We know more or less what electron, proton and neutron are, but have you ever heard of the positron? Considered as the first important example of the concept of a positively charged lepton and antiparticle, tomography devices using positrons enable the hidden tumours in our body to be revealed. Let’s see what a positron is, what it does, where it is used in all details.
As the world of science develops day by day with the help of technology, new concepts continue to emerge. After the electron, proton and neutron, which are subatomic particles, we also met a particle called the positron. discovered nearly a hundred years ago. The first important example of the concept we call antiparticle for the positronpossible to say.
Of course, as an ordinary person, you can say that banana is a positron, you are right because scientific studies do not interest us much as long as they remain theoretical. The positron is not one of them because, thanks to a technology given positron emission tomography, hidden tumors that are not easily seen in our body are revealed. Let’s take a closer look at questions such as what is a positron, what is it for, where is it used.
First, let’s make a basic definition; What is a positron?
The positron, also called anti-electron, is considered to be the antimatter counterpart or antiparticle of the electron. It has the same mass as an electron. Annihilation occurs when an electron collides with a positron. In cases where the collision takes place at lower energies, two or more photons may be produced.
So how is the positron formed?
An interaction called positron emission radioactive decay, or the release of an energetic photon, It occurs when it interacts with a different atom and produces double production. A positron is also emitted as a result of positive beta decay in the neutron-deficient radioactive nucleus. Positron can be formed as a result of the decay of short-lived particles, or it can be produced by man.
Fine, but what does this positron do?
Namely; The positron, which is in a stable state in the vacuum, collides with the electron and causes annihilation. During this extinction, gamma radiation is released. In other words, even if the positron is not used alone, the reactions it creates after interacting with other subatomic particles are used. The most important examples of this are positron microscopy and positron emission tomography.
Much clearer images are obtained with the positron microscope:
According to an article published in the February 1998 issue of the Review of Scientific Instruments, Brandeis University, They developed the positron microscope, which took the scanning electron microscope one step further.This developed device was developed to produce a one-dimensional y-ray scan on 20 resolution targets.
A y-ray used in this way in the positron microscope is much more sensitive to large-scale defects. Because positron is captured much more easily in sample defects. Devices called repositron emission microscopy, developed in the following years, increase the chance of observing specific contrasts. Studies on this subject continue.
Occult tumors become visible thanks to positron emission tomography:
Positron emission tomography, also known as PET in short, is one of the nuclear imaging methods. It is considered to be the most effective imaging method in cases of tumors and metastases.because unlike the known tomography methods, it enables the visualization of hidden tumors that are not clearly visible in our body.
The details are a bit complicated, but to put it roughly; in the patient before the procedure There is a small amount of a radioactive substance called 18F. a sugary compound is given intravenously. When positron emission tomography works, it detects these substances that have gathered around the tumor cells. In other words, the tumor is exposed.
Do not be afraid of giving intravenous radioactive materials because they have a very short lifespan and It is excreted from the body in a very short time. Thanks to this advantage, the success of chemotherapy sessions can be observed in this way. Moreover, the spread of tumors that are thought to have disappeared but suspected to spread to the body can be revealed in this way.
The story of the discovery of the positron is quite interesting:
A physicist named Paul Dirac discovered in 1928 that electrons were simultaneously published an article claiming that it can be both negatively and positively charged. The situation in question through the zeeman effect; He explained it with the Dirac equation, which is a kind of mixture of quantum mechanics, special relativity and spin concepts.
In fact, this article was not talking about a new particle, but that an existing electron could have two opposite charges in solution. A theoretical physicist named Hermann Weyl He talked about the possible mathematical consequences of this situation. Paul Dirac was a little taken aback by this mathematical model. Unlike the known quantum mechanics equations, negative energy solution could not be ignored in this equation. Moreover, there was the possibility of a spontaneous jump between negative and positive charge.
In 1929, Paul Dirac wrote in an article. ‘An electron with negative energy moves in an external field as if it were carrying a positive charge.’placed the sentence. To eliminate the possibility of skipping we should have thought of the void as a sea of negative energy. Proton was an island in this sea. Finally, Dirac accepted the problem of the proton having a greater mass than the electron. Fortunately, there are different scientists researching the subject.
Positron: An electron going backwards in time
Robert Oppenheimer objected that the Dirac equation could be a solution to the negative electron. In 1931, Hermann Weyl, showed that the mass of negative electrons and positive electrons is the same. Revisiting these two ideas, Dirac published a paper on the prediction of an as yet unobserved particle he called the anti-electron.
Estimated by Richard Phillips Feynman and Ernst Stueckelberg, Dirac they said the positron should actually be interpreted as a version of the electron going backwards in time and they reinterpreted the Dirac equation. Yoichiro Nambu reinterpreted this particle on generation and destruction and explained the contrast with the following sentence;
“The eventual creation and destruction of pairs that may occur now and later is not creation or extinction, but merely a change of direction of moving particles from the past to the future or from the future to the future.”
Also known as anti-electron What is a positron, what is it for, where is it used We answered frequently asked questions such as: Since the positron and other subatomic particles are an ocean with a high probability of drowning when they dive into it, in this article we have only shared the basic information that will satisfy the curiosity of the people.