STUDY OF RADIOACTIVITY AND MEASUREMENT OF ABSORPTION COEFFICIENT OF GAMMA RAYS OF PHOTONS FOR ALANINE
Submitted toDr. Babasaheb Ambedkar Marathwada University, Aurangabad
Submitted By Mr. Haqi Esmail Shareef
Under the guidance of Dr. Pravina Pawar
Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad
CertificateThis is to certify that Mr. Haqi Esmail Shareef has successfully completed the project intitled Study of Radioactivity and Measurement Of absorption Coefficient of Gamma Rays of Photons for Alanine under the guide of Dr. K.M. Jadhav and Pravina Pawar. For partial fulfillment of requirement for a work of the degree of Master of Science in Physics with specialization Nuclear Physical in the Academics year 2011-2012.
Prof. (Dr) K.M. Jadhav (Professor Incharge)
Prof. (Dr) P.W. Khirade
Dr. Pravina Pawar (Asst. Professor)
AcknowledgmentI express my first and for most thanks and gratitude to Prof. Dr. K.M. Jadhav Sir for permitting me to undertake this project work and giving valuable guidance. He has a source of inspiration for completion and shaping of the assigned work in a proper way. If feel honored to remain indebted to him forever It is also a pleasure to express my gratitude thanks to Dr. Pravina Pawar mam, for giving a valuable guidance. Her affective concern, proper guidance, and inspiring nature naturally turned me towards the fulfillment of my project I also express thanks to my father and mother and wife and two sons who directly helped and supported me all time.
Haqi Esmail Shareef M.Sc. Physics (Nuclear Physics)
INDEXSr. No. I Chapter Name Introduction Historical Introduction Radioactivity Definition of Radioactivity Natural Radioactivity Artificial Radioactivity Units of Radioactivity Types of decay Activity measurements Mathematics of radioactive decay Universal law of radioactive decay One decay process Glossary Application of radioactivity Nuclear medicine Radiotherapy Radioactive tracers Industry and the Home Power Generation Art Restoration Fundamental Laws Of Radioactivity Radioactive decay series II Introduction to biomolecule Sr. No. 5-32 5 5-6 6 7 7 7 10 12 12 13 13 14 17 17 18 18 18 20 20 24 29 33-54
Biomolecules Importance of Biomolecules Type of Biomolecules Biomolecule - Amino - Acids Amino acid - General Structure Functional Significance of Amino Acid RGroups General Properties Peptide Bonds Classification Physical Properties Optical Properties of the Amino Acids Chemical Nature of the Amino Acids Acid-Base Properties of the Amino Acids Amino Acid Benefits Amino acids and their functions in the body III Cross section Gamma radiation Absorption coefficient of Gamma ray photons interaction of gamma ray photon with matter IV V Result & Discussion Conclusions References
33 33 34 35 38 38 39 39 40 42 45 45 48 49 50 55-69 57 59 61 88 88-89 90-91
CHAPTER - I INTRODUCTION HISTORICAL INTRODUCTIONIn attempting to discover a possible connection between X-rays and luminescence observed in a discharge tube, H. Becquerel (1895) found that after exposure to cathode rasy potassium suranyl sulfate possessed the property of affecting a photographic plate wrapped in black paper, indicating that the uranium salt was emitting a penetrating type of radiation. In the same year he made surprising discovery that uranium compounds alone, without any previous treatment, are capable of fogging a photographic plate, and so emit rays spontaneously. In addition to their photographic action, the radiations were foud, like X-rays, to be capable of ionizing the year, so that the activity of a uranium compound could be measured by the rate at which a known quantity caused the discharged of an electroscope. The emission of rays capable of producing these effects is a fundamental property of the uranium atom, as the rays are observed with various uranium salts in different valence states as well as with the element itself; further, the activity is found to be independent of the temperature or previous history of the material. The spontaneous emission of radiation of this type is now known as
Radioactivity:A study of the subject has thrown much light on the structure of matter. When examining the ionizing activity of the mineral pitchblende, one of the chief ores of uranium and consisting mainly of U 3O8 Mme. M. Curie and her husband, P Curie (1898) Noted that it had a greater activity than was expected from the uranium it contained. This result indicated the6
presence in the ore of compounds an element, or elements, even more radioactive than uranium and by using ordinary chemical methods of separation, two such substances were isolated. One of the elements was precipitated as its sulfide with bismuth sulfide; it was called polonium, in honor of Poland, the native country of Mme. Curie. The other elements separated together with barium as their sulfates, which were subsequently converted the bromides and separated by fraction crystallization. The elements, obtained as the impure bromide by M. Curie, P. Curie and G. Bemont (1898), was given the name Radium because of exceptional activity. After wards, A Debierne (1899) and F. Giesel (1901) found the new radioelement actinium in uranium minerals. In the course of a study of the penetrating power of the radiations. Rutherford (1899) Concluded that they could be divided in to two types, which he referred to as -rays and -Rays, Respectively. Shortly afterwards P Curie Founded that part of radiation was not deflected in a magnetic field, and this was shown by P. Villard to have exceptional penetrating power, these radiations were called the -rays.
Definition of Radioactivity:The phenomenon of spontaneous disintegration of an unstable atomic nucleus accompanied by emission of radiation is called radioactivity. Radioactivity was discovered by Henry Becquerel in 1896. He found that photographic plate was affected when placed near uranium salt. He concluded that the Uranium might have emitted highly entreating and invisible radiation. Later Madam Curic was confirmed the same. The substances showing this property are called radioactive substances.e.g. U, Ra, Th.7
Natural Radioactivity:The phenomenon of spontaneous emission of highly penetrating and invisible radiation from heavy element is called natural radioactivity. It is generally shown by heavy element having atomic number 83 or more than that.
Artificial Radioactivity:The process of stable nucleus into unstable radioactive nucleus by bombarding it with suitable projectile is called artificial radioactivity. It is generally shown by light element having atomic number less than 83.
Units of Radioactivity:In general, radiation is in the form of an alpha- particle (i.e., ionized helium atom having two units of positive charge and four units of mass), a beta-ray (a particle of mass equal to that of an electron and of either positive or negative charge emitted from a nucleus due to the proton or neutron decay), a gamma ray an electromagnetic radiation similar to X-rays but emanating from a nucleus) and neutrons. A radioactive material is characterized by the type of radiation it emits, the energy of the emitted radiation, and its half. Half life is the time required for reducing the number of radioactive to one-half the initial value. Some of the naturally [in the range of occurring radioisotopes have a very long half- life
thousands of years (yr), whereas some artificially produced radioisotopes have a very short half- life [ in the range of milliseconds (msec) to microseconds (sec) ] Thus it is essential that we define the activity or
disintegration rat e of a radioisotope since each disintegration emits an energetic particle which interacts with the surrounding medium. The fundamental unit of radioactivity is the curie (Ci). One curie represents 3.7 1010 disintegrations per second (dis/sec) of any type of radiation. This unit has now been replaced by an SI unit, called the Becquerel (Bq), which represents one disintegration per second. As is evident, the Becquerel is itself a small unit. The conventionally used units, smaller than the curie, are known as milicurie (mCi; 1 mCi = 10-3 Ci) and microcurie (Ci; 1Ci =10-6 Ci) Most sources handled in a laboratory are either of microcurie or, at the most, few millicurie strength. The radioisotopes used in food processing and medical therapy can be of the order of several kilocurie (kCi) or even megacurie (MCi) If N represents the number of atoms of a radioactive substance and its disintegration rate constant or decay constant (ie., probability of disintegrations per second per atom) hen the product N represents the activity of the substance. The disintegration rate constant is related to half life T as 0.693/ T1/2 since, at any time t,N(t) Noe-. Therefore, for a given N, a substance with a long half life will be less active than a substance with a short half- life. Thus, an optimal choice of weight and half life is always desirable, depending on the situation. Some of radioisotopes commonly used in the laboratory and their radiations are indicated in Fig 1.1 and Table 1.1.
Table 1.1 Some common laboratory radioactive sources (a) Gamma ray Sources Isotope137 60
Half life 30 yr 5.25 yr 2.6 yr 300d 108d
Gamma ray energy (Mev) 0.662 (93.5%) 1.173 (100%) 1.332(100%) 1.275 (100%) 0.511 (100%) 0.835 (100%) 0.898 (91%) 1.836%)
Table 1.1 Some common laboratory radioactive sources (b)Beta-ray sources ( negative) Isotope99 14 3
Half life 2.12 105 yr 5730 yr 12.26 yr 3.81 yr 2.62 yr 87.9 d 14.28d 27.7yr /64 hr
Maximum energy (Mev) 0.292 0.156 0.0186 0.766 0.224 0.167 1.71 0.56/2.27