TJ) yield was contributed by the
224:-reflecting properties, although he cautioned that a great deal more work needed to be done in this area. Using elementary
3143:
1343:
For the tamper, the first term in the first equation relating to the production of neutrons can be disregarded, leaving:
449:
alloy. Bismuth has the highest atomic number of any non-fissionable tamper material. The use of lead and bismuth reduces
258:
1151:
475:
of 2.697 days and emits 0.412-megaelectronvolt (0.0660 pJ) gamma rays and 0.96-megaelectronvolt (0.154 pJ)
5181:
3523:
279:
5195:
4855:. Swords of Armageddon: US Nuclear Weapons Development since 1945. Sunnyvale, California: Chukelea Publications.
4825:. Swords of Armageddon: US Nuclear Weapons Development since 1945. Sunnyvale, California: Chukelea Publications.
4795:. Swords of Armageddon: US Nuclear Weapons Development since 1945. Sunnyvale, California: Chukelea Publications.
1511:
1613:
426:, which has a high neutron cross section for the absorption of the slow neutrons that fission uranium-235 and
126:
have passed, meaning the contribution from the older generation is a tiny fraction of the neutron population.
438:
419:
286:
33:
437:
Non-fissionable materials can be used as tampers. Sometimes these were substituted for fissionable ones in
468:
361:
338:
237:
123:
3520:
If the tamper (unrealistically) is a vacuum, then the neutron scattering cross section would be zero and
800:
755:
267:
145:
52:
2576:
5052:
4984:
4929:
4644:
2112:
1333:{\displaystyle d_{core}={\sqrt {\frac {\lambda _{f}^{core}\lambda _{t}^{core}}{3(-\alpha +\nu -1)}}}}
398:
365:
346:
341:
and at
Nagasaki, the tamper consisted of 7.0-centimetre (2.75 in) shells of natural uranium and
179:
119:
87:
68:
1441:{\displaystyle {\frac {\partial N}{\partial t}}={\frac {\lambda _{t}^{core}v_{n}}{3}}(\nabla ^{2}N)}
1454:
329:
275:
1622:
5155:
4882:
141:
1482:
86:
implosion system and makes the entire device larger and heavier. The primary stage of a modern
5165:
5143:
5133:
5118:
5102:
5092:
5070:
5027:
5017:
5000:
4963:
4945:
4904:
4894:
4866:
4856:
4836:
4826:
4806:
4796:
4776:
4766:
4746:
4736:
4482:
1956:
441:
where a high yield was unnecessary. The most commonly used non-fissionable tamper material is
197:
192:
149:
106:
are used for special purposes like emitting large amounts of X-rays or altering the amount of
64:
498:
at 9.9 kiloelectronvolts (1.59 fJ). Natural cobalt is entirely cobalt-59, which becomes
5060:
4992:
4953:
4937:
4889:
Critical
Assembly: A Technical History of Los Alamos During the Oppenheimer Years, 1943–1945
4878:
4478:
861:
378:
271:
262:
242:
225:
79:
48:
3916:
If the tamper is very thick and has neutron scattering properties similar to the core, ie:
708:
735:
454:
450:
350:
153:
107:
75:
5056:
4988:
4933:
4648:. Vol. CLXXIII, no. 25, 813. Tasmania, Australia. 10 September 1953. p. 1
2369:
Otherwise each side would have to be multiplied by the relevant neutron velocity. Also:
17:
5207:
5082:
4958:
4917:
4887:
3130:{\displaystyle {\Bigl }{\Bigl }+{\frac {\lambda _{t}^{tamper}}{\lambda _{t}^{core}}}=0}
1595:
1575:
843:
794:
688:
465:
183:
40:
1943:{\displaystyle d_{tamper}={\sqrt {\frac {\lambda _{f}^{core}\lambda _{t}^{core}}{3}}}}
5217:
5114:
5086:
4557:
476:
427:
229:
187:
161:
56:
5159:
4848:
4818:
4788:
4758:
4726:
1505:(meaning that the neutron density in the tamper is constant) the solution becomes:
394:
354:
317:
292:
1645:(meaning that the neutron density in the tamper is growing) the solution becomes:
518:
The diffusion equation for the number of neutrons within a bomb core is given by:
3906:{\displaystyle {\Bigl (}{\frac {R_{tamper}^{threshold}}{d_{core}}}{\Bigr )}=\pi }
487:
325:
313:
305:
283:
4975:
Reed, B. Cameron (August 2009). "A Brief Primer on Tamped
Fission-Bomb Cores".
4941:
401:
involving one. A device with a beryllium tamper was successfully tested in the
5031:
4374:
4372:
445:, which is both widely available and cheap. British designs often used a lead-
254:
99:
5147:
5074:
5004:
4949:
4870:
4840:
4810:
4780:
4639:
270:. Despite being available in adequate quantity during the Manhattan Project,
5106:
4908:
4750:
507:
499:
472:
386:
369:
342:
301:
247:
91:
83:
4967:
113:
While the effect of a tamper is to increase efficiency, both by reflecting
312:
There are advantages to using a fissionable tamper to increase the yield.
480:
423:
213:
446:
414:
373:
334:
221:
217:
209:
201:
165:
114:
60:
5065:
5040:
4996:
4732:
Britain, Australia and the Bomb: The
Nuclear Tests and Their Aftermath
204:
was the key, the densest materials were preferable, and he identified
2109:
If the neutron velocity in the core and the tamper is the same, then
495:
491:
164:
of the bomb, but here the envelope has an additional role: its very
5016:(second ed.). Hedelberg Dordrecht London New York: Springer.
431:
368:, the 14.1-megaelectronvolt (2.26 pJ) neutrons produced by a
321:
291:
95:
4320:{\displaystyle {\frac {R_{tamper}^{threshold}}{d_{core}}}=\pi /2}
494:
is poor prospect for a tamper because it is relatively light and
860:
doesn't depend on the direction, so we can use this form of the
453:, as neither produces isotopes that emit significant amounts of
442:
385:
An important development after World War II was the lightweight
205:
103:
59:
and to delay the expansion of the reacting material through its
1135:{\displaystyle N_{core}(r,t)=N_{0}e^{(\alpha /\tau )t}{\Bigl }}
4378:
461:
297:
4526:
4524:
3986:{\displaystyle \lambda _{t}^{tamper}\sim \lambda _{t}^{core}}
200:, which built the first nuclear weapons. He noted that since
752:
is the number of secondary neutrons produced per fission,
324:), and about half the neutrons produced by the fission of
196:, a series of lectures given in April 1943 as part of the
4551:
4549:
4547:
4545:
4543:
4541:
4539:
4918:"Estimating the Photo-Fission Yield of the Trinity Test"
4359:
4357:
4355:
2099:{\displaystyle N_{core}(R_{core})=N_{tamper}(R_{core})}
1833:{\displaystyle N_{tamper}=e^{(\delta /\tau )t}{\Bigl }}
220:
as the best candidates. He believed they also had good
47:
is an optional layer of dense material surrounding the
4693:
4691:
4689:
4687:
838:
is transport mean free path for neutrons in the core.
274:
was not used because it has a relatively high rate of
5179:
4225:
4005:
3925:
3805:
3582:
3526:
3248:
3146:
2614:
2579:
2378:
2144:
2115:
1998:
1959:
1852:
1654:
1625:
1598:
1578:
1514:
1485:
1457:
1352:
1222:
1154:
992:
873:
846:
803:
758:
738:
711:
691:
527:
5130:
Applied
Modeling and Computations in Nuclear Science
4401:
4399:
3232:{\displaystyle R_{tamper}\gg R_{tamper}^{threshold}}
71:
can be further enhanced using a fissionable tamper.
4886:
4503:
4319:
4205:
3985:
3905:
3785:
3565:
3509:
3231:
3129:
2597:
2562:
2358:
2127:
2098:
1981:
1942:
1832:
1637:
1604:
1584:
1561:
1497:
1471:
1440:
1332:
1202:
1134:
968:
852:
830:
785:
744:
724:
697:
674:
82:tampers, but a heavy tamper necessitates a larger
4823:Volume III: The Development of US Nuclear Weapons
4192:
4108:
4092:
4008:
3892:
3808:
3769:
3685:
3669:
3585:
3435:
3351:
3335:
3251:
3055:
3042:
2958:
2942:
2858:
2851:
2844:
2617:
2533:
2483:
2329:
2279:
2216:
2173:
1825:
1712:
1127:
1069:
289:used with artillery pieces for the same reason.
4793:Volume I: The Development of US Nuclear Weapons
1203:{\displaystyle \tau =\lambda _{f}^{core}/v_{n}}
316:will fission when struck by a neutron with 1.6
158:
304:tamper, while the secondary has a heavyweight
4558:"4.4 Elements of Thermonuclear Weapon Design"
3566:{\displaystyle \lambda _{t}^{tamper}=\infty }
961:
924:
160:A similar envelope can be used to reduce the
8:
4626:
4602:
1562:{\displaystyle N_{tamper}={\frac {A}{r}}+B}
4656:– via National Library of Australia.
5164:. Princeton: Princeton University Press.
5088:Dark Sun: The Making of the Hydrogen Bomb
5064:
4957:
4309:
4286:
4252:
4232:
4226:
4224:
4191:
4190:
4173:
4139:
4119:
4113:
4107:
4106:
4091:
4090:
4073:
4039:
4019:
4013:
4007:
4006:
4004:
3968:
3963:
3935:
3930:
3924:
3891:
3890:
3873:
3839:
3819:
3813:
3807:
3806:
3804:
3768:
3767:
3750:
3716:
3696:
3690:
3684:
3683:
3668:
3667:
3650:
3616:
3596:
3590:
3584:
3583:
3581:
3536:
3531:
3525:
3490:
3485:
3460:
3455:
3449:
3434:
3433:
3416:
3382:
3362:
3356:
3350:
3349:
3334:
3333:
3316:
3282:
3262:
3256:
3250:
3249:
3247:
3199:
3179:
3151:
3145:
3104:
3099:
3074:
3069:
3063:
3054:
3053:
3041:
3040:
3023:
2989:
2969:
2963:
2957:
2956:
2941:
2940:
2923:
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2869:
2863:
2857:
2856:
2850:
2849:
2843:
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2819:
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2765:
2759:
2747:
2727:
2697:
2692:
2658:
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2628:
2616:
2615:
2613:
2578:
2543:
2538:
2532:
2531:
2498:
2488:
2482:
2481:
2460:
2455:
2441:
2411:
2383:
2377:
2339:
2334:
2328:
2327:
2294:
2284:
2278:
2277:
2256:
2251:
2227:
2222:
2215:
2214:
2188:
2178:
2172:
2171:
2170:
2154:
2149:
2143:
2114:
2078:
2050:
2025:
2003:
1997:
1964:
1958:
1918:
1913:
1894:
1889:
1881:
1857:
1851:
1824:
1823:
1795:
1786:
1779:
1773:
1739:
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1720:
1711:
1710:
1694:
1687:
1659:
1653:
1624:
1597:
1577:
1543:
1519:
1513:
1484:
1461:
1456:
1426:
1407:
1388:
1383:
1376:
1353:
1351:
1282:
1277:
1258:
1253:
1245:
1227:
1221:
1194:
1185:
1170:
1165:
1153:
1126:
1125:
1101:
1092:
1074:
1068:
1067:
1051:
1044:
1034:
997:
991:
960:
959:
939:
933:
923:
922:
907:
899:
890:
878:
872:
845:
813:
808:
802:
768:
763:
757:
737:
716:
710:
690:
660:
641:
622:
617:
610:
572:
567:
557:
551:
528:
526:
4893:. New York: Cambridge University Press.
4853:Volume V: U.S. Nuclear Weapons Histories
345:. It is estimated that up to 30% of the
300:warhead, the primary uses a lightweight
282:. Tungsten carbide was commonly used in
94:reflector, which is also transparent to
5186:
4881:; Henriksen, Paul W.; Meade, Roger A.;
4578:
4530:
4465:
4441:
4429:
4339:
981:separable partial differential equation
328:will exceed this threshold. However, a
4763:US Nuclear Weapons: The Secret History
4614:
4590:
4390:
4363:
144:describes the function of a tamper in
5123:. Berkeley: University of California.
4346:
74:The first nuclear weapons used heavy
7:
5014:The Physics of the Manhattan Project
4709:
4697:
4678:
4666:
4515:
4453:
4417:
4405:
5039:Reed, B. Cameron (September 2017).
4735:. Basingstoke: Palgrave Macmillan.
831:{\displaystyle \lambda _{t}^{core}}
786:{\displaystyle \lambda _{f}^{core}}
705:is the number density of neutrons,
137:Atomic Energy for Military Purposes
5091:. New York: Simon & Schuster.
5041:"Revisiting the Los Alamos Primer"
3780:
3560:
3140:If the tamper is really thick, ie
2521:
2491:
2317:
2287:
2205:
2181:
1423:
1364:
1356:
950:
942:
913:
909:
875:
657:
539:
531:
377:even with slow neutrons. A highly
25:
2598:{\displaystyle \alpha =\delta =0}
732:is the average neutron velocity,
5201:
5189:
4504:Semkow, Parekh & Haines 2005
186:with a tamper was introduced by
2128:{\displaystyle \alpha =\delta }
1451:Set the separation constant as
457:when irradiated with neutrons.
178:The concept of surrounding the
4640:""Never Intended" Cobalt Bomb"
2432:
2404:
2093:
2071:
2040:
2018:
1702:
1688:
1435:
1419:
1323:
1302:
1116:
1086:
1059:
1045:
1024:
1012:
669:
653:
601:
589:
90:may instead use a lightweight
1:
4765:. Arlington, Texas: Aerofax.
3239:this can be approximated as:
1472:{\displaystyle \delta /\tau }
122:, several generations of the
1638:{\displaystyle \delta >0}
397:was killed in May 1946 in a
4977:American Journal of Physics
3996:Then the equation becomes:
259:atomic bombing of Hiroshima
236:several generations of the
5240:
4942:10.1038/s41598-020-61201-0
864:in spherical coordinates:
31:
5012:Reed, B. Cameron (2011).
4216:which is satisfied when:
1498:{\displaystyle \delta =0}
403:Operation Tumbler–Snapper
349:came from fission of the
257:uranium bomb used in the
4560:. Nuclear Weapon Archive
3573:. The equation becomes:
1982:{\displaystyle R_{core}}
1614:constants of integration
287:gun-type nuclear weapons
228:, he predicted that the
29:Nuclear weapon component
18:Tamper (nuclear weapons)
4627:Arnold & Smith 2006
4603:Arnold & Smith 2006
4483:"The Fat Man's Uranium"
3796:which is satisfied by:
420:reactor-grade plutonium
34:Tamper (disambiguation)
4883:Westfall, Catherine L.
4729:; Smith, Mark (2006).
4321:
4207:
3987:
3907:
3787:
3567:
3511:
3233:
3131:
2599:
2564:
2360:
2129:
2100:
1983:
1944:
1834:
1639:
1606:
1586:
1563:
1499:
1473:
1442:
1334:
1204:
1136:
970:
854:
832:
787:
746:
726:
699:
676:
469:anti-ballistic missile
362:boosted fission weapon
309:
171:
5224:Nuclear weapon design
4322:
4208:
3988:
3908:
3788:
3568:
3512:
3234:
3132:
2600:
2565:
2361:
2130:
2101:
1984:
1945:
1835:
1640:
1607:
1587:
1564:
1500:
1474:
1443:
1335:
1205:
1137:
971:
855:
833:
788:
747:
727:
725:{\displaystyle v_{n}}
700:
677:
410:Alternative materials
295:
146:nuclear weapon design
53:nuclear weapon design
4379:Hoddeson et al. 1993
4223:
4003:
3923:
3803:
3580:
3524:
3246:
3144:
2612:
2577:
2376:
2142:
2113:
1996:
1957:
1850:
1652:
1623:
1596:
1576:
1512:
1483:
1455:
1350:
1220:
1152:
990:
871:
844:
801:
756:
745:{\displaystyle \nu }
736:
709:
689:
525:
464:warhead used in the
399:criticality accident
366:thermonuclear weapon
88:thermonuclear weapon
32:For other uses, see
5156:Smyth, Henry DeWolf
5057:2017PhT....70i..42R
4989:2009AmJPh..77..730R
4934:2020NatSR..10.4200K
4916:Khan, F A. (2020).
4629:, pp. 198–199.
4593:, pp. 194–195.
4533:, pp. 293–296.
4506:, pp. 142–159.
4281:
4168:
4068:
3982:
3955:
3868:
3745:
3645:
3556:
3504:
3480:
3411:
3311:
3228:
3118:
3094:
3018:
2918:
2814:
2752:
2717:
2687:
2573:For the case where
2480:
2276:
2168:
1932:
1908:
1402:
1296:
1272:
1184:
827:
782:
636:
586:
486:In the theoretical
276:spontaneous fission
5196:nuclear technology
4922:Scientific Reports
4317:
4228:
4203:
4115:
4015:
3983:
3959:
3926:
3903:
3815:
3783:
3692:
3592:
3563:
3527:
3507:
3481:
3451:
3358:
3258:
3229:
3175:
3127:
3095:
3065:
2965:
2865:
2761:
2723:
2688:
2634:
2595:
2560:
2451:
2356:
2247:
2145:
2125:
2096:
1979:
1940:
1909:
1885:
1830:
1635:
1602:
1582:
1559:
1495:
1469:
1438:
1379:
1330:
1273:
1249:
1200:
1161:
1132:
966:
850:
828:
804:
783:
759:
742:
722:
695:
672:
613:
563:
504:Tadje nuclear test
310:
148:as similar to the
142:Henry DeWolf Smyth
140:(1945), physicist
5171:978-0-8047-1722-9
5139:978-0-8412-3982-1
5120:Los Alamos Primer
5066:10.1063/PT.3.3692
5023:978-3-642-14708-1
4997:10.1119/1.3125008
4900:978-0-521-44132-2
4879:Hoddeson, Lillian
4862:978-0-9791915-5-8
4832:978-0-9791915-3-4
4802:978-0-9791915-1-0
4742:978-1-4039-2102-4
4556:Sublette, Carey.
4485:. Restricted Data
4479:Wellerstein, Alex
4456:, pp. 30–31.
4393:, pp. 14–15.
4301:
4188:
4088:
3888:
3765:
3665:
3505:
3431:
3331:
3119:
3038:
2938:
2840:
2754:
2528:
2449:
2324:
2212:
1938:
1937:
1821:
1765:
1605:{\displaystyle B}
1585:{\displaystyle A}
1551:
1417:
1371:
1328:
1327:
1123:
957:
920:
905:
853:{\displaystyle N}
698:{\displaystyle N}
651:
587:
546:
337:type used in the
318:megaelectronvolts
198:Manhattan Project
193:Los Alamos Primer
150:neutron reflector
65:neutron reflector
16:(Redirected from
5231:
5206:
5205:
5194:
5193:
5192:
5185:
5175:
5151:
5124:
5110:
5078:
5068:
5035:
5008:
4971:
4961:
4912:
4892:
4874:
4844:
4814:
4784:
4754:
4713:
4707:
4701:
4695:
4682:
4676:
4670:
4664:
4658:
4657:
4655:
4653:
4636:
4630:
4624:
4618:
4612:
4606:
4600:
4594:
4588:
4582:
4576:
4570:
4569:
4567:
4565:
4553:
4534:
4528:
4519:
4513:
4507:
4501:
4495:
4494:
4492:
4490:
4475:
4469:
4463:
4457:
4451:
4445:
4439:
4433:
4427:
4421:
4415:
4409:
4403:
4394:
4388:
4382:
4376:
4367:
4361:
4350:
4344:
4326:
4324:
4323:
4318:
4313:
4302:
4300:
4299:
4280:
4251:
4227:
4212:
4210:
4209:
4204:
4196:
4195:
4189:
4187:
4186:
4167:
4138:
4114:
4112:
4111:
4096:
4095:
4089:
4087:
4086:
4067:
4038:
4014:
4012:
4011:
3992:
3990:
3989:
3984:
3981:
3967:
3954:
3934:
3912:
3910:
3909:
3904:
3896:
3895:
3889:
3887:
3886:
3867:
3838:
3814:
3812:
3811:
3792:
3790:
3789:
3784:
3773:
3772:
3766:
3764:
3763:
3744:
3715:
3691:
3689:
3688:
3673:
3672:
3666:
3664:
3663:
3644:
3615:
3591:
3589:
3588:
3572:
3570:
3569:
3564:
3555:
3535:
3516:
3514:
3513:
3508:
3506:
3503:
3489:
3479:
3459:
3450:
3439:
3438:
3432:
3430:
3429:
3410:
3381:
3357:
3355:
3354:
3339:
3338:
3332:
3330:
3329:
3310:
3281:
3257:
3255:
3254:
3238:
3236:
3235:
3230:
3227:
3198:
3171:
3170:
3136:
3134:
3133:
3128:
3120:
3117:
3103:
3093:
3073:
3064:
3059:
3058:
3046:
3045:
3039:
3037:
3036:
3017:
2988:
2964:
2962:
2961:
2946:
2945:
2939:
2937:
2936:
2917:
2888:
2864:
2862:
2861:
2855:
2854:
2848:
2847:
2841:
2839:
2838:
2813:
2784:
2760:
2755:
2753:
2751:
2746:
2718:
2716:
2696:
2686:
2657:
2629:
2621:
2620:
2604:
2602:
2601:
2596:
2569:
2567:
2566:
2561:
2559:
2558:
2557:
2556:
2537:
2536:
2529:
2527:
2519:
2518:
2517:
2489:
2487:
2486:
2479:
2459:
2450:
2442:
2431:
2430:
2403:
2402:
2365:
2363:
2362:
2357:
2355:
2354:
2353:
2352:
2333:
2332:
2325:
2323:
2315:
2314:
2313:
2285:
2283:
2282:
2275:
2255:
2243:
2242:
2241:
2240:
2221:
2220:
2219:
2213:
2211:
2203:
2202:
2201:
2179:
2177:
2176:
2167:
2153:
2134:
2132:
2131:
2126:
2105:
2103:
2102:
2097:
2092:
2091:
2070:
2069:
2039:
2038:
2017:
2016:
1988:
1986:
1985:
1980:
1978:
1977:
1949:
1947:
1946:
1941:
1939:
1933:
1931:
1917:
1907:
1893:
1883:
1882:
1877:
1876:
1839:
1837:
1836:
1831:
1829:
1828:
1822:
1817:
1816:
1815:
1814:
1790:
1774:
1766:
1761:
1760:
1759:
1758:
1734:
1721:
1716:
1715:
1709:
1708:
1698:
1679:
1678:
1644:
1642:
1641:
1636:
1611:
1609:
1608:
1603:
1591:
1589:
1588:
1583:
1568:
1566:
1565:
1560:
1552:
1544:
1539:
1538:
1504:
1502:
1501:
1496:
1478:
1476:
1475:
1470:
1465:
1447:
1445:
1444:
1439:
1431:
1430:
1418:
1413:
1412:
1411:
1401:
1387:
1377:
1372:
1370:
1362:
1354:
1339:
1337:
1336:
1331:
1329:
1326:
1297:
1295:
1281:
1271:
1257:
1247:
1246:
1241:
1240:
1209:
1207:
1206:
1201:
1199:
1198:
1189:
1183:
1169:
1141:
1139:
1138:
1133:
1131:
1130:
1124:
1119:
1115:
1114:
1096:
1075:
1073:
1072:
1066:
1065:
1055:
1039:
1038:
1011:
1010:
975:
973:
972:
967:
965:
964:
958:
956:
948:
940:
938:
937:
928:
927:
921:
919:
908:
906:
904:
903:
891:
883:
882:
862:Laplace operator
859:
857:
856:
851:
837:
835:
834:
829:
826:
812:
792:
790:
789:
784:
781:
767:
751:
749:
748:
743:
731:
729:
728:
723:
721:
720:
704:
702:
701:
696:
681:
679:
678:
673:
665:
664:
652:
647:
646:
645:
635:
621:
611:
588:
585:
571:
562:
561:
552:
547:
545:
537:
529:
379:enriched uranium
272:depleted uranium
263:tungsten carbide
243:fissile material
226:diffusion theory
80:tungsten carbide
51:. It is used in
49:fissile material
21:
5239:
5238:
5234:
5233:
5232:
5230:
5229:
5228:
5214:
5213:
5212:
5200:
5190:
5188:
5180:
5178:
5172:
5154:
5140:
5127:
5113:
5099:
5083:Rhodes, Richard
5081:
5038:
5024:
5011:
4974:
4915:
4901:
4877:
4863:
4847:
4833:
4817:
4803:
4787:
4773:
4757:
4743:
4725:
4721:
4716:
4708:
4704:
4696:
4685:
4677:
4673:
4665:
4661:
4651:
4649:
4638:
4637:
4633:
4625:
4621:
4613:
4609:
4601:
4597:
4589:
4585:
4577:
4573:
4563:
4561:
4555:
4554:
4537:
4529:
4522:
4514:
4510:
4502:
4498:
4488:
4486:
4477:
4476:
4472:
4464:
4460:
4452:
4448:
4440:
4436:
4428:
4424:
4416:
4412:
4404:
4397:
4389:
4385:
4377:
4370:
4366:, pp. 7–8.
4362:
4353:
4345:
4341:
4337:
4282:
4221:
4220:
4169:
4069:
4001:
4000:
3921:
3920:
3869:
3801:
3800:
3746:
3646:
3578:
3577:
3522:
3521:
3412:
3312:
3244:
3243:
3147:
3142:
3141:
3019:
2919:
2815:
2719:
2630:
2610:
2609:
2575:
2574:
2539:
2530:
2520:
2494:
2490:
2407:
2379:
2374:
2373:
2335:
2326:
2316:
2290:
2286:
2223:
2204:
2184:
2180:
2169:
2140:
2139:
2111:
2110:
2074:
2046:
2021:
1999:
1994:
1993:
1960:
1955:
1954:
1884:
1853:
1848:
1847:
1791:
1775:
1735:
1722:
1683:
1655:
1650:
1649:
1621:
1620:
1594:
1593:
1574:
1573:
1515:
1510:
1509:
1481:
1480:
1453:
1452:
1422:
1403:
1378:
1363:
1355:
1348:
1347:
1298:
1248:
1223:
1218:
1217:
1190:
1150:
1149:
1097:
1076:
1040:
1030:
993:
988:
987:
949:
941:
929:
912:
895:
874:
869:
868:
842:
841:
799:
798:
793:is the fission
754:
753:
734:
733:
712:
707:
706:
687:
686:
656:
637:
612:
553:
538:
530:
523:
522:
516:
455:gamma radiation
451:nuclear fallout
412:
357:of the tamper.
351:natural uranium
176:
154:nuclear reactor
132:
108:nuclear fallout
76:natural uranium
37:
30:
23:
22:
15:
12:
11:
5:
5237:
5235:
5227:
5226:
5216:
5215:
5211:
5210:
5198:
5177:
5176:
5170:
5152:
5138:
5125:
5115:Serber, Robert
5111:
5097:
5079:
5036:
5022:
5009:
4983:(8): 730–733.
4972:
4913:
4899:
4875:
4861:
4845:
4831:
4815:
4801:
4785:
4771:
4755:
4741:
4722:
4720:
4717:
4715:
4714:
4702:
4700:, p. 732.
4683:
4681:, p. 730.
4671:
4659:
4631:
4619:
4617:, p. 189.
4607:
4595:
4583:
4581:, p. 179.
4571:
4535:
4520:
4508:
4496:
4470:
4468:, p. 292.
4458:
4446:
4444:, p. 108.
4434:
4432:, p. 273.
4422:
4410:
4395:
4383:
4368:
4351:
4349:, p. 210.
4338:
4336:
4333:
4328:
4327:
4316:
4312:
4308:
4305:
4298:
4295:
4292:
4289:
4285:
4279:
4276:
4273:
4270:
4267:
4264:
4261:
4258:
4255:
4250:
4247:
4244:
4241:
4238:
4235:
4231:
4214:
4213:
4202:
4199:
4194:
4185:
4182:
4179:
4176:
4172:
4166:
4163:
4160:
4157:
4154:
4151:
4148:
4145:
4142:
4137:
4134:
4131:
4128:
4125:
4122:
4118:
4110:
4105:
4102:
4099:
4094:
4085:
4082:
4079:
4076:
4072:
4066:
4063:
4060:
4057:
4054:
4051:
4048:
4045:
4042:
4037:
4034:
4031:
4028:
4025:
4022:
4018:
4010:
3994:
3993:
3980:
3977:
3974:
3971:
3966:
3962:
3958:
3953:
3950:
3947:
3944:
3941:
3938:
3933:
3929:
3914:
3913:
3902:
3899:
3894:
3885:
3882:
3879:
3876:
3872:
3866:
3863:
3860:
3857:
3854:
3851:
3848:
3845:
3842:
3837:
3834:
3831:
3828:
3825:
3822:
3818:
3810:
3794:
3793:
3782:
3779:
3776:
3771:
3762:
3759:
3756:
3753:
3749:
3743:
3740:
3737:
3734:
3731:
3728:
3725:
3722:
3719:
3714:
3711:
3708:
3705:
3702:
3699:
3695:
3687:
3682:
3679:
3676:
3671:
3662:
3659:
3656:
3653:
3649:
3643:
3640:
3637:
3634:
3631:
3628:
3625:
3622:
3619:
3614:
3611:
3608:
3605:
3602:
3599:
3595:
3587:
3562:
3559:
3554:
3551:
3548:
3545:
3542:
3539:
3534:
3530:
3518:
3517:
3502:
3499:
3496:
3493:
3488:
3484:
3478:
3475:
3472:
3469:
3466:
3463:
3458:
3454:
3448:
3445:
3442:
3437:
3428:
3425:
3422:
3419:
3415:
3409:
3406:
3403:
3400:
3397:
3394:
3391:
3388:
3385:
3380:
3377:
3374:
3371:
3368:
3365:
3361:
3353:
3348:
3345:
3342:
3337:
3328:
3325:
3322:
3319:
3315:
3309:
3306:
3303:
3300:
3297:
3294:
3291:
3288:
3285:
3280:
3277:
3274:
3271:
3268:
3265:
3261:
3253:
3226:
3223:
3220:
3217:
3214:
3211:
3208:
3205:
3202:
3197:
3194:
3191:
3188:
3185:
3182:
3178:
3174:
3169:
3166:
3163:
3160:
3157:
3154:
3150:
3138:
3137:
3126:
3123:
3116:
3113:
3110:
3107:
3102:
3098:
3092:
3089:
3086:
3083:
3080:
3077:
3072:
3068:
3062:
3057:
3052:
3049:
3044:
3035:
3032:
3029:
3026:
3022:
3016:
3013:
3010:
3007:
3004:
3001:
2998:
2995:
2992:
2987:
2984:
2981:
2978:
2975:
2972:
2968:
2960:
2955:
2952:
2949:
2944:
2935:
2932:
2929:
2926:
2922:
2916:
2913:
2910:
2907:
2904:
2901:
2898:
2895:
2892:
2887:
2884:
2881:
2878:
2875:
2872:
2868:
2860:
2853:
2846:
2837:
2834:
2831:
2828:
2825:
2822:
2818:
2812:
2809:
2806:
2803:
2800:
2797:
2794:
2791:
2788:
2783:
2780:
2777:
2774:
2771:
2768:
2764:
2758:
2750:
2745:
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2733:
2730:
2726:
2722:
2715:
2712:
2709:
2706:
2703:
2700:
2695:
2691:
2685:
2682:
2679:
2676:
2673:
2670:
2667:
2664:
2661:
2656:
2653:
2650:
2647:
2644:
2641:
2637:
2633:
2627:
2624:
2619:
2594:
2591:
2588:
2585:
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2250:
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2210:
2207:
2200:
2197:
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2175:
2166:
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2160:
2157:
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2124:
2121:
2118:
2107:
2106:
2095:
2090:
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2065:
2062:
2059:
2056:
2053:
2049:
2045:
2042:
2037:
2034:
2031:
2028:
2024:
2020:
2015:
2012:
2009:
2006:
2002:
1976:
1973:
1970:
1967:
1963:
1951:
1950:
1936:
1930:
1927:
1924:
1921:
1916:
1912:
1906:
1903:
1900:
1897:
1892:
1888:
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1197:
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1164:
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1157:
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1129:
1122:
1118:
1113:
1110:
1107:
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1100:
1095:
1091:
1088:
1085:
1082:
1079:
1071:
1064:
1061:
1058:
1054:
1050:
1047:
1043:
1037:
1033:
1029:
1026:
1023:
1020:
1017:
1014:
1009:
1006:
1003:
1000:
996:
977:
976:
963:
955:
952:
947:
944:
936:
932:
926:
918:
915:
911:
902:
898:
894:
889:
886:
881:
877:
849:
825:
822:
819:
816:
811:
807:
795:mean free path
780:
777:
774:
771:
766:
762:
741:
719:
715:
694:
683:
682:
671:
668:
663:
659:
655:
650:
644:
640:
634:
631:
628:
625:
620:
616:
609:
606:
603:
600:
597:
594:
591:
584:
581:
578:
575:
570:
566:
560:
556:
550:
544:
541:
536:
533:
515:
512:
477:beta particles
466:LIM-49 Spartan
411:
408:
238:chain reaction
184:nuclear weapon
175:
172:
131:
128:
124:chain reaction
84:high-explosive
55:to reduce the
41:nuclear weapon
28:
24:
14:
13:
10:
9:
6:
4:
3:
2:
5236:
5225:
5222:
5221:
5219:
5209:
5204:
5199:
5197:
5187:
5183:
5173:
5167:
5163:
5162:
5157:
5153:
5149:
5145:
5141:
5135:
5131:
5126:
5122:
5121:
5116:
5112:
5108:
5104:
5100:
5098:0-684-80400-X
5094:
5090:
5089:
5084:
5080:
5076:
5072:
5067:
5062:
5058:
5054:
5050:
5046:
5045:Physics Today
5042:
5037:
5033:
5029:
5025:
5019:
5015:
5010:
5006:
5002:
4998:
4994:
4990:
4986:
4982:
4978:
4973:
4969:
4965:
4960:
4955:
4951:
4947:
4943:
4939:
4935:
4931:
4927:
4923:
4919:
4914:
4910:
4906:
4902:
4896:
4891:
4890:
4884:
4880:
4876:
4872:
4868:
4864:
4858:
4854:
4850:
4849:Hansen, Chuck
4846:
4842:
4838:
4834:
4828:
4824:
4820:
4819:Hansen, Chuck
4816:
4812:
4808:
4804:
4798:
4794:
4790:
4789:Hansen, Chuck
4786:
4782:
4778:
4774:
4772:0-517-56740-7
4768:
4764:
4760:
4759:Hansen, Chuck
4756:
4752:
4748:
4744:
4738:
4734:
4733:
4728:
4727:Arnold, Lorna
4724:
4723:
4718:
4712:, p. 56.
4711:
4706:
4703:
4699:
4694:
4692:
4690:
4688:
4684:
4680:
4675:
4672:
4669:, p. 52.
4668:
4663:
4660:
4647:
4646:
4641:
4635:
4632:
4628:
4623:
4620:
4616:
4611:
4608:
4605:, p. 17.
4604:
4599:
4596:
4592:
4587:
4584:
4580:
4575:
4572:
4559:
4552:
4550:
4548:
4546:
4544:
4542:
4540:
4536:
4532:
4527:
4525:
4521:
4517:
4512:
4509:
4505:
4500:
4497:
4484:
4480:
4474:
4471:
4467:
4462:
4459:
4455:
4450:
4447:
4443:
4438:
4435:
4431:
4426:
4423:
4420:, p. 57.
4419:
4414:
4411:
4408:, p. 46.
4407:
4402:
4400:
4396:
4392:
4387:
4384:
4381:, p. 72.
4380:
4375:
4373:
4369:
4365:
4360:
4358:
4356:
4352:
4348:
4343:
4340:
4334:
4332:
4314:
4310:
4306:
4303:
4296:
4293:
4290:
4287:
4283:
4277:
4274:
4271:
4268:
4265:
4262:
4259:
4256:
4253:
4248:
4245:
4242:
4239:
4236:
4233:
4229:
4219:
4218:
4217:
4200:
4197:
4183:
4180:
4177:
4174:
4170:
4164:
4161:
4158:
4155:
4152:
4149:
4146:
4143:
4140:
4135:
4132:
4129:
4126:
4123:
4120:
4116:
4103:
4100:
4097:
4083:
4080:
4077:
4074:
4070:
4064:
4061:
4058:
4055:
4052:
4049:
4046:
4043:
4040:
4035:
4032:
4029:
4026:
4023:
4020:
4016:
3999:
3998:
3997:
3978:
3975:
3972:
3969:
3964:
3960:
3956:
3951:
3948:
3945:
3942:
3939:
3936:
3931:
3927:
3919:
3918:
3917:
3900:
3897:
3883:
3880:
3877:
3874:
3870:
3864:
3861:
3858:
3855:
3852:
3849:
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3843:
3840:
3835:
3832:
3829:
3826:
3823:
3820:
3816:
3799:
3798:
3797:
3777:
3774:
3760:
3757:
3754:
3751:
3747:
3741:
3738:
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3723:
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3717:
3712:
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3706:
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3700:
3697:
3693:
3680:
3677:
3674:
3660:
3657:
3654:
3651:
3647:
3641:
3638:
3635:
3632:
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3620:
3617:
3612:
3609:
3606:
3603:
3600:
3597:
3593:
3576:
3575:
3574:
3557:
3552:
3549:
3546:
3543:
3540:
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3532:
3528:
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3497:
3494:
3491:
3486:
3482:
3476:
3473:
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3461:
3456:
3452:
3446:
3443:
3440:
3426:
3423:
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3417:
3413:
3407:
3404:
3401:
3398:
3395:
3392:
3389:
3386:
3383:
3378:
3375:
3372:
3369:
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3363:
3359:
3346:
3343:
3340:
3326:
3323:
3320:
3317:
3313:
3307:
3304:
3301:
3298:
3295:
3292:
3289:
3286:
3283:
3278:
3275:
3272:
3269:
3266:
3263:
3259:
3242:
3241:
3240:
3224:
3221:
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3215:
3212:
3209:
3206:
3203:
3200:
3195:
3192:
3189:
3186:
3183:
3180:
3176:
3172:
3167:
3164:
3161:
3158:
3155:
3152:
3148:
3124:
3121:
3114:
3111:
3108:
3105:
3100:
3096:
3090:
3087:
3084:
3081:
3078:
3075:
3070:
3066:
3060:
3050:
3047:
3033:
3030:
3027:
3024:
3020:
3014:
3011:
3008:
3005:
3002:
2999:
2996:
2993:
2990:
2985:
2982:
2979:
2976:
2973:
2970:
2966:
2953:
2950:
2947:
2933:
2930:
2927:
2924:
2920:
2914:
2911:
2908:
2905:
2902:
2899:
2896:
2893:
2890:
2885:
2882:
2879:
2876:
2873:
2870:
2866:
2835:
2832:
2829:
2826:
2823:
2820:
2816:
2810:
2807:
2804:
2801:
2798:
2795:
2792:
2789:
2786:
2781:
2778:
2775:
2772:
2769:
2766:
2762:
2756:
2748:
2743:
2740:
2737:
2734:
2731:
2728:
2724:
2720:
2713:
2710:
2707:
2704:
2701:
2698:
2693:
2689:
2683:
2680:
2677:
2674:
2671:
2668:
2665:
2662:
2659:
2654:
2651:
2648:
2645:
2642:
2639:
2635:
2631:
2625:
2622:
2608:
2607:
2606:
2592:
2589:
2586:
2583:
2580:
2553:
2550:
2547:
2544:
2540:
2524:
2514:
2511:
2508:
2505:
2502:
2499:
2495:
2476:
2473:
2470:
2467:
2464:
2461:
2456:
2452:
2446:
2443:
2438:
2435:
2427:
2424:
2421:
2418:
2415:
2412:
2408:
2399:
2396:
2393:
2390:
2387:
2384:
2380:
2372:
2371:
2370:
2349:
2346:
2343:
2340:
2336:
2320:
2310:
2307:
2304:
2301:
2298:
2295:
2291:
2272:
2269:
2266:
2263:
2260:
2257:
2252:
2248:
2244:
2237:
2234:
2231:
2228:
2224:
2208:
2198:
2195:
2192:
2189:
2185:
2164:
2161:
2158:
2155:
2150:
2146:
2138:
2137:
2136:
2122:
2119:
2116:
2088:
2085:
2082:
2079:
2075:
2066:
2063:
2060:
2057:
2054:
2051:
2047:
2043:
2035:
2032:
2029:
2026:
2022:
2013:
2010:
2007:
2004:
2000:
1992:
1991:
1990:
1974:
1971:
1968:
1965:
1961:
1934:
1928:
1925:
1922:
1919:
1914:
1910:
1904:
1901:
1898:
1895:
1890:
1886:
1878:
1873:
1870:
1867:
1864:
1861:
1858:
1854:
1846:
1845:
1844:
1818:
1811:
1808:
1805:
1802:
1799:
1796:
1792:
1787:
1783:
1780:
1776:
1770:
1767:
1762:
1755:
1752:
1749:
1746:
1743:
1740:
1736:
1731:
1727:
1723:
1717:
1705:
1699:
1695:
1691:
1684:
1680:
1675:
1672:
1669:
1666:
1663:
1660:
1656:
1648:
1647:
1646:
1632:
1629:
1626:
1617:
1615:
1599:
1579:
1556:
1553:
1548:
1545:
1540:
1535:
1532:
1529:
1526:
1523:
1520:
1516:
1508:
1507:
1506:
1492:
1489:
1486:
1466:
1462:
1458:
1432:
1427:
1414:
1408:
1404:
1398:
1395:
1392:
1389:
1384:
1380:
1373:
1367:
1359:
1346:
1345:
1344:
1320:
1317:
1314:
1311:
1308:
1305:
1299:
1292:
1289:
1286:
1283:
1278:
1274:
1268:
1265:
1262:
1259:
1254:
1250:
1242:
1237:
1234:
1231:
1228:
1224:
1216:
1215:
1214:
1195:
1191:
1186:
1180:
1177:
1174:
1171:
1166:
1162:
1158:
1155:
1148:
1147:
1146:
1120:
1111:
1108:
1105:
1102:
1098:
1093:
1089:
1083:
1080:
1077:
1062:
1056:
1052:
1048:
1041:
1035:
1031:
1027:
1021:
1018:
1015:
1007:
1004:
1001:
998:
994:
986:
985:
984:
982:
953:
945:
934:
930:
916:
900:
896:
892:
887:
884:
879:
867:
866:
865:
863:
847:
839:
823:
820:
817:
814:
809:
805:
796:
778:
775:
772:
769:
764:
760:
739:
717:
713:
692:
666:
661:
648:
642:
638:
632:
629:
626:
623:
618:
614:
607:
604:
598:
595:
592:
582:
579:
576:
573:
568:
564:
558:
554:
548:
542:
534:
521:
520:
519:
513:
511:
509:
505:
501:
497:
493:
489:
484:
482:
478:
474:
470:
467:
463:
458:
456:
452:
448:
444:
440:
439:nuclear tests
435:
433:
429:
428:plutonium-239
425:
421:
416:
409:
407:
404:
400:
396:
391:
388:
383:
380:
375:
371:
367:
363:
358:
356:
352:
348:
344:
340:
336:
331:
327:
323:
319:
315:
307:
303:
299:
294:
290:
288:
285:
281:
280:predetonation
277:
273:
269:
268:cross section
264:
260:
256:
251:
249:
244:
239:
233:
231:
230:critical mass
227:
223:
219:
215:
211:
207:
203:
199:
195:
194:
189:
188:Robert Serber
185:
181:
173:
170:
167:
163:
162:critical size
157:
155:
151:
147:
143:
139:
138:
129:
127:
125:
121:
116:
111:
109:
105:
101:
97:
93:
89:
85:
81:
77:
72:
70:
66:
62:
58:
57:critical mass
54:
50:
46:
42:
35:
27:
19:
5160:
5129:
5119:
5087:
5051:(9): 42–49.
5048:
5044:
5013:
4980:
4976:
4925:
4921:
4888:
4852:
4822:
4792:
4762:
4731:
4705:
4674:
4662:
4650:. Retrieved
4643:
4634:
4622:
4610:
4598:
4586:
4579:Hansen 1995c
4574:
4562:. Retrieved
4531:Hansen 1995a
4511:
4499:
4487:. Retrieved
4473:
4466:Hansen 1995a
4461:
4449:
4442:Hansen 1995e
4437:
4430:Hansen 1995a
4425:
4413:
4386:
4342:
4329:
4215:
3995:
3915:
3795:
3519:
3139:
2572:
2368:
2108:
1952:
1842:
1618:
1571:
1450:
1342:
1212:
1144:
979:Solving the
978:
840:
684:
517:
485:
459:
436:
413:
395:Louis Slotin
392:
384:
359:
355:photofission
339:Trinity test
330:fast neutron
311:
252:
234:
191:
177:
159:
135:
133:
112:
73:
44:
38:
26:
4928:(1): 4200.
4645:The Mercury
4615:Hansen 1988
4591:Rhodes 1995
4391:Serber 1943
4364:Serber 1943
488:cobalt bomb
326:uranium-235
320:(0.26
314:Uranium-238
306:uranium-235
284:uranium-233
5032:1195449878
4719:References
4347:Smyth 1945
983:gives us:
255:Little Boy
152:used in a
5148:984760244
5075:0031-9228
5005:0002-9505
4950:2045-2322
4871:231585284
4851:(1995e).
4841:231585284
4821:(1995c).
4811:231585284
4791:(1995a).
4781:749870939
4710:Reed 2011
4698:Reed 2009
4679:Reed 2009
4667:Reed 2011
4564:18 August
4516:Khan 2020
4489:17 August
4454:Reed 2017
4418:Reed 2017
4406:Reed 2011
4307:π
3961:λ
3957:∼
3928:λ
3901:π
3781:∞
3778:−
3561:∞
3529:λ
3483:λ
3453:λ
3447:−
3173:≫
3097:λ
3067:λ
3048:−
2757:−
2690:λ
2587:δ
2581:α
2522:∂
2492:∂
2453:λ
2439:−
2318:∂
2288:∂
2249:λ
2206:∂
2182:∂
2147:λ
2123:δ
2117:α
1911:λ
1887:λ
1781:−
1700:τ
1692:δ
1627:δ
1487:δ
1467:τ
1459:δ
1424:∇
1381:λ
1365:∂
1357:∂
1318:−
1315:ν
1309:α
1306:−
1275:λ
1251:λ
1163:λ
1156:τ
1057:τ
1049:α
951:∂
943:∂
914:∂
910:∂
876:∇
806:λ
761:λ
740:ν
658:∇
615:λ
596:−
593:ν
565:λ
540:∂
532:∂
508:Maralinga
500:cobalt-60
473:half-life
387:beryllium
370:deuterium
343:aluminium
302:beryllium
248:plutonium
92:beryllium
5218:Category
5158:(1945).
5117:(1943).
5107:32509950
5085:(1995).
4968:32144384
4909:26764320
4885:(1993).
4761:(1988).
4751:70673342
481:tantalum
424:boron-10
214:tungsten
130:Function
115:neutrons
5208:physics
5182:Portals
5053:Bibcode
4985:Bibcode
4959:7060208
4930:Bibcode
514:Physics
496:ionizes
447:bismuth
415:Thorium
374:tritium
335:Fat Man
296:In the
222:neutron
218:uranium
210:rhenium
202:inertia
190:in his
174:History
166:inertia
100:ionized
61:inertia
5168:
5146:
5136:
5105:
5095:
5073:
5030:
5020:
5003:
4966:
4956:
4948:
4907:
4897:
4869:
4859:
4839:
4829:
4809:
4799:
4779:
4769:
4749:
4739:
4652:9 July
1989:then:
1843:where
1572:Where
1145:where
685:where
492:cobalt
261:had a
96:X-rays
45:tamper
4335:Notes
2135:and:
1479:. If
432:boron
364:or a
360:In a
347:yield
308:one.
182:of a
98:when
69:yield
39:In a
5166:ISBN
5144:OCLC
5134:ISBN
5103:OCLC
5093:ISBN
5071:ISSN
5028:OCLC
5018:ISBN
5001:ISSN
4964:PMID
4946:ISSN
4905:OCLC
4895:ISBN
4867:OCLC
4857:ISBN
4837:OCLC
4827:ISBN
4807:OCLC
4797:ISBN
4777:OCLC
4767:ISBN
4747:OCLC
4737:ISBN
4654:2020
4566:2021
4491:2021
1630:>
1612:are
1592:and
1213:and
797:and
460:The
443:lead
253:The
216:and
206:gold
180:core
120:core
104:gold
43:, a
5061:doi
4993:doi
4954:PMC
4938:doi
1619:If
506:at
462:W71
434:.
298:W88
134:In
78:or
5220::
5142:.
5101:.
5069:.
5059:.
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5047:.
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4999:.
4991:.
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4979:.
4962:.
4952:.
4944:.
4936:.
4926:10
4924:.
4920:.
4903:.
4865:.
4835:.
4805:.
4775:.
4745:.
4686:^
4642:.
4538:^
4523:^
4481:.
4398:^
4371:^
4354:^
2605::
1616:.
490:,
322:pJ
212:,
208:,
156::
110:.
5184::
5174:.
5150:.
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5077:.
5063::
5055::
5034:.
5007:.
4995::
4987::
4970:.
4940::
4932::
4911:.
4873:.
4843:.
4813:.
4783:.
4753:.
4568:.
4518:.
4493:.
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4311:/
4304:=
4297:e
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4198:=
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2019:(
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