Nuclear technology

Is a

Technology

Industry

Industry attributes

Parent Industry

Child Industry

Technology attributes

Related Organization

International Energy Agency

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Oecd Nuclear Energy Agency

International Atomic Energy Agency

IAEA safeguards

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World Nuclear Association

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American Nuclear Society

Implementations

Date Invented

December 2, 1942

Other attributes

Wikidata ID

Q348091

Overview

Nuclear technology encompasses any technology that utilizes nuclear reactions (changes in atomic nuclei) or the radiation they produce. Examples of industries making use of nuclear technology include:

Nuclear power
Nuclear medicine
Defense
Space exploration
Agriculture
Consumer products
Food
Industrial sectors
Transport
Environment and water resources

History

Early research & the discovery of the nucleus

The history of nuclear technology goes back to a number of key scientific discoveries in the late 19th and early 20th centuries. In 1896, Henri Becquerel announced the discovery of radioactivity to the Academy of Sciences in Paris following his studies of uranium. While the discovery of x-rays by Wilhelm Roentgen predates this discovery (1895), x-rays originate from changes in the electron structure of an atom (characteristic x-ray emission) or the rapid deceleration of electrons scattered by strong electric fields (Bremsstrahlung) not from atomic nuclei. Key work furthering the field of radioactivity was performed by Marie and Pierre Curie, discovering the radioactive elements polonium and radium through the chemical extraction of uranium from the ore. The term "radioactivity" was coined by Marie Curie in 1898. Becquerel and the Curies would go on to share the 1903 Nobel Prize for their work on radioactivity.

By studying the absorption of radioactivity by thin sheets of metal foil, Ernest Rutherford demonstrated the existence of at least two different types of radiation in 1899. These types of radiation would go on to be called alpha (absorbed by a few thousandths of a centimeter of metal foil) and beta radiation (which can pass through 100 times as much foil before being absorbed). A year later, in 1900, Paul Villard first identified a third type of radiation (gamma) after studying radium. This new type of radiation was significantly more penetrating, able to pass through several centimeters of lead. Rutherford would go on to name these three types of radiation for the first three letters of the Greek alphabet, alpha, beta, and gamma.

Further studies found the radiation behaving differently in the presence of electric and magnetic fields with alpha particles deflected more slowly than beta-particles suggesting they were lighter and gamma-rays being unaffected. Experimental results found alpha and beta particles have charges of opposite signs and gamma rays are neutral, with no electric charge. In 1902 Rutherford and Frederick Soddy proposed the idea radioactivity originates from the spontaneous transmutation of elements.

In 1907 and 1908, Rutherford worked closely with Hans Geiger researching alpha particles. They developed two methods of observing alpha particles:

The first method involved scintillations excited by α particles on a thin layer of zinc sulfide. They observed these through a microscope and counted the scintillations at different angles of dispersion.
The second method was an "electrometer" that could demonstrate the passage of an individual α particle to a large audience. The instrument, which evolved into the "Geiger counter," had a partially evacuated metal cylinder with a wire down its center. They applied a voltage between the cylinder and the wire high enough almost to spark.

Rutherford suspected as early as 1906 that α particles were helium atoms stripped of their electrons. However, he needed more evidence for his claim and was frustrated by their inability to divert alpha particles enough to measure their charge and mass more directly, a process that would have required large electromagnets unavailable to him. In the autumn of 1908, Rutherford, Geiger, and Ernest Marsden (a 19-year-old student) began a series of experiments passing beams of alpha particles through gold and other metallic foils. They used their new detection methods to measure how much the beams were dispersed by the atoms in the foils seeking mathematical relationships between dispersion and thickness of foil or the number of atoms traversed. Marsden later recalled that Rutherford asked him to try and measure backscattered radiation, alpha particles that had been directly reflected by the metal foils. After confirming the existence of backscattered alpha particles, Rutherford remarked:

I remember ...later Geiger coming to me in great excitement and saying, 'We have been able to get some of the α-particles coming backwards...' It was quite the most incredible event that has ever happened to me in my life. It was almost incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.

In May 1909, the team published their results. After dissecting the implications of the gold foil experiment Rutherford brought Marsden back to Manchester in the autumn of 1910 to test his ideas with Geiger. They re-established rates of emission, ranges of alpha particles by radioactive sources, and they re-examined their statistical analyses. Rutherford tried to reconcile scattering results with different atomic models, in particular J.J. Thomson's theory in which the positive electricity is as dispersed evenly throughout the whole sphere of the atom. During the winter of 1910-1911, Rutherford developed his basic idea of an atom with a charged center, which would later be known as the nucleus.

Below is a page from Rutherford's rough notes during the time. The first few lines read:

Theory of structure of atom. Suppose atom consists of + charge ne at centre & of – charge as electron distributed throughout sphere of radius r.

It then roughly outlines ideas about the calculation of the force of deflection on a charged particle passing close to this charged center.

Rough page of notes from Rutherford, date unknown (1910-1911).

In May 1911, Rutherford published a paper stating that such a significant deviation in the path of a charged particle could only be achieved if most of the atom's mass is concentrated in a very small central body.

Fundamental science

Nuclear Technology involves many topics from fields such as nuclear physics and radiation physics. Below is a list of topics related to the fundamental science behind nuclear technology.