The Innovation of physics, Nuclear Physics.

Xavier Ortiz Olavarria

A tiny thing can change the world. How it transform it into something bigger than we thought. One of the significance journeys of life is about how the discovery of the atom turns and it importance. The nucleus took part of it. Someone’s calls it the heart of matter. In reference of Bohr-Rutherford model of the atom tells that electrons surround the central nucleus and it is organize by orbits. About that, it contains two main particles that are so fundamentals in chemistry and physics. These are protons and nucleus.

That is were the journey begins, in how talented scientist like Hendrik Lorentz and Pieter Zeeman started the Nuclear physics. It began one century ago, on the famous “miraculous decade”, between 1895 and 1905. In these years all-modern physics were established and practiced. Many events occurred and transform the Nuclear physics on what it is today. According to what say Jean-Louis Basdevant in his book “Fundamentals
In Nuclear Physics”, (2005, page III-V), “the period started with two unexpected spinoffs of the Crooke’s vacuum tube: Roentgen’s X-rays (1895) and Thomson’s electron (1897), the first elementary particle to be discovered. Lorentz and Zeemann developed the theory of the electron and the influence of magnetism on radiation. For nuclear physics, the critical discovery was that of radioactivity by Becquerel in 1896.”

Talented scientists, the Curies, Rutherford, Einstein, and many others, study the principles, observe and contributed in the innovation of radioactivity and constructed the ideas of what are todays Nuclear physics. Of course, the discovery of radioactivity it is much broader importance. Basdevant, as stated in his book, “it leads directly to quantum mechanics via Rutherford’s planetary atomic model and Bohr’s interpretation of the hydrogen spectrum. Nuclear physics has transformed astronomy from the study of planetary trajectories into the astrophysical study of stellar interiors.”

In Nuclear physic, tells that the nuclei can break into certain ways and reflecting the forces. This breakup occurs by the emission of certain cases, can be both or one particle. These particles are: β particles, and γrays. They are very energetic particles of light, and also can be electromagnetic waves, or rays, nevertheless. There are three types of emitted particles: Alpha (α), Beta (β), and Gamma (γ). The fun fact is that these particles can easily be distinguished by the way they are (or are not) deflected by a magnetic field. These decays occur in different types of nuclei, as follows: “Gamma decay occurs in nuclear isomers that have too much energy, Alpha decay occurs in nuclei that have too many protons. Beta decay occurs when a neutron decays into a proton, an electron (α, and β particle), and an antineutrino.” (Burcham, W.E. in Nuclear Physics, 1973, pages 3-7) 

In Physics Todays published an article: “1932, a watershed year in nuclear physics”, that also explain how amazing the Nuclear Physics became, and it importance in our days. In 1935, Chadwick received the Nobel Prize in Physics “for the discovery of the neutron” and how he does it. With the alpha particles, he used one element radiation, Beryllium. “From the alpha-bombarded Beryllium target could only be neutral particles with mass close to that of the proton. He had discovered the neutron, liberated on the reaction.” (Physics Todays, 2013) Later, two events released a big step in Nuclear Physic. The First was in 1936, when Carl David Anderson “was observing cosmic rays with a cloud chamber mounted vertically inside a magnetic field. Bisecting the chamber was a horizontal lead plate. From the curvatures and track lengths of cosmic-ray trajectories passing through the plate, Anderson concluded that about a dozen of them, collected over several months, represented positively charged electrons, which he called positrons.” (Physics Todays, 2013) The second was when Otto Hahn and Fritz Strassmann irradiated uranium with neutrons in Berlin, 1938, and they had produced nuclei with about half of uranium’s mass. An important event, because of that they discovered the nuclear fission.

Although Heisenberg suggested that nuclei would then consist only of nucleons. He proposed that the freedom of movement in the nucleon could individualize protons from neutrons, later named “isotopic spin or isospin. The Isospin remains an important organizing principle of nuclear and particle physics.

The deuterium nucleus, called the deuteron, became part of these events. “In 1934 Rutherford and Mark Oliphant bombarded deuterons with neutrons and thus created tritium, the third hydrogen isotope. It decays to 3He plus an electron with a half-life of 12 years.” (Physics Todays, 2013) This discovered helped at todays Nuclear Physics, because tritium is produced in the nuclear reactors, “in the heavy water used to slow down (moderate) the reactor neutrons. And tritium will have a key role in the fusion reactors of the future. It’s also the principal reaction in thermonuclear weapons.” (see the article by Joseph Reader and Charles W. Clark in Physics Today, March 2013, page 44). 

Nuclear physic you can see it in many campuses of physics. For example, applied antimatter (is a part of the applications of “PET scanning” is the detection of brain cancer and also help researchers study metabolic activity under various circumstances in different parts of the healthy brain.), nuclear reactor (for source energy), nuclear weapons, and astrophysics. The Nuclear Physic came to change our world and our perspective. It took time to be one of the greatest inventions, and is our better weapon to grow up. Only if is used wisely and for goodness.

References:

http://www.physicstoday.org/resource/1/phtoad/v66/i3/p44_s1?bypassSSO=1

http://www.stfc.ac.uk/Our+Research/4593.aspx

http://science.energy.gov/np/

http://gendocs.ru/docs/9/8570/conv_1/file1.pdf

W.E. Burcham Nuclear Physics 2nd.ed. Longman Group 1973 

http://archive.org/details/NuclearPhysics

http://www.cbs.nl/en-GB/menu/themas/macro-economie/publicaties/artikelen/archief/2009/2009-2716-wm.htm