Sunday, October 10, 2010

Basic of nuclear physics......

History of nuclear physics

So here...I post again about the basic of nuclear physics....hope you guys can understand a little bit of it....like me also...
@ The history of nuclear physics is

*  The discipline distinct from atomic physics starts with the discovery of radioactivity by Henri Becquerel in 1896,while investigating phosphorescence in uranium salts. The discovery of the electron by J. J. Thomson a year later was an indication that the atom had internal structure.
*  In 20th century the accepted model of the atom was J. J. Thomson's "plum pudding" model in which the atom was a large positively charged ball with small negatively charged electrons embedded inside of it. By the turn of the century physicists had also discovered three types of radiation coming from atoms, which they named alpha, beta, and gamma radiation. 


@ So,there are the best things that we must know about the nuclear physics.
Nuclear physics is the field of  
-atomic nuclei
-nuclear power
-nuclear weapons
-nuclear medicine
-magnetic resonance imaging
-material engineering
-ion implatation
-archaeology
-radiocarbon dating 


For this reason,it has been included under the same term in earlier times.
So,
@ The atoms of which every element of matter is composed have a nucleus at the center and electrons whirling about this nucleus that can be visualized as planets circling around a sun, though it is impossible to locate them precisely within the atom. 

@ The nuclei of atoms are composed of protons, which have a positive electrical charge, and neutrons, which are electrically neutral. Electrons are electrically negative and have a charge equal in magnitude to that of a proton. 

And also,
What is the Nuclear (fission) energy:
•The Commercially established since 1956 
 Calder Hall, gas-cooled Magnox NPP at Sellafield (UK), 50 MW  (later 200 MW)
• and Today: ~16% of world’s electricity generation (18% hydro, 66% fossil)
• Switzerland: ~40% (nearly all the rest: hydro)


This is about the structure of the atom (Rutherford’s model):
• Mass concentrated in the nucleus (mH/me ~ 1837)
• Nuclear charge: +Ze (Z: atomic number, e ~ 1.6.10-19 coulomb)
• Quantum mechanical basis for atomic, nuclear structure
• “Classical dimensions”: nucleus ~ 10-13 cm, atom ~ 10-8 cm


Energy units (1eV ~ 1.6.10-19 J)is the :
- Binding energy of outermost electrons ~ order of eV
– Energy involved in chemical reactions ~ same order
- Binding energy of nucleons (constituents of nucleus) ~ order of  MeV !
– Energy in nuclear reactions 106 times greater than in chemical.


This is the Often encountered in nuclear engineering:
- Nuclear fuel, activation of materials, fission products, wastes
- Fundamental law: (λ : decay constant)
- Units of (radio)activity:
- 1 curie (Ci) = 3.7 x 1010 dis/s (activity of 1 gm of Ra226)
- 1 becquerel (Bq) = 1 dis/s
- Example: 1 mCi = 10-3 Ci = 3.7 x 107 Bq = 37 MBq

7 comments:

Anonymous said...

Good post. More basics for newbies. For now only 16% of the world is using NPP as their electricity generator. Mostly Asia and those less developed countries don't have NPP in their country is because of the reason that the countries can generate enough electricity to support their people using their own methods. And basically nuclear energy generates more electricty using less quantity. We know this all because of E=mc2 created by the famous Albert Einstien.

Aplox said...

Good post. More basics for newbies. For now only 16% of the world is using NPP as their electricity generator. Mostly Asia and those less developed countries don't have NPP in their country is because of the reason that the countries can generate enough electricity to support their people using their own methods. And basically nuclear energy generates more electricty using less quantity. We know this all because of E=mc2 created by the famous Albert Einstien.


Ang Jit Yong (ME083530)
aplox3@hotmail.com

Anonymous said...

This is a knowledge worth sharing!Good post!Nyway just want to add on Ang Jit Yong's post Korea have just won NPP building contract in the united arab emirates which suprised many major countries in nuclear power such as France.Thats a good start for an Asian country! Bravo! Malaysia to one day can have their own NPP!GO MALAYSIA!

Anonymous said...

This is a knowledge worth sharing!Good post!Nyway just want to add on Ang Jit Yong's post Korea have just won NPP building contract in the united arab emirates which suprised many major countries in nuclear power such as France.Thats a good start for an Asian country! Bravo! Malaysia to one day can have their own NPP!GO MALAYSIA!

Govinderan Mageswaran
ME083544
ninemoons_firing@yahoo.com

Anonymous said...

Wow. I didn't know all this before. All i knew was marie curie found out about radiation and the basics on atomic structure history. Thanks for the info.

On another note, it is still sad to see that polluting fossil fuel power plants still dominate the power industry although it is a step up from coal power plants. Hope all the power plants will be converted to zero pollution in the near future for our dying earth.

Jan Siong Lim
ME03552
jansionglim@yahoo.com

rajan said...

Thank u very much for the post here which is very much informative about nuclear.And the history also very clear and understandable for someone who just new for this nuclear thing.With all this informative things here,its clear now that its actually safe to involve in together in nuclear things.And thank u once again for the knowledge here.


kantharrajan sandaram
me083559
rajan_9849@yahoo.com

Unknown said...

An atom consists of an extremely small, positively charged nucleus surrounded by a cloud of negatively charged electrons. Although typically the nucleus is less than one ten-thousandth the size of the atom, the nucleus contains more than 99.9% of the mass of the atom! Nuclei consist of positively charged protons and electrically neutral neutrons held together by the so-called strong or nuclear force. This force is much stronger than the familiar electrostatic force that binds the electrons to the nucleus, but its range is limited to distances on the order of a few x10-15 meters.

Muhammad Sadiq Bin Anipah
ME083602
sadiqanipah@gmail.com