|
_atomic bomb _
By: not known
Just before the beginning of World War II, Albert Einstein wrote a letter to
President Franklin D. Roosevelt. Urged by Hungarian-born physicists Leo
Szilard, Eugene Wingner, and Edward Teller, Einstein told Roosevelt about Nazi
German efforts to purify Uranium-235 which might be used to build an atomic
bomb. Shortly after that the United States Government began work on the
Manhattan Project. The Manhattan Project was the code name for the United
States effort to develop the atomic bomb before the Germans did. "The first
successful experiments in splitting a uranium atom had been carried out in the
autumn of 1938 at the Kaiser Wilhelm Institute in Berlin"(Groueff 9) just
after Einstein wrote his letter. So the race was on. Major General Wilhelm D.
Styer called the Manhattan Project "the most important job in the war . . . an
all-out effort to build an atomic bomb."(Groueff 5) It turned out to be the
biggest development in warfare and science's biggest development this century.
The most complicated issue to be addressed by the scientists working on the
Manhattan Project was "the production of ample amounts of 'enriched' uranium
to sustain a chain reaction."(Outlaw 2) At the time, Uranium-235 was hard to
extract. Of the Uranium ore mined, only about 1/500 th of it ended up as
Uranium metal. Of the Uranium metal, "the fissionable isotope of Uranium
(Uranium- 235) is relatively rare, occurring in Uranium at a ratio of 1 to
139."(Szasz 15) Separating the one part Uranium-235 from the 139 parts
Uranium-238 proved to be a challenge. "No ordinary chemical extraction could
separate the two isotopes. Only mechanical methods could effectively separate
U-235 from U-238."(2) Scientists at Columbia University solved this difficult
problem. A "massive enrichment laboratory/plant"(Outlaw 2) was built at Oak
Ridge, Tennessee. H. C. Urey, his associates, and colleagues at Columbia
University designed a system that "worked on the principle of gaseous
diffusion."(2) After this process was completed, "Ernest O. Lawrence (inventor
of the Cyclotron) at the University of California in Berkeley implemented a
process involving magnetic separation of the two isotopes."(2) Finally, a gas
centrifuge was used to further separate the Uranium-235 from the Uranium-238.
The Uranium-238 is forced to the bottom because it had more mass than the
Uranium-235. "In this manner uranium-235 was enriched from its normal 0.7% to
weapons grade of more than 90%."(Grolier 5) This Uranium was then transported
to "the Los Alamos, N. Mex., laboratory headed by J. Robert
Oppenheimer."(Grolier 5) "Oppenheimer was the major force behind the Manhattan
Project. He literally ran the show and saw to it that all of the great minds
working on this project made their brainstorms work. He oversaw the entire
project from its conception to its completion."(Outlaw 3) Once the purified
Uranium reached New Mexico, it was made into the components of a gun-type
atomic weapon. "Two pieces of U-235, individually not large enough to sustain
a chain reaction, were brought together rapidly in a gun barrel to form a
supercritical mass that exploded instantaneously."(Grolier 5) "It was
originally nicknamed 'Thin Man'(after Roosevelt, but later renamed 'Little
Boy' (for nobody) when technical changes shortened the proposed gun
barrel."(Szasz 25) The scientists were so confident that the gun-type atomic
bomb would work "no test was conducted, and it was first employed in military
action over Hiroshima, Japan, on Aug. 6, 1945."(Grolier 5) Before the
Uranium-235 "Little Boy" bomb had been developed to the "point of seeming
assured of success,"(Grolier 5) another bomb was proposed. The Uranium-238
that had been earlier ruled out as an option was being looked at. It could
capture a free neutron without fissioning and become Uranium-239. "But the
Uranium-239 thus produced is unstable (radioactive) and decays first to
neptunium-239 and then to plutonium-239."(Grolier 5) This proved to be useful
because the newly created plutonium-239 is fissionable and it can "be
separated from uranium by chemical techniques,"(6) which would be far simpler
than the physical processes to separate the Uranium-235 from the Uranium-238.
Once again the University of Chicago, under Enrico Fermi's direction built the
first reactor. "This led to the construction of five large reactors at
Hanford, Wash., where U-238 was irradiated with neutrons and transmuted into
plutonium."(6) The plutonium was sent to Los Alamos. The problem to overcome
in the development of the plutonium bomb was an isotope of plutonium. The
scientists feared this isotope would cause premature detonation and most of
the plutonium would blow apart before it could all fission. "To overcome this
so-called 'defect of nature, ' the plutonium had to be brought into a
supercritical mass far faster than conventional ballistics could
achieve."(Grolier 6) Physicist Seth Neddermeyer and mathematician John von
Neumann devised the theory of "implosion." A subcritical sphere of plutonium
was surrounded by chemical high-explosives. The 5,300 pounds of explosives
were all "carefully shaped as 'lenses.' When these were detonated, they
focused the blast wave so as to compress the plutonium instantly into a
supercritical mass."(Szasz 25) This was much more complex, and many people
doubted that it would work. There was a debate at Los Alamos about whether to
test the new plutonium 'implosion' bomb before it was actually dropped.
"Harvard explosives expert George B. Kistiakowsky and Oppenheimer both argued
for such a test, but initially Groves was opposed. He was afraid that if the
test failed, the precious plutonium would be scattered all across the
countryside."(Szasz 26) Brigadier General Leslie R. Groves, the man the army
placed in charge, was eventually persuaded. Hanford's plutonium production was
increasing fast enough so that a test would cause little delay in time. They
feared that if they dropped the untested plutonium bomb and it failed to work,
"the enemy would find themselves owners of a 'gift' atomic weapon."(Szasz 26)
The final agreement for the test was that the bomb would be placed in "a
gigantic, 214-ton, cylinder-shaped tank (called 'Jumbo')."(Szasz 26) If the
plutonium correctly fissioned, the tank would be vaporized. If it did not work
correctly, the conventional explosives would be contained in the tank and the
plutonium would stay in the tank. After further development of the implosion
design and fears that "Jumbo" would dramatically distort all "their
complicated instrumentation-the raison d'être for the test,"(Szasz 36) the
world's largest pressure tank was not used. On Monday, July 16, 1945, at
5:29:45 A.M., Mountain War Time, the plutonium bomb ignited at the Trinity
site, a remote site in the New Mexico desert. "The explosion created s
brilliant flash that was seen in three states."(Szasz 83) There were many
reports from civilians from all over that described the experience. People who
saw it said it looked like the sun had risen for a few minutes and then went
back down. Others thought they had seen a large plane or meteor crash. A sheep
herder who was laying sleeping on a cot fifteen miles away was blown off. "The
Smithsonian Observatory on Burro Mountain confirmed a shock but noted that the
vibrations were unlike any earthquake ever recorded."(Szasz 84) An eight
year-old boy was awakened and ran for his Methodist parents, and they
considered if this might be the end of the world. The most powerful statement
that has been cited in practically every coverage of the atomic bomb is
Georgia Green's experience. She was being driven to Albuquerque. "What was
that?" she asked her brother-in-law, who was driving. This was very unusual
because Georgia Green was blind. Brigadier General Farrell wrote a letter for
the Secretary of War. "'No man-made phenomenon of such tremendous power had
ever occurred before . . . Thirty seconds after the explosion came, first, the
air blast pressing hard against people and things, to be followed almost
immediately by the strong, sustained, awesome roar which warned of doomsday
and made us feel that we puny things were blasphemous to dare tamper with
forces heretofore reserved to the Almighty. Words are inadequate tools for the
job of acquainting those not present with the physical, mental and
psychological effects."(Groueff 355) Upon witnessing the explosion, reactions
among the bomb's creators were mixed. Their mission had been successfully
accomplished, however, they questioned whether "the equilibrium in nature had
been upset -- as if humankind had become a threat to the world it
inhabited."(Outlaw 3) Oppenheimer was ecstatic about the success of the bomb,
but quoted a fragment from Bhagavad Gita. "I am become Death, the destroyer of
worlds." Many people who were involved in the creation of the atomic bomb
signed petitions against dropping the bomb. The atomic bomb has been used
twice in warfare. The Uranium bomb nicknamed "Little Boy," which weighed over
4.5 tons, was dropped over Hiroshima on August 6, 1945. At 0815 hours the bomb
was dropped from the Enola Gay. It missed Ground Zero at 1,980 feet by only
600 feet. "At 0816 hours, in the flash of an instant, 66,000 people were
killed and 69,000 people were injured by a 10 kiloton atomic
explosion."(Outlaw 4) [See blast ranges diagram] Nagasaki fell to the same
treatment as Hiroshima on August 9, 1945. The plutonium bomb, "Fat Man," was
dropped on the city. It missed its intended target by over one and a half
miles. "Nagasaki's population dropped in one split-second from 422,000 to
383,000. 39,000 were killed, over 25,000 were injured. That blast was less
than 10 kilotons as well. Physicists who have studied the atomic explosions
conclude that the bombs utilized "only 0.1% of their respective explosive
capabilities."(Outlaw 4) Controversy still exists about dropping the two
atomic bombs on Japan. Arguments defending the Japanese claim "the atomic bomb
did not win the war in the Pacific; at best, it hastened Japanese acceptance
of a defeat that was viewed as inevitable."(Grolier 8) Other arguments state
that the United States should have warned the Japanese, or that we should have
invited them to a public demonstration. "In retrospect that U.S. use of the
atomic bomb may have been the first act of the cold war."(Grolier 8) On the
other side, advocates claimed that the invasion of the Japanese islands could
and would result in over one million military casualties plus the civilian
losses based on previous invasions of Japanese occupied islands.
============================================================================ -
Diagram for Plutonium Bomb - -------------------------------- [Gravity Bomb -
Implosion Model] -------------------------------- -* Cutaway Sections Visible
*-
============================================================================
/\ / \ *---------------------------[1] / \
_________________/______\_________________ | : ||: ~ ~ : | [2]-------* | : ||:
: | | : ||: : | | : ||: : | | : ||: : | | : ||: : | | : ||: : | | : ||: : | |
: ||: : | | : ||: : | | : ||: : | | : ||: : | |
:______||:_____________________________: |
|/_______||/______________________________\| \ ~\ | : |:| / \ |\ | : |:| / \ |
\ | :__________|:| / \ |:_\ | :__________\:| / \ |___\ |______________| / \ |
\ |~ \ / \|_______\|_________________\_/ |_____________________________| / \ /
\ / \ / _______________ \ / ___/ \___ \ /____ __/ \__ ____\
[3]_______________________________ \ ___| / __/ \ \__ \ / / \/ \ \ / /
___________ \ \ / / __/___________\__ \ \ ./ /__ ___ /=================\ ___
__\ \. [4]-------* ___||___|====|[[[[[|||||||]]]]]|====|___||___ *------[4] /
/ |=o=o=o=o=o=o=o=o=| *-------------------[5] .' / \_______ _______/ \ `. :
|___ |*| ___| : .' | \_________________ |*| _________________/ | `. : |
___________ ___ \ |*| / ___ ___________ | : : |__/ \ / \_\\*//_/ \ / \__| : :
|______________:|:____:: :::|:\ *---------[6] .'
/:|||||||||||||'`|;..:::::::::::..;|'`|||||||*|||||:\ `. [7]----------*
||||||' .:::;~|~~~___~~~|~;:::. `|||||*|| *-------[7] : |:|||||||||' .::'\
..:::::::::::.. /`::. `|||*|||||:| : : |:|||||||' .::' .:::''~~ ~~``:::. `::.
`|\*\|:| : : |:|||||' .::\ .::''\ | [9] | /``::: /::. `|||*|:| :
[8]------------*::' .::' \|_________|/ `::: `::. `|* *-----[6] `. \:||' .::'
::'\ [9] . . . [9] /::: `::. *|:/ .' : \:' :::'.::' \ . . / `::.`::: *:/ : : |
.::'.::'____\ [10] . [10] /____`::.`::.*| : : | :::~::: | . . . | :::~:::*| :
: | ::: :: [9] | . . ..:.. . . | [9] :: :::*| : : \ ::: :: | .
:\_____________________________[11] `. \`:: ::: ____| . . . |____ ::: ::'/ .'
: \:;~`::. / . [10] [10] . \ .::'~::/ : `. \:. `::. / . . . \ .::' .:/ .' :
\:. `:::/ [9] _________ [9] \:::' .:/ : `. \::. `:::. /| |\ .:::' .::/ .' :
~~\:/ `:::./ | [9] | \.:::' \:/~~ : `:=========\::. `::::... ...::::'
.::/=========:' `: ~\::./ ```:::::::::''' \.::/~ :' `. ~~~~~~\| ~~~ |/~~~~~~
.' `. \:::...:::/ .' `. ~~~~~~~~~ .' `. .' `:. .:' `::. .::' `::.. ..::'
`:::.. ..:::' `::::::... ..::::::' [12]------------------*
`:____:::::::::::____:' *-----------------[12] ```::::_____::::''' ~~~~~
============================================================================ -
Diagram Outline - --------------------- [1] - Tail Cone [2] - Stabilizing Tail
Fins [3] - Air Pressure Detonator [4] - Air Inlet Tube(s) [5] -
Altimeter/Pressure Sensors [6] - Electronic Conduits &Fusing Circuits [7] -
Lead Shield Container [8] - Neutron Deflector (U-238) [9] - Conventional
Explosive Charge(s) [10] - Plutonium (Pu-239) [11] - Receptacle for
Beryllium/Polonium mixture to facilitate atomic detonation reaction. [12] -
Fuses (inserted to arm bomb)
============================================================================
[Gravity Bomb Model] ---------------------------- -* Cutaway Sections Visible
*- /\ / \ *---------------------------[1] / \
_________________/______\_________________ | : ||: ~ ~ : | [2]-------* | : ||:
: | | : ||: : | | : ||: : | | : ||: : | | : ||: : | | : ||: : | | : ||: : | |
: ||: : | | : ||: : | | : ||: : | | : ||: : | |
:______||:_____________________________: |
|/_______||/______________________________\| \ ~\ | | / \ |\ | | / \ | \ | | /
\ | \ | | / \ |___\ |______________| / \ | \ |~ \ /
\|_______\|_________________\_/ |_____________________________| / \ /
_________________ \ / _/ \_ \ / __/ \__ \ / / \ \ /__ _/ \_ __\
[3]_______________________________ \ _| / / \ \ \ / / \/ \ \ / / ___________ \
\ | / __/___________\__ \ | | |_ ___ /=================\ ___ _| |
[4]---------* _||___|====|[[[[[[[|||]]]]]]]|====|___||_ *--------[4] | |
|-----------------| | | | | |o=o=o=o=o=o=o=o=o| *-------------------[5] | |
\_______________/ | | | |__ |: :| __| | | | \______________ |: :|
______________/ | | | | ________________\|: :|/________________ | | | |/
|::::|: :|::::| \| | [6]----------------------* |::::|: :|::::|
*---------------------[6] | | |::::|: :|::::| | | | | |::==|: :|==
*------------------------[9] | | |::__\: :/__::| | | | | |:: ~: :~ ::| | |
[7]----------------------------* \_/ ::| | | | |~\________/~\|:: ~
::|/~\________/~| | | | ||:: *-------------------------[8] |
|_/~~~~~~~~\_/|::_ _ _ _ _::|\_/~~~~~~~~\_| |
[9]--------------------------*_=_=_=_=_::| | | | | :::._______.::: | | | |
.:::| |:::.. | | | | ..:::::'| |`:::::.. | | [6]----------------*.::::::' ||
|| `::::::.*---------------[6] | | .::::::' | || || | `::::::. | | /| |
.::::::' | || || | `::::::. | | | | | .:::::' | ||
*-----------------------------[10] | | |.:::::' | || || | `:::::.| | | |
||::::' | |`. .'| | `::::|| | [11]___________________________ ``~''
__________________________[11] : | | \:: \ / ::/ | | | | | \:_________|_|\/__
__\/|_|_________:/ | | / | | | __________~___:___~__________ | | | || | | | |
|:::::::| | | | | [12] /|: | | | | |:::::::| | | | | |~~~~~ / |: | | | |
|:::::::| | | | | |----* / /|: | | | | |:::::::| *-----------------[10] | / /
|: | | | | |:::::::| | | | | | / |: | | | |
|::::*-----------------------------[13] | / /|: | | | | |:::::::| | | | | | /
/ |: | | | | `:::::::' | | | | | _/ / /:~: | | | `: ``~'' :' | | | | | / / ~..
| | |: `: :' :| | | |-*| / / : | | ::: `. .' *----------------[11] | |/ / ^
~\| \ ::::. `. .' .:::: / | | ~ /|\ | \_::::::. `. .' .::::::_/ | |_______| |
\::::::. `. .' .:::*-----------------[6] |_________\:::::.. `~.....~'
..:::::/_________| | \::::::::.......::::::::/ | | ~~~~~~~~~~~~~~~~~~~~~~~ |
`. .' `. .' `. .' `:. .:' `::. .::' `::.. ..::' `:::.. ..:::' `::::::...
..::::::' [14]------------------* `:____:::::::::::____:'
*-----------------[14] ```::::_____::::''' ~~~~~ - Diagram Outline -
--------------------- [1] - Tail Cone [2] - Stabilizing Tail Fins [3] - Air
Pressure Detonator [4] - Air Inlet Tube(s) [5] - Altimeter/Pressure Sensors
[6] - Lead Shield Container [7] - Detonating Head [8] - Conventional Explosive
Charge [9] - Packing [10] - Uranium (U-235) [Plutonium (See other diagram)]
[11] - Neutron Deflector (U-238) [12] - Telemetry Monitoring Probes [13] -
Receptacle for U-235 upon detonation to facilitate supercritical mass. [14] -
Fuses (inserted to arm bomb) === - Breakdown of the Atomic Bomb's Blast Zones
- ---------------------------------------------- . . . . . . . . [5] [4] [5] .
. . . . . . . . . [3] _ [3] . . . [2] . . . _._ . . .~ ~. . . . [4] . .[2].
[1] .[2]. . [4] . . . . . . . ~-.-~ . . . [2] . . . [3] - [3] . . . . . . ~ ~
. ~ [5] . [4] . [5] . . . . . .
============================================================================ -
Diagram Outline - --------------------- [1] Vaporization Point
------------------ Everything is vaporized by the atomic blast. 98%
fatalities. Overpress=25 psi. Wind velocity=320 mph. [2] Total Destruction
----------------- All structures above ground are destroyed. 90% fatalities.
Overpress=17 psi. Wind velocity=290 mph. [3] Severe Blast Damage
------------------- Factories and other large-scale building collapse. Severe
damage to highway bridges. Rivers sometimes flow countercurrent. 65%
fatalities, 30% injured. Overpress=9 psi. Wind velocity=260 mph. [4] Severe
Heat Damage ------------------ Everything flammable burns. People in the area
suffocate due to the fact that most available oxygen is consumed by the fires.
50% fatalities, 45% injured. Overpress=6 psi. Wind velocity=140 mph. [5]
Severe Fire &Wind Damage ------------------------- Residency structures are
severely damaged. People are blown around. 2nd and 3rd-degree burns suffered
by most survivors. 15% dead. 50% injured. Overpress=3 psi. Wind velocity=98
mph.
---------------------------------------------------------------------------- -
Blast Zone Radii - ---------------------- [3 different bomb types]
____________________________________________________________________________
______________________ ______________________ ______________________ | | | | |
| | -[10 KILOTONS]- | | -[1 MEGATON]- | | -[20 MEGATONS]- |
|----------------------| |----------------------| |----------------------| |
Airburst - 1,980 ft | | Airburst - 8,000 ft | | Airburst - 17,500 ft |
|______________________| |______________________| |______________________| | |
| | | | | [1] 0.5 miles | | [1] 2.5 miles | | [1] 8.75 miles | | [2] 1 mile |
| [2] 3.75 miles | | [2] 14 miles | | [3] 1.75 miles | | [3] 6.5 miles | | [3]
27 miles | | [4] 2.5 miles | | [4] 7.75 miles | | [4] 31 miles | | [5] 3 miles
| | [5] 10 miles | | [5] 35 miles | | | | | | | |______________________|
|______________________| |______________________|
____________________________________________________________________________
_Bibliography _
Philip Shuman United States History Fourth Period June 9, 1995 Second Semester
Term Paper Bibliography Szasz, Ferenc Morton. The Day The Sun Rose Twice.
Albuquerque: University of New Mexico Press, 1956 Grolier Electronic
Publishing, Inc. Academic American Encyclopedia. Copied from the PRODIGY
service 05/16/95 20:16 1995 Batchelder, R.C. The Irreversible Decision.
Houghton Mifflin Company Boston, The Riverside Press Cambridge, 1962 York,
Herbert Frank. The Advisors: Oppenheimer, Teller, and The Superbomb. San
Francisco: W.H. Freeman and Company, 1976 Taylor, Alan John Percivale. The
Second World War. New York: G.P. Putnam's Sons, 1975 Groueff, Stephane.
Manhattan Project. Boston: Little, Brown and Company, 1967 Outlaw Labs.
downloaded from P-80 Systems, 304-744-2253
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