Yellow Sun was the first British operational high-yield strategic nuclear weapon warhead. The name refers only to the outer casing; the warhead (or physics package) was known as "Green Grass" in Yellow Sun Mk.1 and " Red Snow " (a US design) in Yellow Sun Mk.2.
30-425: (Redirected from Yellow Sun ) Yellow sun or Yellow Sun may refer to: Yellow Sun (nuclear weapon) , a British nuclear weapon Yellow sun, a type of stellar classification "Yellow Sun", a song by The Raconteurs from their album Broken Boy Soldiers Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
60-583: A Mk.2. Green Grass was of similar layout to Green Bamboo, although it was not thermonuclear, being a very large unboosted pure fission warhead that was based in part on the core of the Orange Herald device tested at Grapple , with some of the implosion and firing features of Green Bamboo. The modulated neutron initiator was Blue Stone . Twelve Green Grass warheads were fitted in the much larger, older casings derived from Blue Danube and known as " Violet Club ". These twelve warheads were later transferred to
90-432: A competing idea of alternating layers of deuterium and uranium-238 around a fissile core (Sakharov's 'first idea'). This second design was code named Sloika (RDS-6s) or 'Layer Cake' after the layering. In March 1949 Vitaly Ginzburg proposed to replace the deuterium by lithium-6 deuteride ('second idea'). The proposal was based on the better efficiency due to the generation of tritium by the neutron capture of lithium and
120-515: A force equivalent to 400 kilotons of TNT . RDS-6 utilized a scheme in which fission and fusion fuel ( lithium-6 deuteride ) were " layered ", a design known as the Sloika (Russian: Слойка , named after a type of layered puff pastry ) or the so-called layer cake design, model in the Soviet Union. A ten-fold increase in explosive power was achieved by a combination of fusion and fission, yet it
150-563: Is on display at the Air Force Museum in Cosford, England. RDS-6s RDS-6s ( Russian : РДС-6с , from the Soviet codename for their atomic bombs Russian : Р еактивный Д вигатель С пециальный , lit. 'special jet engine'; American codename: Joe 4 ) was the first Soviet attempted test of a thermonuclear weapon that occurred on August 12, 1953, that detonated with
180-592: The US Mk-28 nuclear bomb . This was anglicised to adapt it to British engineering practices, and manufactured in Britain using British fissile materials. For further information see the "Deployment" section below. Deployment started in 1959–60. The RAF Service designations were Bomb, Aircraft HE 7000 lb HC Mk.1 or Bomb, Aircraft HE 7000 lb HC Mk.2 . Yellow Sun Mk.1 was intended as an "emergency" weapon, and had not been engineered for reliable long-term stockpiling. It
210-699: The 'first' and 'second' idea were used in the RDS-6s. The result was similar to the US 'Alarm Clock', but there is no indication that the Soviets were aware of the concept of the 'Alarm Clock'. After the United States tested Ivy Mike in November 1952, Lavrentiy Beria sent a memo to spare no effort on the development of the RDS-6s. In the final development report from June 1953 the yield was estimated at 300 +/- 100 kilotons. The RDS-6s
240-568: The Green Granite design became available. To produce the required yield, the implosion of the fissile core had to be extremely uniform. This required a complex 72-point explosive system, and led to a very large weapon overall. The resulting 45-inch (110 cm) diameter of Green Bamboo determined the 48 in (120 cm) diameter of both Yellow Sun and the Blue Steel missile . The launch of Sputnik 1 coincided with ongoing negotiations between
270-533: The RDS-27 but reduced the yield from 400 kilotons to 250 kilotons. The RDS-27 was intended as a warhead for the R-7 ICBM. The RDS-27 was tested November 6, 1955 (Joe 18). Despite the inability of the RDS-6s to be scaled into the megaton range, the detonation was still used by Soviet diplomats as leverage. The Soviets claimed that they too had a hydrogen bomb, but unlike the United States' first thermonuclear device, theirs
300-468: The RDS-6t was also stopped after it was proven that thermonuclear ignition was not possible in the RDS-6t. Both the RDS-6s and the RDS-6t were dead ends and research focused again on a two-stage thermonuclear weapon. A variant of the RDS-6s was developed later, code named RDS-27. The difference between the RDS-6s and the RDS-27 was that the RDS-27 did not use tritium. This improved the operational usefulness of
330-522: The RDS-6t was similar to this classical super. The difference was that the light shell of beryllium oxide was replaced by a heavy shell. The assumption was that the deuterium tritium mixture could be easily heated and compressed, and the shock would start the thermonuclear reaction prematurely. A heavy shell opaque to radiation would prevent this unwanted preheating more than the light shell. In September-October 1948 Andrei Sakharov , working in FIAN, came up with
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#1733093630871360-628: The US W-28 warhead used in the US Mark 28 nuclear bomb . This was anglicised to adapt it to British engineering practices, and manufactured in Britain using British fissile materials and known as Red Snow. Red Snow was more powerful, lighter and smaller than Green Grass. It was always envisaged that the Yellow Sun bomb casing would be adapted for successor warheads to minimise unessential development time and cost. Yellow Sun Mk. 2 entered service in 1961, and remained
390-593: The US and UK about nuclear technology, and the sudden shock of an apparent Soviet superiority swept aside lingering US concerns about the UK after the Suez Crisis . These negotiations would lead to the US–UK Mutual Defence Agreement in 1958. With access to US designs, the original plan to use Green Granite for Stage 2 was abandoned as a new thermonuclear warhead would be available before Granite would be. This meant
420-605: The Yellow Sun Mk.1 casings and supplemented by further warheads totalling 37. Green Grass yield was originally stated to the Royal Air Force (RAF) as 500 kilotons of TNT equivalent (2.1 PJ ), but the designers' estimate was later revised downwards to 400 kt of TNT. The Green Grass warhead was never tested. It used a dangerously large quantity of fissile material – thought to be in excess of 70 kilograms (150 lb), and considerably more than an uncompressed critical mass . It
450-412: The electrical power generating and airburst fuze. Unlike contemporary United States bombs of similar destructive power, Yellow Sun did not deploy a parachute to retard its fall. Instead, it had a completely flat nose which induced drag, thereby slowing the fall of the weapon sufficiently to permit the bomber to escape the danger zone. Additionally, the blunt nose ensured that Yellow Sun did not encounter
480-690: The massive Blue Danube over the next year. Mark 2 with Red Snow began to replace it in 1961. Beginning in 1966, Yellow Sun was replaced by the WE.177 , based on another US design. The casing was around 21 feet (6.4 m) long, and 48 inches (1.2 m) in diameter. The Mark 1 version with the Green Grass warhead weighed 7,250 pounds (3,290 kg). The Mk.2 version with the lighter 1,700 pounds (770 kg). The Red Snow warhead had ballast added to maintain overall weight, ballistic and aerodynamic properties, and avoid further lengthy and expensive testing, and changes to
510-464: The need for a powerful interim design to fill this time period was also considerably less important. The decision was made to cancel Green Bamboo and replace it with a simpler concept. After Green Bamboo was abandoned a decision was made to use the Interim Megaton Weapon known as Green Grass in the Yellow Sun casing and designate it as Yellow Sun Mk.1 until better warheads were available for
540-535: The original designations. Stage 1 was intended as an interim design to carry a one megaton Green Bamboo warhead of the "layer-cake" type thought similar to the Soviet Sloika and the US Alarm Clock concepts. These hybrid designs are not now regarded as truly thermonuclear , but were then thought to be a stepping-stone on the route to a fusion bomb. Stage 2 was to follow when a true thermonuclear warhead based on
570-568: The primary air-dropped strategic weapon until replaced with WE.177B in 1966. Although the first British designed thermonuclear weapon to be deployed, Yellow Sun was not the first to be deployed with the RAF. US Mk-28 and Mk-43 thermonuclear bombs and others had been supplied to the RAF for use in V bombers prior to the deployment of Yellow Sun. Some bombers of the V-force only ever used American weapons supplied under dual-key arrangements. An authentic shell
600-476: The title Yellow sun . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Yellow_sun&oldid=850203471 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Yellow Sun (nuclear weapon) Yellow Sun
630-469: The transonic/supersonic shock waves which had caused many difficulties with barometric fuzing gates which had plagued an earlier weapon, Blue Danube . Electrical power was supplied by duplicated ram-air turbines located behind the twin air intakes in the flat nose. The earlier Blue Danube design had relied on lead–acid batteries which had proven to be both unreliable and to require time-consuming pre-flight warming. Yellow Sun Stage 1 and Stage 2 were
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#1733093630871660-415: The uranium-238 fission by the 14 MeV neutrons from D + T fusion. At that time Ginzburg did not know that the cross section for D + T reaction was much larger than that for D + D reaction. In April 1949 the group received D + T cross section data obtained from intelligence gathering without mentioning the source. The large advantage of lithium deuteride became evident and the deuterium design was abandoned. Both
690-496: Was always envisaged that a Mk.2 version would be available later fitted with a true thermonuclear warhead derived from the Granite type tested at Grapple, or an American type made available after the 1958 US-UK Mutual Defence Agreement . It was carried only by RAF V bombers . In September 1958 a decision was made to abandon the Granite type warheads intended for Yellow Sun Mk.2 (and Blue Steel, and Blue Streak MRBM ) and instead adopt
720-453: Was deployable by air. The Soviet claim did not fool the American scientists: their fallout analysis demonstrated to them that the Soviet device was similar to Teller's Alarm Clock concept. The United States didn't develop a deployable version of the hydrogen bomb until five months after the RDS-6s test, in 1954. The first Soviet test of a "true" hydrogen bomb was on November 22, 1955, under
750-417: Was designed to contain a variety of warheads. The initial plan was that it would carry an alarm-clock-type warhead known as " Green Bamboo ", and then replace it with a true thermonuclear warhead known as "Green Granite". After signing a weapon technology agreement with the US, both concepts were dropped. Green Granite would be replaced by Red Snow at an earlier service date. This meant the interim Green Bamboo
780-472: Was kept subcritical by being fashioned into a thin-walled spherical shell. To guard against the accidental crushing of the core into a critical condition, the shell was filled with 133,000 steel ball-bearings, weighing 450 kilograms (990 lb). In a conflict, these would have had to be removed before flight. The RAF thought it unsafe (see Violet Club § Controversy ). Red Snow was the US W28 warhead used in
810-538: Was less important and it was replaced by the less powerful and simpler " Green Grass ". A unique feature of the Yellow Sun casing was its completely flat nose. This provided two benefits, one was that the drag allowed the bomb to fall behind the bomber a safe distance before detonation, and the other was that it did not generate the complex pattern of shock waves that a classically curved nose created, which made it difficult to measure altitude barometrically. Mark 1 with Green Grass began to enter service in 1959, replacing
840-548: Was still 26 times less powerful than the Ivy Mike device tested by the US in 1952. A similar design was earlier theorized by Edward Teller , but never tested by the US, as the " Alarm Clock ". The Soviet Union started studies of advanced nuclear bombs and a hydrogen bomb, code named RDS-6, in June 1948. The studies would be done by KB-11 (usually referred to as Arzamas-16 , the name of the town) and FIAN . The first hydrogen bomb design
870-406: Was tested on August 12, 1953 (Joe 4). The measured yield was 400 kilotons, 10% from fission of the uranium-235 core, 15-20% from fusion and 70 - 75% from fission of the uranium-238 layers. After the successful test Sakharov proposed a more powerful version of the RDS-6s, code named RDS-6sD. Attempts to increase the yield of the RDS-6s however proved unfeasible. In December 1953, all research on
900-496: Was the Truba ( Russian : Труба , pipe/cylinder) (RDS-6t)). In March 1948 Klaus Fuchs had provided the USSR with documents of the US 'Classical Super' . In these documents the classical super was described as consisting of a gun-type uranium-235 primary with beryllium oxide tamper and a secondary consisting of a long cylinder with deuterium, doped with tritium near the primary. The design of
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