History of Nuclear Science and Abstract

The Institute of Nuclear Sciences was established in 1982 to provide graduate education in the field of Nuclear Sciences. According to the order of establishment of the Institute, it consists of the Department of Radiation Physics and Applications and the Department of Photonics. However, nuclear sciences is a branch of science that covers the basic science fields of nuclear physics, quantum physics, atomic physics and nucleus, radiation, as well as the applied studies of these fields. The application areas of nuclear science are quantum optics, quantum photonics, medical physics, nuclear photonics, nuclear engineering and radiation protection, each with its own details.

Atomic physics and nuclear physics (physics of the atomic nucleus, nuclear physics for short) are the first fields of study of nuclear sciences from a historical and categorical perspective. If we give a general description, we can say that it is a very broad field of study. It encompasses the study of elementary particles such as electrons, protons and neutrons[1], their structures and properties, and the behavior of the atom as a system together with electrons and the nucleus (Eng: nucleus, plural "nuclei"). In the context of these studies, atomic physics is the study of the atom as a whole system, while nuclear physics is concerned with the atomic nucleus itself and the protons and neutrons that make up the nucleus and their interactions in the atomic nucleus. Electron microscopy and lasers are topics within the scope of atomic physics. However, if we make a complementary distinction, atomic physics is the study of the energy range in the Electron Volt (eV) scale, while nuclear physics is the study of the energy range up to billion eV (GeV). For this reason, it can overlap with Particle Physics, which branched out later.

Radiation physics and its applications is a field of study that has developed together with the fields of atomic and nuclear physics since the 1890s. We can use the definition given by Wikipedia (https://en.wikipedia.org/wiki/Radiation) for radiation here: Radiation is the propagation or transmission of energy as waves or particles in space or in a material medium. Particle radiation includes alpha and beta radiation, wave radiation includes a spectrum from x-rays and gamma rays to visible region and radio waves, in short, they are within the electromagnetic wave spectrum. If we define radiation on the energy scale, we must divide it into ionizing and non-ionizing radiation. Ionization is the detachment of electrons from atoms and is therefore a very dangerous situation for living things as it causes chemical bonds to break. Radiation that does not cause ionization, on the other hand, as the previous sentence suggests, is radiation whose energy is not sufficient to break electrons from atoms. However, they can be harmful due to their thermal effects when exposed for a long time. Discussions about mobile phones and base stations causing cancer are due to their long-term focused thermal effects. For example, talking on a mobile phone for several hours may cause a temperature increase in the surrounding tissue. Harmful effects are the subject of research. Infrared (infrared) and ultraviolet (ultraviolet) rays (and lasers that emit these rays) do not cause ionization but have a caustic effect on the tissue they focus on. For this reason, we include laser radiation in the study of radiation physics (health physics) and medical physics in the context of radiation protection and the possible damage of the energy transferred to the tissue.

Quantum physics and quantum mechanics are intertwined fields, sometimes describing the same thing. To clarify the difference between the work in these two fundamental fields of science, we can define quantum physics as the most fundamental field of study concerning the essence of matter and energy.

The properties and behaviors of the most basic building blocks of nature are the domain of quantum physics. It covers quantum mechanics and quantum field theory. In this context, quantum mechanics deals with the states of matter and energy depending on the conditions, in other words, their behavior. Particle interactions and motions are the subject of quantum mechanics.

Quantum optics is the part of optics that deals with quantum effects. For example, this includes the study of the properties of atomic nuclei and excitation energy level transitions using laser techniques. Extremely high intensity x-ray and gamma-ray lasers are used to sufficiently excite atomic nuclei. The construction of miniaturized photonic circuits and the detection of spatial separation on a scale that has not been achieved before are being attempted.

Photon is derived from the Greek word "photo" meaning "light". Photon is a designation meaning "quantum (quanta) of light". Although the origin of the term is directly related to light, today we call "photon" energy packets that carry wave characteristics at a certain frequency. An electromagnetic wave at a certain periodic frequency is called a photon. Photonics includes photon information transfer applications, photon beam generation, deflection, modulation, amplification, image processing, storage and detection. In this respect, it is defined by analogy with the field of electronics.

Nuclear photonics is the name given to the development of new generation gamma ray sources based on both conventional and laser-plasma electron accelerators, and the initiation of nuclear interactions with laser technology.

Quantum photonics is the science and technology that uses quantum optics for specific applications, such as quantum communications, quantum cryptology, quantum computing, quantum teleportation, where quantum effects play an important role. Quantum photonics applications include the sensing, generation and manipulation of light and matter with quantum-level control, usually involving single photons.

[1] Here we distinguish between fundamental and elementary particles. The electron, proton and neutron are elementary particles. For example, the electron is classified as an elementary particle because it is composed of Weyl fermions. Like electrons, "muon" and "tau" particles are also elementary particles. The building blocks of protons and neutrons consist of elementary particles called quarks. An elementary particle is not made up of other particles. Quarks, neutrinos and fermions, which have not yet been observed but there is some scientific evidence for their existence, are elementary particles. The reason why we write them in the plural is because they are different from each other.

A Brief History of Nuclear Science

While summarizing the areas covered by the Institute of Nuclear Sciences in the light of a brief history below, it is first necessary to mention two Turkish scientists who have contributed to the development of this field in the international arena. Feza Gürsey is a distinguished scientist whose other works, especially the events whose image in the mirror is not the same as his own, have earned him a place in the history of international science. Erdal İnönü's theory of the İnönü-Wigner contraction, also known by his name, has once again inscribed his name in the history of nuclear science.

Based on the indivisible meaning of the word atom in Greek, it would be wrong to say that nuclear sciences began in the age of philosophers. However, in accordance with the word "science", we can consider the discovery of uranium by the German chemist Martin Klaproth in 1789 as a turning point for nuclear sciences. However, the discovery of the smallest part of matter, from its intellectual to its scientific dimension, based on observation and experimentation, began with the first findings of the British scientist Dalton in 1808 from the chemical reactions known at that time. Dalton's and later the Russian scientist Menedeleev's work in the 1860s aimed at identifying the basic elements, but it was still too early to travel to atomic dimensions.

In 1895, Wilhelm Conrad Röntgen's discovery of x-rays, which are emitted when the orbits of electrons orbiting the nucleus of an atom change from one orbit to another due to an excitation, was the first step towards the study of nuclear radiation. The period from then until 1945 was the most important years in the discovery of the atomic and subatomic world.

Einstein's theory of mass-energy equivalence, summarized by E=mc2, led scientists to the discovery of the Higgs boson, the source of the existence of mass, through experiments at the hadron collider, the world's most costly accelerator, at the CERN science center in Switzerland.

While the transformation of mass into energy at speeds close to the speed of light was proved, the transformation of energy into mass was observed in C. D. Anderson's experiment in 1932 with the formation of an electron-positron pair from gamma photon energy. Interactions in the quantum field under very high temperatures also trigger the Higgs mechanism, leading to the emergence of mass.

In this context, scientific studies to understand the structure of the atomic nucleus under the title of nuclear physics, energy production from the atomic nucleus and radiation interaction caused by excitation in the subatomic world are within the scope of the Institute of Nuclear Sciences.