408:, weighed 7,400 lb (3,400 kg) and was 56 inches (140 cm) in diameter and 66 inches (170 cm) long. The nuclear system weighed 6,750 lb (3,060 kg). Defying the 1.5–3 kt predictions, its actual yield was only 200 tons. Wally Decker, a young Laboratory engineer, characterized the sound the shot made as "pop." The device failed to "automatically declassify" its test site, where the lower 100 ft (30 m) of the 300-foot (91 m) testing tower remained intact, the middle third scattered across the test area and only the upper third vaporized.
205:. In reality the result was that the slower neutrons delayed the reaction time too much by reducing the number of fission generations accomplished; especially as the core expanded to reach its snowplow region (where all nuclear reactions cease), more neutrons could escape from the turbulent surface of the core, and before enough energy (for military applications) could be produced. In all, neutron moderation sharply reduced the efficiency of the weapon before the
111:
246:
137:, in 1943, uranium deuteride was investigated as a promising bomb material; it was abandoned by early 1944 as it turned out such design would be inefficient. The "autocatalytic" design that emerged from this early research was "Elmer", the discontinued radial-implosion Mark 2 weapon. It made use of uranium deuteride particles coated with paraffin (to reduce the
209:
confinement failed. It was realized that the result would be a fizzle instead of full-scale detonation. The predicted yield was around 1 kilotonne of TNT (4.2 TJ), if the core operated as originally expected; the first rough estimate for the behavior of the "hydride" bomb appeared in 1944, when
200:
needed. At the same time, due to the moderating effect of deuterium, the compression requirements are (at least in principle) relaxed somewhat, which would permit assembly of additional fissile material in the core, as well as a radial-implosion assembly, which was much simpler and compact than the
333:. It was hoped that deuterium would fuse (become an active medium) in the secondary's core if compressed appropriately through radiation implosion. The fuel was selected so that UCRL's thermonuclear program would not compete with LASL's on scarce materials at the time, specifically
267:
305:). Optimism in the new lab prompted UCRL to even propose a class of such "small weapons" making use of the material, dubbing it as the "Geode". The "Geode"-type devices would be compact, linear (two-point) implosion, gas-boosted fission weapons using hollow
268:
341:
prototype designed by UCRL at the time. For a hydride-type primary, the degree of compression would not make deuterium to fuse, thus the design would be essentially a pure fission weapon, not a boosted one. The devices themselves as tested in
269:
489:
The idea of cheap thermonuclear fuels was pursued by UCRL with the design of the "Water Boiler", a primitive type of two-stage thermonuclear gadgets and an early design concept of the "Radiator", that would use heavy water solutions of
419:
HE assembly; it was likewise initiated by an XMC-305 betatron fired at known time. Being a sister device to "Hydride I", the "Hydride II" device only had a different pit "fuel" mix, and shared the same dimensions and weight with the
392:, which used deuterium and enriched uranium in a solid spherical pit with a natural uranium tamper, was the first device almost-entirely designed at Livermore; it was fired on March 31, 1953, at 05:00 local time (13:00 GMT) at
494:. They were essentially transferred from LASL to UCRL and follow-up investigations to experiments from 1952 conducted in LASL on behalf of Teller, and shortly before the latter's departure from LASL to the newly fledged UCRL.
271:
234:, strong skepticism arose as the inherently low efficiency of the fuel would not improve even remotely as theoretically envisioned when a hollow core and boosting were incorporated, and a proposed test of such a core in an
313:
producing yields of the order of 10 kt. Applications for this class of devices would be tactical nuclear weapons, as well as primaries for compact thermonuclear systems. The "Geodes" were essentially forerunners of the
229:
physicists continued research on the subject at low priority; while a Monte-Carlo simulation in
December 1949 showed that the core could in principle work and result in a weapon considerably smaller than the
424:
test device. It was fired in a cab, atop a 100-foot (30 m) tower on April 11, 1953. Although shot Ray leveled its tower, the yield was a meager 220 tons; while it did better than
68:
The term hydride for this type of weapon has been subject to misunderstandings in the open literature. While "hydride" might imply that natural hydrogen (which is mostly
270:
59:). Bomb efficiency was harmed by the slowing of neutrons since the latter delays the reaction, as delineated by Rob Serber in his 1992 extension of the original
337:. If successful, the devices could also lead to a compact primary containing minimal amount of fissile material, and powerful enough to ignite Ramrod the other
322:
298:
329:
for a spherical deuterated polyethylene charge containing uranium deuteride as a candidate thermonuclear fuel for the "Radiator", an early incarnation of the
415:
event, used deuterium and a different concentration of enriched uranium in its solid spherical pit. The device was called "Hydride II", and it also used a
302:
684:
309:
metallic uranium, or partially ("slightly") moderated cores, where a metallic uranium or plutonium shell was lined internally with UD
697:
462:
The distribution of boron-10 was apparently more useful, and it did away with the earlier and cumbersome "Boron Bubble" scheme.
346:
were experimental systems, not weapon prototypes, and were not designed to be used as weapons, or thermonuclear primaries. The
226:
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Two test devices were fielded in 1953 as part of operation Upshot–Knothole. The principal aim of the
239:
73:
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47:
in a uranium-deuterium ceramic compact. Unlike all other fission-bomb types, the concept relies on a
732:
471:
hence the name geodes, which usually consist of spheroidal cavities lined internally with crystals.
416:
397:
235:
231:
202:
56:
253:
showing the MK 2 "Elmer" and the MK 8 "Elsie" weapons, depicting the MK 2 (the "good fellow") as
185:
28:
238:
high-explosive assembly was ultimately stricken from the preliminary shot schedule of operation
693:
351:
173:
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61:
44:
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952:
686:
Critical
Assembly: A Technical History of Los Alamos During the Oppenheimer Years, 1943-1945
656:
110:
491:
393:
294:
211:
52:
887:
719:
358:), powder-compacted with deuterated polyethylene. No boron was used. The cores tested in
652:
827:
48:
245:
941:
563:
290:
197:
189:
138:
32:
622:
161:) in one version, and a BeO tamper with 8.45 kg of active material in another.
857:
822:
795:
755:
660:
596:
405:
250:
222:
104:
118:
test. The explosion failed to level the testing tower, only somewhat damaging it.
379:
193:
96:
24:
400:
HE assembly made of
Composition B and Baratol explosive lenses, and an XMC-305
306:
153:
C) wax distributed uniformly throughout the solid core. A composite lead and B
363:
157:
C tamper was envisioned, with about 10.5 kg of active material (i.e. UD
36:
401:
214:
forecast that 1 kt of energy would be obtained from about 9 kg of UD
40:
568:
The Los Alamos Primer: The First
Lectures on How To Build an Atomic Bomb
334:
206:
77:
428:, the yield was still about a tenth of the predicted 0.5–1 kt value.
480:
The names of the devices all followed the initials of Small
Weapons.
921:
Operation Upshot-Knothole
Summary Report of the Technical Director
244:
109:
297:
experimented with such devices in the early 1950s at the UCRL, (
83:
Two uranium deuteride bombs are known to have been tested, the
516:
The unclassified name was "Basilisk II" as seen from
Francis,
318:
and its derivatives (like the "Swift" and "Swallow" devices).
180:) moderates (slows down) the neutrons, thereby increasing the
76:. Likewise, a "hydrogen bomb" uses deuterium and occasionally
503:
The unclassified name was "Basilisk I" as seen from
Francis,
362:
used different "mix" (or enrichment) of uranium moderated by
449:
The unclassified name was "Manticore" as seen from
Francis,
861:
799:
759:
600:
374:(with a maximum potential yield of 20 kt) and 0.5-1 kt for
683:
Hoddeson, Lillian; Paul W. Henriksen; et al. (2004).
72:), is used; only deuterium (H) has been used for the bomb
888:
Operation Upshot-Knothole 1953 - Nevada
Proving Ground
103:. All other nuclear weapons programs have relied on
678:
676:
826:
95:. Both tests produced a yield comparable to 200
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842:
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293:remained interested in the concept, and he and
188:. The result should have been a lower required
904:page 2 of archive listing of pdfs. Page 69 of
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323:University of California Radiation Laboratory
299:University of California Radiation Laboratory
8:
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396:. The explosive device, "Hydride I", used a
289:Skepticism from Los Alamos notwithstanding,
378:. The tests produced yields of about 200
558:
556:
554:
552:
540:
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536:
265:
882:
880:
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382:each; both tests were considered to be
303:Lawrence Livermore National Laboratory
7:
404:was provided for initiation through
31:in 1939 and advocated and tested by
14:
641:Bulletin of the Atomic Scientists
411:The second device, tested in the
99:each, and were considered to be
692:. Cambridge University Press.
661:10.1080/00963402.1994.11456528
1:
737:Findings to Trip to L.A. 1944
23:was a variant design of the
984:
325:designs was a preliminary
282:
126:
114:The mangled tower for the
107:in their weapons designs.
720:Operation Upshot-Knothole
635:Moore, Mike (July 1994).
545:Operation Upshot-Knothole
285:Operation Upshot–Knothole
192:; reducing the amount of
149:) and boron-10 carbide (B
93:Operation Upshot–Knothole
894:Retrieved on 2008-05-04.
722:(Nuclear Weapon Archive)
327:nucleonics investigation
892:Nuclear Weapon Archive.
829:Brotherhood of the Bomb
255:clumsy and unattractive
350:consisted of a mix of
280:
258:
119:
274:
248:
201:one destined for the
182:nuclear cross section
129:Nuclear weapon design
113:
963:Deuterated compounds
863:Swords of Armageddon
801:Swords of Armageddon
761:Swords of Armageddon
625:- globalsecurity.org
602:Swords of Armageddon
370:was 1.5 to 3 kt for
339:Mark 22 nuclear bomb
21:uranium hydride bomb
653:1994BuAtS..50d...2M
174:plutonium deuteride
133:In early phases of
57:neutron temperature
27:first suggested by
16:Type of atomic bomb
281:
259:
186:neutron absorption
120:
91:test shots during
29:Robert Oppenheimer
958:Manhattan Project
886:Carey Sublette. "
352:uranium deuteride
272:
166:uranium deuteride
164:The deuterium in
135:Manhattan Project
62:Los Alamos Primer
45:neutron moderator
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366:. The predicted
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39:, an isotope of
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866:. Vol. VII
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804:. Vol. III
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394:Mercury, Nevada
360:Upshot-Knothole
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344:Upshot-Knothole
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295:Ernest Lawrence
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53:nuclear fission
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764:. Vol. IV
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690:(Google Books)
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564:Serber, Robert
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733:Conant, James
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699:0-521-54117-4
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605:. Vol. I
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331:"Morgenstern"
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291:Edward Teller
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249:A cartoon by
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33:Edward Teller
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22:
926:. Retrieved
920:
914:
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891:
868:. Retrieved
862:
828:
817:
806:. Retrieved
800:
766:. Retrieved
760:
736:
727:
715:
705:December 15,
703:. Retrieved
685:
664:. Retrieved
644:
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637:"Lying well"
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618:
607:. Retrieved
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275:Film of the
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251:George Gamow
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212:James Conant
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88:
84:
82:
67:
60:
20:
18:
380:tons of TNT
279:detonation.
97:tons of TNT
25:atomic bomb
942:Categories
928:2019-02-17
870:2016-12-28
808:2016-12-28
768:2016-12-28
666:2010-02-07
609:2016-12-28
432:References
307:spheroidal
262:UCRL tests
240:Greenhouse
127:See also:
35:. It used
528:Citations
364:deuterium
37:deuterium
860:(1995).
825:(2003).
798:(1995).
758:(1995).
735:(1944).
647:(4): 2.
599:(1995).
566:(1992).
402:betatron
301:, later
207:inertial
51:of slow
41:hydrogen
953:Uranium
649:Bibcode
384:fizzles
335:lithium
101:fizzles
78:tritium
43:, as a
924:. 1953
696:
316:"Swan"
145:aka UH
123:Theory
437:Notes
368:yield
348:cores
221:Post-
172:) or
141:of UD
55:(see
707:2008
694:ISBN
426:Ruth
422:Ruth
417:MK-6
398:MK-6
390:Ruth
372:Ruth
277:Ruth
236:MK 4
232:MK 5
227:LANL
203:MK 3
184:for
176:(PuD
116:Ruth
87:and
85:Ruth
74:pits
19:The
890:."
657:doi
623:W48
413:Ray
376:Ray
354:(UD
223:war
196:or
168:(UD
89:Ray
944::
879:^
839:^
777:^
745:^
675:^
655:.
645:50
643:.
639:.
576:^
551:^
535:^
386:.
242:.
225:,
218:.
198:Pu
80:.
65:.
931:.
908:.
873:.
833:.
811:.
771:.
739:.
709:.
669:.
659::
651::
612:.
570:.
520:.
507:.
453:.
356:3
311:3
257:.
216:3
194:U
178:3
170:3
159:3
155:4
151:4
147:3
143:3
70:H
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