What is gamma ray? What are alpha rays, beta rays and gamma rays?
Alpha ray
Alpha rays, also known as alpha particle beams, are helium nuclei moving at high speed. Alpha particles consist of two protons and two neutrons. Its static mass is 6.64 * 10-27kg and its charging capacity is 3.20* 10- 19. In physics, he is used to represent alpha particles or helium nuclei. Rutherford first discovered that natural radioactivity is several different rays. He named positively charged rays alpha rays; Electronically charged rays are called beta rays. In a series of later experiments, Rutherford and others confirmed that alpha particles were helium nuclei.
β ray
β-ray: the high-speed electron current is 0/- 1e, with strong penetration and weak ionization. Originally, there was no distinction between left and right in the physical world, but there was a distinction between left and right in beta rays. Beta particles, that is, beta particles, refer to high-energy electrons released when radioactive substances undergo beta decay, and their speed can reach 99% of the speed of light. In the process of beta decay, radioactive nuclei are transformed into another kind of nuclei by emitting electrons and neutrinos, and the electrons in the products are called beta particles. In the positive beta decay, a proton in the nucleus is transformed into a neutron and a positron is released at the same time. In negative beta decay, a neutron in the nucleus is converted into a proton, and at the same time an electron, namely a beta particle, is released.
Gamma ray
Gamma ray, also known as gamma particle stream, is an electromagnetic wave with a wavelength less than 0.0 1 angstrom. Gamma rays have strong penetrating power and can be used for flaw detection or automatic control of assembly line in industry. Gamma rays are lethal to cells and are used to treat tumors in medicine. Gamma ray was first discovered by French scientist P.V. Vilade, and it is the third nuclear ray discovered after α and β rays.
Harm of gamma rays
Gamma rays have strong penetrating power. When the human body is irradiated by gamma rays, gamma rays can enter the human body and ionize with cells in the body. Ions produced by ionization can corrode complex organic molecules, such as protein, nucleic acids and enzymes.
They are the main components of living cells and tissues. Once they are destroyed, the normal chemical processes in the human body will be disturbed, which will seriously lead to cell death.
Extended data:
First, the production principle
The new nuclei produced by radioactive nuclei after α decay and β decay are often at high energy level, so they should jump to low energy level and radiate γ photons. Both nuclear decay and nuclear reaction produce gamma rays. Which is an electromagnetic wave with a wavelength less than 0.2 angstrom. The wavelength of γ -ray is shorter than that of X-ray, so its penetrating power is stronger than that of X-ray.
Gamma rays are electromagnetic photons with frequencies higher than 1.5 trillion hertz. Gamma rays have no charge and rest mass, so their ionization ability is weaker than that of alpha particles and beta particles. Gamma rays have strong penetrating power and high energy. Gamma rays can be stopped by nuclei with high atomic number, such as lead or depleted uranium.
Second, the measurement method
Gamma photon is uncharged, so its energy cannot be measured by magnetic deflection method. Usually, the above-mentioned secondary effect caused by gamma photons is used for indirect calculation, for example, by measuring the energy of photoelectrons or positive and negative electron pairs. In addition, the energy of gamma photons can be directly measured by gamma spectrometer (using the interaction between gamma rays and matter).
Scintillation counter composed of fluorescent crystal, photomultiplier tube and electronic instrument is a common instrument for detecting γ -ray intensity.
Sogou Encyclopedia-Gamma Ray
What is gamma ray?
α -ray is helium nuclear current, β -ray is electron current γ-ray, and its wavelength is less than 0. 1 nm, which is a kind of radiation with higher energy than X-ray. Li Qibin put forward seven astronomical research fields in this century.
Three of them involve the exploration of extraterrestrial energy, one is dark energy related to dark matter, the other is quasar with huge radiant energy, and the other is a huge energy source from outside the river. Only a few percent of space matter has been seen by humans, and more than 90 percent of matter is dark, which humans have never seen. This is dark matter.
When it comes to dark matter, it is easy for human beings to think of "black holes". Black holes are dark matter.
The gravity of a black hole is so great that satellites launched from the earth can only rush out of the atmosphere at the first cosmic speed of 7.8 km/s, but launching at the speed of light on a black hole still cannot surpass its huge gravity. According to Hawking's black hole theory, black holes can be determined by observing things around them.
If things around you fall, they will emit X-rays and produce X-halo. According to the observation of X-rays, black holes can be identified. If a star has been observed to revolve around a hole, it can also be inferred that there is a black hole in the middle of its orbit.
The discussion of quasars belongs to the observation in the field of intense activity of celestial bodies. Li Qibin explained that the mystery of quasars is that they radiate more energy per second than the sum of 654.38+000 billion stars in the whole galaxy.
Astronomers speculate that there must be a unique way to provide energy. The discovery of gamma ray bursts is dramatic.
People first observed gamma rays to monitor nuclear tests. When the instrument was accidentally aimed at the air, gamma rays from space were found. As a result, people have discovered stars that emit gamma rays, some of which are explosive.
Observations by space probes show that the average frequency of gamma-ray bursts is once a day. Gamma ray bursts are as powerful as quasars.
Li Qibin is optimistic that if we can observe and analyze their energy sources, we may be able to solve the human energy crisis and energy development at the expense of destroying the environment. At the end of 2003, American Science magazine named the top ten scientific and technological achievements of that year, and the research on cosmic gamma rays was selected among them.
This study improves the understanding of cosmic gamma-ray bursts and confirms the connection between gamma-ray bursts and supernovae. 65 million years ago, an asteroid crashed into the earth, which led to the extinction of dinosaurs.
However, according to the British "New Scientist" magazine in 2003, there is far more than one killer from outer space. The latest scientific research shows that as early as 400 million years ago, the earth experienced another mass extinction, and the culprit was the "gamma rays" that broke out after the collapse of the stars in the Milky Way! In astronomy, gamma ray bursts are called "gamma ray bursts". What exactly is a gamma-ray burst? Where did it come from? Why does it generate so much energy? "Gamma-ray burst is a sudden increase of gamma rays in the universe."
Zhao Yongheng, a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, told reporters that gamma rays are electromagnetic waves with a wavelength less than 0. 1 nm, which is a kind of radiation higher than X-ray energy, and the energy is very high. But most gamma rays will be blocked by the earth's atmosphere, and observation must be carried out outside the earth.
During the Cold War, the United States launched a series of military satellites to monitor nuclear explosions around the world. These satellites are equipped with gamma-ray detectors to monitor a large number of high-energy rays produced by nuclear explosions. 1967, the reconnaissance satellite discovered the phenomenon that gamma rays from the vast space suddenly increased in a short time, which was called "gamma ray burst".
This discovery was not published until 1973 due to military secrecy and other factors. This is a phenomenon that puzzles astronomers: some gamma-ray sources suddenly appear for a few seconds and then disappear.
This explosion releases energy with very high power. The brightness of gamma-ray bursts is equivalent to the sum of the brightness of all gamma-ray sources in the whole day.
Subsequently, high-energy astronomical satellites are constantly monitoring gamma-ray bursts, and one or two gamma-ray bursts are observed almost every day. The energy released by gamma ray bursts can even be compared with the Big Bang.
According to researcher Zhao Yongheng, the duration of gamma-ray bursts is very short, usually tens of seconds long, and the short one is only a few tenths of a second. And its brightness change is complicated and irregular.
However, the energy released by gamma ray bursts is enormous. The gamma ray energy emitted in a few seconds is equivalent to the sum of the energy released by hundreds of suns in their lifetime (654.38+000 billion years)! The gamma-ray burst that occurred on 1997 14 February 14 is as far away from the earth as1200 million light years, and the energy released is several hundred times larger than that of a supernova explosion. The gamma ray energy released in 50 seconds is equivalent to the total radiation energy of the whole galaxy in 200 years. This gamma ray burst is as bright as the whole universe except it in a second or two.
Within a few hundred kilometers near it, the high temperature and high density of the last thousandth of a second of BIGBANG are reproduced. However, the gamma-ray burst that occurred on 1999123 October was more violent than this one, and its energy was ten times that of 1997, which is also the most powerful gamma-ray burst known to mankind so far.
The reason caused a big debate. There is no final conclusion about the cause of gamma-ray bursts in the world. Some people speculate that it is produced when two neutron stars or two black holes collide; Some people suspect that it is produced in the process of forming a black hole when a massive star dies, but this process is much stronger than a supernova explosion, so some people call it a "super supernova".
Researcher Zhao Yongheng said that in order to explore the causes of gamma-ray bursts, there was a big debate between the two astronomers. In 1970s and 1980s, it was generally believed that gamma ray bursts occurred in the Milky Way, and it was speculated that it was related to the physical process on the surface of neutron stars.
However, Polish-American astronomer Pachinsky is unique. In the mid-1980s, he proposed that gamma-ray bursts are celestial bodies as distant as quasars in the universe, but in fact gamma-ray bursts occur outside the Milky Way.
But at that time, people had been ruled by the theory of gamma-ray bursts in the Milky Way for many years, so they had different views on Paczensky.
What is gamma ray?
Gamma ray, also known as gamma particle flow, is transliterated as gamma ray in Chinese. Electromagnetic waves with a wavelength shorter than 0.2 angstrom [1]. It was first discovered by French scientist Vilade, and it is the third nuclear ray discovered after α and β rays. Both nuclear decay and nuclear reaction produce gamma rays. Gamma rays are more penetrating than X rays. When γ -rays pass through matter and interact with atoms, there will be three effects: photoelectric effect, Compton effect and positive-negative electron pair. When the gamma photons released by the nucleus collide with the electrons outside the nucleus, all the energy will be given to the electrons, and the electrons will be ionized into photoelectrons, which is the photoelectric effect. Because of the vacancy of the outer electron layer, the transition of the inner electron will occur and the X-ray discrimination spectrum will be emitted. High-energy gamma photons (>: 2 million electron volts) are very weak. When the energy of gamma photon is high, besides the photoelectric effect mentioned above, it may also collide with extranuclear electrons elastically, and the energy and moving direction of gamma photon will change, thus producing Compton effect. When the energy of γ photon is more than twice the rest mass of electron, it is transformed into a pair of positive and negative electrons due to the action of nucleus, and this effect is enhanced with the increase of γ photon energy. Gamma photon is uncharged, so its energy cannot be measured by magnetic deflection method. Usually, the above-mentioned secondary effect caused by gamma photons is used for indirect calculation, for example, by measuring the energy of photoelectrons or positive and negative electron pairs. In addition, the energy of gamma photons can be directly measured by gamma spectrometer (using the diffraction of gamma rays by crystals). Scintillation counter composed of fluorescent crystal, photomultiplier tube and electronic instrument is a common instrument for detecting γ -ray intensity.
The energy level structure of nuclear can be understood by studying γ -ray energy spectrum. Gamma rays have strong penetrating power and can be used for flaw detection or automatic control of assembly line in industry. Gamma rays are lethal to cells and are used to treat tumors in medicine.
Detecting gamma rays is helpful to the study of astronomy.
When humans observe space, they see "visible light". However, most of the electromagnetic spectrum is composed of different radiations, the wavelengths of which are longer or shorter than those of visible light, and most of them are invisible to the naked eye alone. Detecting gamma rays can provide space images invisible to the naked eye.
Gamma rays produced in space are produced by nuclear fusion in the core of a star. Because they cannot penetrate the earth's atmosphere and reach the lower atmosphere of the earth, they can only be detected in space. Gamma rays in space were first observed in 1967 by an artificial satellite named villars. In the early 1970s, gamma-ray images detected by different satellites provided information about hundreds of previously undiscovered stars and possible black holes. Satellites launched in 1990s (including Compton γ -ray Observatory) provide different astronomical information about supernovae, young clusters and quasars.
Gamma-ray is a kind of strong electromagnetic wave with shorter wavelength than X-ray, and the general wavelength of gamma-ray has strong penetration ability. When the human body is irradiated by gamma rays, gamma rays can enter the human body and ionize with cells in the body. Ions produced by ionization can corrode complex organic molecules, such as protein, nucleic acids and enzymes, which are the main components of living tissues. Once they are destroyed, the normal chemical processes in the human body will be disturbed, which will seriously lead to cell death.
What is gamma ray?
Scientists observed the scene after the gamma ray burst, and witnessed the destruction of a huge star and the birth of a rotating black hole. This observation is the most detailed record of gamma ray burst so far, and the observation results have been published in the journal Nature on March 20th. GRB is the most powerful explosion known in the universe at present. The energy released by gamma explosion is several hundred times that of supernova explosion, and the brightness reaches one billion times that of the sun at its highest. Scientists' observation of gamma explosions shows that gamma explosions occur very frequently, uniformly and randomly in the universe, so scientists believe that gamma explosions occur in celestial bodies quite far away from us. One of the main reasons why scientists are interested in gamma explosions is to know the origin of these powerful explosions. It is now believed that gamma-ray bursts may be caused by the collision of two black holes or neutron stars, or by the collapse of a massive star into a black hole when it dies. Although gamma-ray bursts are very frequent, it is difficult to observe them immediately because their position and direction are unpredictable and their duration is short. Generally speaking, large-scale gamma-ray bursts only last for a few seconds or even milliseconds. This successful observation benefited from ——Hete, a high-energy transient explorer of NASA. Ground-based robotic telescopes and fast-moving researchers are all over the world. The gamma explosion named GRB02 1004 occurred at 8: 06 am Eastern Standard Time on June 4th, 2002. HETE immediately observed the event and informed observers around the world of the location and direction of the event after the gamma explosion lasted for a few seconds. A few minutes later, observers around the world observed the afterglow of the gamma explosion one after another. During the observation, scientists found that the afterglow of the gamma-ray explosion lasted for more than half an hour, which gave scientists a new understanding of its power. Dr George Rick of Massachusetts Institute of Technology said: "The power of gamma ray explosion is certainly many times greater than we originally thought. "Gamma rays may be just the tip of the iceberg in the explosion energy of gamma rays." Scientists believe that this gamma-ray explosion was observed as a black hole from the core of a star, whose mass is 15 times that of the sun.
What is a gamma-ray burst?
Gamma ray burst (GRB), also known as GRB, is a phenomenon that the intensity of gamma rays from a certain direction in the sky suddenly increases in a short time, and then rapidly decreases. The duration is 0. 1- 1000 seconds, and the radiation is mainly concentrated in the energy band of 0.1-1000 mev.
The gamma ray burst was found in 1967. For decades, people still don't know its essence, but it can basically be determined that it happened in a star-level celestial body on the cosmic scale. Gamma-ray bursts are one of the most active research fields in astronomy at present, and were rated as one of the top ten scientific and technological progress of the year by American Science magazine in 1997 and 1999 twice.
The basic introduction of gamma-ray bursts, referred to as "gamma bursts", is a phenomenon in which gamma rays suddenly increase in the universe. Gamma-ray is an electromagnetic wave with a wavelength less than 0. 1 nm, which is a kind of radiation higher than X-ray energy. The energy of gamma-ray bursts is very high, and the released energy can even be compared with that of BIGBANG, but its duration is very short, usually tens of seconds long, and the short one is only a few tenths of a second, and the brightness change is also very complicated and irregular.
Gamma ray bursts can be divided into two different types, and astronomers have long suspected that they are caused by two different reasons. The more common long gamma bursts (lasting 2 seconds to several minutes) have almost been explained clearly.
In the current picture, they are produced when a Wolf-Rayet stars with high temperature and supermassive collapses to form a black hole. Although short gamma-ray bursts are fleeting, Swift can now capture 10 short gamma-ray bursts every year, which provides a very valuable data source for our research.
Our current research shows that short gamma-ray bursts may come from the merger of two stars in a binary system and the simultaneous generation of black holes. The energy mechanism of gamma-ray bursts is still far from being solved, which is also the core problem of gamma-ray bursts research.
With the progress of technology, human beings will have a deeper understanding of the universe, and many problems that seem to be mysteries now may be solved in the future. Exploring the mysteries of the universe is not only the need for human beings to pursue scientific progress, but also the solution of these mysteries will ultimately benefit human beings themselves. The reason is what astronomers often say: it may be that this gamma-ray burst is too far away to be observed in the visible wavelength range.
The latest research reveals the mystery. Interstellar dust absorbs almost all visible light, but higher-energy gamma rays and X-rays can penetrate interstellar dust and be captured by telescopes on earth. Gamma-ray bursts It is generally believed that gamma-ray bursts cannot be caused by the death of massive stars.
Astronomers believe that most of these gamma bursts occur when supermassive stars run out of nuclear fuel. When the core of a star collapses into a black hole, the jet of matter rushes out at a speed close to the speed of light.
The jet flows out of the collapsed star and continues to travel into space, and interacts with the gas previously illuminated by the star, resulting in a bright afterglow that decays with time. Most gamma rays will appear bright in the visible range.
However, some gamma ray bursts are dark and cannot be detected by optical telescopes. A recent study shows that dark gamma-ray bursts are actually not unobservable because of the long distance, but because most of the visible light is absorbed by interstellar dust, which may be the birthplace of stars.
It triggered a mass extinction 400 million years ago. New research shows that gamma rays released by lightning may be the main reason for the formation of lightning. The gamma rays of the original lightning island may be the main reason for the formation of lightning.
This conjecture. Four years ago, the Florida Institute of Technology. Joseph dwyer, an astrophysicist at Compton Gamma Ray Observatory in the last century, suggested that lightning was discovered from the ground in the early 1990s.
Gamma rays. At that time, dwyer found that gamma rays were related to lightning from some academic reports with the wavelength of gamma rays less than 0. 1 nm. In order to prove magnetic waves, radiation energy is higher than X-rays.
Gamma rays showed this relationship, and he established a model to describe the formation of electric field in the earth's atmosphere. Gamma ray bursts release energy equivalent to the Big Bang.
The results of gamma-ray emission show that these gamma-ray emission bursts in the electric field are caused by the collision of high-speed electrons emitted by two neutron stars with other particles in the atmosphere, or the death collision of massive stars, which can produce powerful Lei Yin. At the same time, they are released in the process of black hole production. So far, there is no charge. Thunderstorm weather, updraft and bottom are conclusive.
However, scientists admit that downward flow promoted the interaction of water molecules. The intensity of electric field is that when there is huge cosmic energy, the proportion increases, and the finally released electrons will produce gamma rays close to the speed of light, such as thunderstorms. Although dwyer guessed that mysterious lightning might be formed by gamma rays released by thunderstorms.
Naturally, this is just a guess. Finally, there is no conclusion. It is a joint research conducted by tokyo institute of technology and Japanese Institute of Physics and Chemistry this year that lightning closest to gamma rays can be truly simulated and simulated.
The research team sent a gamma ray research team to observe the gamma rays formed in lightning at low altitude in the Sea of Japan. The physical discovery of gamma-ray bursts was inadvertently discovered by Klebesadel et al. during the nuclear explosion monitoring of American Vela satellite in 1967.
The birth of a star is associated with the death of an old star. Supermassive stars rapidly age and explode, and the interstellar dust emitted from them quickly fills the nebula, and new substances produced by the supermassive explosion also erupt into the nebula, and the density of the nebula becomes very large, giving birth to new stars.
In a galaxy full of interstellar dust, a large number of star birth and death cycles are taking place. Since stars are formed in interstellar dust regions, it can be speculated that dust clusters around dark gamma-ray bursts may be the place where stars are born.
During the Cold War, the United States launched a series of military satellites to monitor the global nuclear.
What is gamma ray?
(Reference reading) Gamma ray, also known as gamma particle flow, is an electromagnetic wave with a wavelength less than 0.2 angstrom, which is released when the nuclear energy level transitions. Gamma rays have strong penetrating power and can be used for industrial flaw detection or automatic control of assembly line. Gamma rays are lethal to cells. It is used to treat tumors in medical treatment. 20 1 1 year, university of strathclyde, England researched and invented the brightest gamma ray on the earth, which is 1 trillion times brighter than the sun. This will usher in a new era of medical research. Gamma ray waves are electromagnetic waves shorter than 0.2 angstrom [1]. Radioactive nuclei undergo alpha decay, and new nuclei produced after beta decay are often at high energy levels. Emit gamma photons. It was first discovered by French scientist Vilade, and it is the third nuclear ray discovered after α and β rays. Both nuclear decay and nuclear reaction can produce gamma ray-internal structure model diagram and y ray-internal structure model diagram. The wavelength of gamma rays is shorter than that of x rays. Therefore, the penetration of gamma rays is stronger than that of x rays. They can penetrate lead plates several centimeters thick. When γ -rays pass through matter and interact with atoms, there will be three effects: photoelectric effect, Compton effect and positive-negative electron pair. When the gamma photon released by the nucleus collides with the electrons outside the nucleus, it will give all the energy to the electrons and ionize them into photoelectrons, which is called photoelectric effect. Because of the vacancy of the outer electron layer, the inner electrons will jump and emit X-ray identification spectrum. High-energy gamma rays (2 mev) are very weak. When the energy of gamma photon is high, in addition to the photoelectric effect mentioned above, it may also collide with electrons outside the nucleus, and the energy and moving direction of gamma photon will change, resulting in Compton effect. When the energy of γ photon is more than twice the rest mass of electron, it is transformed into a pair of positive and negative electrons due to the action of nucleus, and this effect is enhanced with the increase of γ photon energy. Because γ -photon is uncharged, its energy cannot be measured by magnetic deflection method. Usually, the secondary effect caused by gamma photons is calculated indirectly, for example, by measuring the energy of photoelectrons or electron-positron pairs. In addition, the energy of γ photons can be directly measured by γ spectrometer (using the diffraction of γ rays by crystals). Scintillation counter composed of fluorescent crystal, photomultiplier tube and electronic instrument is a common instrument for detecting γ -ray intensity. By studying the spectrum of gamma rays, we can understand the energy level structure of the nucleus. Gamma rays have strong penetrating power. It can be used for industrial flaw detection or automatic control of assembly line. Gamma rays are lethal to cells and are used to treat tumors in medical treatment. Gamma rays are electromagnetic photons with frequencies higher than 1.5 trillion hertz. [1]γ rays have no charge and rest mass, so their ionization ability is weaker than that of α particles and β particles. Gamma rays have strong penetrating ability and high energy. Gamma rays can be stopped by nuclei with high atomic number, such as lead or nuclei lacking energy.