Name: Eslam Osama Makram
ID: 135380
Group: A 1
The importance of nuclear physics in the society development
I. Introduction:
Society supports fundamental research in the expectation of benefits that support national priorities. These benefits take many forms. Satisfying natural human curiosity about the workings of nature is one, and this is the principal motivation for most researchers. Their search for new knowledge often stimulates advances in the limits of technology. It leads to instrumentation and theoretical concepts that address problems of societal concern, and to advances in other areas of science. The concepts and techniques of nuclear physics have had exceptional impact in this regard. An equally important aspect is the contribution nuclear physics makes to the education of the technically sophisticated workforce that is essential for the nation's present and future economic well-being. Graduate education in nuclear physics provides broad training, involving experimental and conceptual techniques from a broad range of science and technology. As a result, nuclear physicists contribute in many areas of our society, frequently well beyond their original training in nuclear physics. Nuclear physics laboratories also provide an infrastructure for the hands-on education of younger students, involving undergraduates in research and exposing secondary school teachers and their students to the subatomic world and to scientific research. The direct applications of nuclear physics have a major overlap with the priorities of the nation: improvements in human health, the environment, the efficiency of industrial processes, energy production, the exploration of space, and national security. Beyond these direct applications is the general benefit that arises from pressing forward the frontiers of high-technology development.
II. Discussion:
Nuclear Physics is the study of the heavy but tiny nucleus that lies at the center of all atoms and makes up 99.9% by mass of everything we see. The nucleus forms a fascinating laboratory for study, falling between the extremes of systems with a handful of particles, which can be solved from first principles, and systems with thousands of particles whose properties can be treated statistically. Indeed, the nucleus is a unique microscopic quintal system that is composed of two types of interacting fermions in which the underlying force is poorly understood. As such it provides an extremely important testing ground for models that attempt to predict the properties of nuclei. The individual protons and neutrons in the nucleus can strongly dictate the properties of the nucleus as a whole. Although a mature field, nuclear physics poses an array of very challenging questions and the recent advent of accelerated radioactive beams has reinvigorated this research area. Increasingly important is the application of our understanding of nuclear physics to astrophysical questions, where it can help to understand energy generation in stars as well as the heavy elements synthesized in stellar explosions.
‘ Some of the most pervasive applications of nuclear physics are in medicine. Medical imaging techniques now widely used, such as positron emission tomography (PET) and nuclear magnetic resonance imaging (MRI), provide information in three dimensions about the structure and biochemical activity of the human interior. Radioactive isotopes produced by accelerators and reactors are routinely used in medical diagnostic procedures, in treatment, and in medical research. Cancer radiation therapy mainly uses electron accelerators and radioactive sources. Treatment with protons, neutrons, and heavier ions is becoming more widespread and shows great promise for improved selectivity and effectiveness.
‘ Many applications to environmental problems take advantage of the exceptional sensitivity of nuclear techniques such as accelerator mass spectroscopy to obtain information not available by other means. One can determine oceanic circulation patterns, the rate of carbon dioxide exchange between the atmosphere and the land and oceans, and the historic climate record. All of these have major implications for an understanding of climatic change. Studies of groundwater resources and their recharge rates, and of the origin of atmospheric pollutants, also provide unique information.
‘ The assortment of industrial applications reflects the great variety of industrial processes. One common theme is the use of nuclear techniques and accelerators to determine the composition and properties of materials, their structural integrity after manufacture, and their wear in use. Another is the development of techniques for the modification of materials through accelerator ion-implantation, as in the doping of microelectronic circuits, or the introduction of defects to increase the current-carrying properties of high-temperature superconductors.
‘ Nuclear physics continues to have a profound impact on the production of energy: nuclear fission reactors produce about 19 percent of U.S. electricity (17 percent worldwide), and they provide an option for reducing use of finite hydrocarbon fuels and hence the emission of carbon dioxide into the atmosphere
3. Applications:
A few examples’of successes, of programs in early stages of development, and of some others with a good chance to become important in the future’are given here in a lot of directions like (Health ‘ environment ‘industry ‘ energy).
‘ Health
Cancer Therapy with Protons
The use of protons for radiation therapy has the advantages that protons deposit more of their energy where they stop, not where they enter the body, and that their depth of penetration can be precisely controlled so that they stop within the tumor. This allows radiologists to increase the radiation dose to the tumor while reducing the dose to healthy tissues. Over 20,000 patients have been treated with protons, mostly at accelerators originally built for physics research. Now, physicists are designing accelerators optimized for cancer therapy; one has been in operation since 1990 at Loma Linda Hospital near Los Angeles, and many others are in various stages of planning and construction, both in the United States and overseas.
‘ Environment
Accelerator mass spectrometry is also an important tool for environmental measurements. Measurements that would otherwise be difficult or impossible are made routine by its great sensitivity. One important example is the use of long-lived radioactive nuclei to obtain information about past and present climate. And measured concentrations of oxygen isotopes in Greenland ice cores show that large changes were common near the end of the last ice age. Dating of organic glacial remains in New Zealand using 14C indicates that these large changes were global in nature.
‘ Industry
Nuclear Analysis and Testing
Testing with Neutron Beams Following capture of a neutron, nuclei emit gamma rays that are characteristic of the nucleus. It is possible to produce copious beams of neutrons by using low-energy nuclear reactions, such as the deuteron plus triton reaction, bombard an unknown sample with the neutrons, and detect the presence of specific materials tagged by their characteristic gamma rays. The known dependence of total interaction probabilities on material provides another possible tag. Airport safety devices may use these techniques to check for the presence of nitrogen in otherwise undetectable plastic explosives. Neutron techniques have been especially refined for oil-well logging and are widely used for this purpose. The neutron generators must be compact, and the instruments must be able to withstand pressures as high as 2,000 times atmospheric pressure and temperatures up to 175 ”C.
‘ Energy
Large amounts of energy can be released by splitting or fissioning heavy nuclei, such as uranium, or by fusing light nuclei, such as the isotopes of hydrogen. For example, a very large fission power plant producing a billion watts of electrical power will consume only a ton of uranium in a year. In the 1960s and 1970s, a large number of nuclear fission reactors were constructed to take advantage of this energy source; at present about 110 U.S. reactors are in operation. In 1996, nuclear energy provided about 19 percent of the nation's electric power production. That share has grown continuously, without construction of new plants, because the reliability of nuclear reactors has improved to 76 percent in 1996. Several states obtained more than 50 percent of their electric power from fission in 1996. Internationally, France obtains the highest fraction of its electricity, 77 percent, from nuclear reactors.
4. Critical assessment:
Nuclear physics, which involves the most fundamental aspects of nature and is not directly focused on societal issues. If one examines the contributions outlined above, three threads running through them can explain this result. First, the techniques of nuclear physics are relevant to many of our national problems. Second, the broad training and team experience of many students in nuclear physics provide the background that allows them to confidently and fruitfully apply nuclear techniques in many settings. And third, the varied properties of nuclei, and their radiations, lend themselves to the remarkably broad range of specific applications discussed in this chapter.
5. Conclusion:
From the moment we get up in the morning, until we go to sleep, we benefit unknowingly from many ingenious applications of radioisotopes and radiation. The water we wash with (origin, supply assurance), the textiles we wear (manufacture control gauging), the breakfast we eat (improved grains, water analysis), our transport to work (thickness gauges for checking steels and coatings on vehicles and assessing the effects of corrosion and wear on motor engines), the bridges we cross (neutron radiography), the paper we use (gauging, mixing during production processes), the drugs we take (analysis) not to mention medical tests (radioimmunoassay, perhaps radiopharmaceuticals), or the environment which radioisotope techniques help to keep clean, are all examples that we sometimes take for granted.
6. References:
[1] ‘Long Range Plan’ of the Nuclear Science Advisory Committee (USA, 1996).
[2] ‘Columbus’ White Paper (USA, 1997).
[3] ISAC-I Proposal (Canada, 1993).
[4] ‘Nuclear Physics in Europe: Highlights and Opportunities’, Report from the Nuclear Physics European Collaboration Committee (Europe, 1997).
[5] Sojourner’. Mars Rover’, and spacecraft design and images copyright ” 1996-97, California Institute of Technology
[6] W.S. Broecker. Scientific American. Nov. 1995. Page 62. Copyright ” 1995 by Scientific American. Inc.
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