r;'~i -

More documents

Recommendations

Info

DESCRIPTION OF AIR AND SURFACE BURSTS 43essentially of neutrons and gamma rays. fireball. This glow may persist for anThe relative proportions of these two appreciable length of time, being disradiationsmay be somewhat different tinctly visible near the head of the rathanfor a weapon in which all the en- dioactive cloud. It is believed to be theergy release is due to fission, but for ultimate result of a complex series ofpresent purposes the difference may be processes initiated by the action of thedisregarded.various radiations on the nitrogen andoxygen of the air.THE ELEcrROMAGNETIC PULSE 2.48 Another early phenomenonfollowing a nuclear explosion in certain2.46 If a detonation occurs at or circumstances is the formation of anear the earth's surface, the EMP phe- "condensation cloud." This is somenomenonreferred to in § 1.38 produces times called the Wilson cloud (orintense electric and magnetic fields cloud-chamber effect) because it is thewhich may extend to distances up to result of conditions analogous to thoseseveral miles, depending on the weapon utilized by scientists in the Wilson cloudyield. The close-in region near the burst chamber. It will be seen in Chapter IIIpoint is highly ionized and large electric that the passage of a high-pressurecurrents flow in the air and the ground, shock front in air is followed by a rare-producing a pulse of electromagnetic faction (or suction) wave. During theradiation. Beyond this close-in region compression (or blast) phase, the temtheelectromagnetic field stren~th, as perature of the air rises and during themeasured on (or near) the ground, drops decompression (or suction) phase itsharply and then more slowly with in- falls. For moderately low blast prescreasingdistance from the explosion. sures, the temperature can drop belowThe intense fields may damage unpro- its original, preshock value, so that iftected electrical and electronic equip- the air contains a fair amount of waterment at distances exceeding those at vapor, condensation accompanied bywhich significant air blast damage may cloud formation will occur.occur, especially for weapons of low 2.49 The condensation cloud whichyield (see Chapter XI).was observed in the ABLE Test at Bikiniin 1946 is shown in Fig. 2.49.OTHER NUCLEAR EXPLOSION Since the device was detonated justPHENOMENAabove the surface of the lagoon, the airwas nearly saturated with water vapor2.47 There are a number of inter- and the conditions were suitable for theesting phenomena associated with a nu- production of a Wilson cloud. It can beclear air burst that are worth mentioning seen from the photograph that the cloudalthough they have no connection with formed some way ahead of the fireball.the destructive or other harmful effects The reason is that the shock front mustof the explosion. Soon after the detona- travel a considerable distance before thetion, a violet-colored glow may be ob"' blast pressure has fallen sufficiently for aserved, particularly at night or in dim low temperature to be attained in thedaylight, at some distance from the subsequent decompression phase. At the
?'{ I"~ c:I~(~44 DESCRIPTIONS OF NUCLEAR EXPLOSIONS\Figure 2.4~.Condensation cloud formed in an air burst over water.Figure 2.50.Late stage of t~e condensation cloud in an air burst over water.
Page 1 and 2: CHAPTER IIDESCRIPTIONS OF NUCLEAR E
Page 3 and 4: 28 DESCRIPTIONS OF NUCLEAR EXPLOSIO
Page 5: 30 DESCRIPTIONS OF NUCLEAR EXPLOSIO
Page 8 and 9: DESCRIPTION OF AIR AND SURFACE BURS
Page 10 and 11: =-Figure 2.18b.Formation of dirt cl
Page 20 and 21: DESCRIPTION OF HIGH-ALTITUDE BURSTS
Page 22 and 23: DESCRIPTION OF HIGH-ALTITUDE BURSTS
Page 24 and 25: DESCRIPTION OF UNDERWATER BURSTS 49
Page 34 and 35: DESCRIPTION OF UNDERGROUND BURSTS 5
Page 36: DESCRIPTION OF UNDERGROUND BURSTS 6
Page 45 and 46: 70 DESCRIPTIONS =~REXPLOSIOthe shoc
Page 49 and 50: 'l"!"i --74 DESCRIPTIONS OF NUCLEAR

r;'~i -

Create successful ePaper yourself

Delete template?

Save as template?