Don't be intimidated by the headline. The black hole, accidentally created by the staff of the National Accelerator Laboratory SLAC, turned out to be the size of only one atom, so that nothing threatens us. Yeah, and the title "black hole" only vaguely describes the phenomenon contemplated by researchers. We have repeatedly told you about the world's most powerful X-ray laser, bearing the title of Linac Coherent Light Source (Linear measure of coherent light - eng.). This design was developed so that researchers could see all the beauties of a microscopic level with their burkals. However, as a result of accident, the laser created a miniature molecular black hole.
In January 2012, LCLS was used to recreate a kind of tiny star in the laboratory. The laser created dense matter heated to a temperature of 2,000,000 degrees Celsius. Scientists for some time came close to understanding what actually happens inside the Sun. However, the researchers had no plans to create a black hole, even a molecular one. This event was the result of irreproachable coincidence during one of many experiments.
LCLS illuminates objects with unimaginably bright X-ray flashes lasting only a few femtoseconds. During the next experiment, scientists used mirrors in order to focus a laser beam into a spot with a total diameter of 100 nanometers, which is about 100 nanometers smaller than usual. The aim of the experiment was to find the reaction of heavy atoms to the impact of hard X-rays. That is why it was dignified to focus the laser beam as much as possible. The resulting power can be compared to all sunlight falling on the ground if you focus it on a spot the size of a human fingernail.
All this energy scientists have visited on xenon atoms, which include 54 electrons each, as well as on iodine atoms, which own 53 electrons. The researchers assumed that those electrons that are more intimate than the total to the center of the atoms will be removed, which, in fact, will allow for some time to create a semblance of "hollow atoms" until the electrons from the outer orbits begin to fill the intervals. In the case of xenon, this actually happened. But iodine behaved completely differently. Its atoms, depicting part of two molecules, after the loss of electrons turned into a kind of black hole, drawing in electrons from neighboring carbon and hydrogen atoms. The laser knocked out foreign electrons drawn into the atom until it completely destroyed the entire molecule.
It was assumed that the iodine atom would lose a total of 47 electrons, but taking into account the drawn in electrons from neighboring atoms, scientists counted 54 pieces. And this is about a smaller molecule. As for what touches a large molecule, researchers are still analyzing the results of the experiment. It is not so easy to do this, however, scientists plan to continue their research in the present current. The results of an unusual experiment were published in the journal Nature.
An international team of scientists found that when organic molecules are irradiated with intense X-rays, a microscopic analogue of a black hole appears. This discovery will help to more accurately figure out the structure of complex molecules and biological materials. talks about a new study published in the journal Nature.
Free electron X-ray lasers (XFELs) are lasers that generate X-rays suitable for studying the structure of biological molecules. A beam of electrons moving along a sinusoidal trajectory through an undulator (or wiggler), a device that is a series of magnets, is used as the working medium of the RFEL. In this case, the electrons emit photons, which form a narrow cone of X-ray radiation.
X-rays are electromagnetic waves with a fairly short wavelength, which makes them useful for studying very small objects (the shorter the wavelength, the finer details can be seen with it). However, there is a significant problem: short-wave radiation is high energy. As a result, instead of knowing the structure of a biological molecule, we burn it. Femtosecond lasers - ultrashort pulse lasers - help to get around this difficulty.
A femtosecond is one quadrillionth fraction of a second (10 -15 sec.) The X-ray pulses generated by this type of RFEL last approximately 5-50 femtoseconds. With such short, but super-powerful (up to 10 20 watts per square centimeter) pulses, the sample does not have time to collapse before scientists get an image of it. However, there are limitations here. These intense pulses are suitable for studying complex materials and biological systems, but not for basic molecular research, for which weaker X-rays are used.
The fact is that when atoms are irradiated with intense X-rays, they reach high degree ionization due to multiphoton absorption. In molecules consisting of different atoms, this happens with the heaviest atom (which has a higher ordinal number), provided that for it the probability of absorbing a photon is much higher than for neighboring nuclei. After that, the resulting charge is distributed throughout the molecule. Such ionization can lead to local damage to the sample and, as a consequence, distortion of the picture.
Scientists have learned to predict distortion using soft or not very intense X-ray pulses. For this, models were developed based on an isolated atom, ionized under the same conditions. However, it remained unknown whether it was possible to simulate the same processes in polyatomic molecules with harder and more intense radiation.
To answer this question, an international research team used the free electron laser LCLS (Linac Coherent Light Source) at the SLAC National Accelerator Laboratory in the United States. Isolated xenon atoms, molecules of gaseous iodomethane (CH 3 I) and iodobenzene (C 6 H 5 I) were exposed to X-rays at a photon energy of 8.3 keV and an intensity of 10 19 watts per square centimeter. The duration of each pulse was less than 30 femtoseconds. The yield and kinetic energy of the formed ions were measured.
It was found that the maximum levels of ionization of xenon atoms and iodine ions CH 3 I were comparable with each other (48+ and 47+, respectively). This was not observed in experiments with soft X-rays and photon energies of 5.5 keV, where the level of ionization of individual atoms was higher than that of atoms with a close serial number in the molecule. The largest charge obtained for the entire iodomethane molecule reached 54+ (this means that X-rays knocked out 54 electrons from it), which exceeded the maximum positive charge of xenon.
Physicists used a theoretical model to explain this result. The hydrogen and carbon contained in CH 3 I absorb photons insignificantly due to their small effective cross section. This quantity determines the probability of interaction of an atom with a particle, and it depends on the size of the atom.
The larger iodine atom has a larger effective cross section. Almost all the photons absorbed by the molecule fall on it, and this leads to its ionization - the loss of 47 electrons (carbon also ionizes, but only by four electrons). The Auger effect arises when an atom becomes unstable and is forced to fill the vacancies that have arisen with electrons located on other (outer) electron shells. As a result, energy is released, which can be transferred to other electrons, forcing them to leave the atom. Thus, the process takes on a cascading nature. As a result, a high positive charge is formed, localized in the iodine atom.
The mechanism proposed by the researchers, which they called CREXIM (charge-rearrangement-enhanced X-ray ionization of molecules), makes it possible to predict experimental data. This is important because “black holes” cause a positive charge to repulse the molecule to pieces, and this distorts the resulting image. Iodomethane in this work serves as a "model" molecule, by which one can judge the behavior of other, more complex molecules.
Don't be intimidated by the headline. The black hole, accidentally created by the staff of the national accelerator laboratory Slac, turned out to be only one atom in size, so nothing threatens us. And the name "Black Hole" only vaguely describes the phenomenon observed by researchers. We have repeatedly told you about the world's most powerful X-ray laser, called Linac Coherent Light Source (linear source of coherent light - eng
... This device was designed so that researchers could see with their own eyes all the beauties of the microscopic level. But as a result of chance, the laser created a miniature molecular black hole.
In January 2012, Lcls was used to recreate a kind of tiny star in the laboratory. The laser created dense matter, heated to a temperature of 2,000,000 degrees Celsius. Scientists have for some time come close to understanding what exactly happens inside the sun. But the researchers had no plans to create a black hole, even a molecular one. This event was the result of pure chance during one of the many experiments.
Lcls irradiates objects with incredibly bright X-ray flashes lasting only a few femtoseconds. In another experiment, scientists used mirrors to focus a laser beam into a spot with a diameter of only 100 nanometers, which is about 100 times smaller than usual. The aim of the experiment was to study the reaction of heavy atoms to the impact of hard X-ray radiation. That is why it was important to focus the laser beam as much as possible. The resulting power can be compared to all sunlight hitting the ground by focusing it into a spot the size of a human fingernail.
Scientists directed all this energy to xenon atoms, containing 54 electrons each, as well as to iodine atoms, which have 53 electrons. The researchers assumed that those electrons that are closest to the center of the atoms will be removed, which, in fact, will allow for a while to create a kind of "Hollow Atoms" until the electrons from the outer orbits begin to fill in the gaps. In the case of xenon, this is exactly what happened. But iodine behaved completely differently. Its atoms, which are part of two molecules, after the loss of electrons turned into a kind of black hole, drawing in electrons from neighboring carbon and hydrogen atoms. The laser knocked out foreign electrons drawn into the atom until it completely destroyed the entire molecule.
It was assumed that the iodine atom will lose only 47 electrons, but taking into account the drawn in electrons from neighboring atoms, scientists have counted 54 pieces. And we are talking about a smaller molecule. As for the large molecule, researchers are still analyzing the results of the experiment. It is not so easy to do this, but scientists plan to continue their research in this direction. The results of the unusual experiment were published in the journal Nature.
Don't be intimidated by the headline. The black hole, accidentally created by the staff of the SLAC National Accelerator Laboratory, turned out to be only one atom in size, so nothing threatens us. And the name "black hole" only vaguely describes the phenomenon observed by researchers. We have repeatedly told you about the world's most powerful X-ray laser, called the Linac Coherent Light Source (Linear source of coherent light). This device was designed so that researchers could see with their own eyes all the beauties of the microscopic level. But by chance, the laser created a miniature molecular black hole.
In January 2012, LCLS was used to recreate a kind of tiny star in the laboratory. The laser created dense matter heated to a temperature of 2,000,000 degrees Celsius. Scientists for some time came close to understanding what exactly happens inside the Sun. But the researchers had no plans to create a black hole, even a molecular one. This event was the result of pure coincidence during one of many experiments.
LCLS illuminates objects with incredibly bright X-ray flashes lasting just a few femtoseconds. In another experiment, scientists used mirrors to focus a laser beam into a spot with a diameter of only 100 nanometers, which is about 100 times smaller than usual. The aim of the experiment was to study the reaction of heavy atoms to the impact of hard X-ray radiation. That is why it was important to focus the laser beam as much as possible. The resulting power can be compared to all sunlight hitting the ground by focusing it into a spot the size of a human fingernail.
Scientists directed all this energy to xenon atoms containing 54 electrons each, as well as to iodine atoms, which have 53 electrons. The researchers assumed that those electrons that are closest to the center of the atoms will be removed, which, in fact, will allow for a while to create a kind of "hollow atoms" until the electrons from the outer orbits begin to fill in the gaps. In the case of xenon, this is exactly what happened. But iodine behaved completely differently. Its atoms, which are part of two molecules, after the loss of electrons turned into a kind of black hole, drawing in electrons from neighboring carbon and hydrogen atoms. The laser knocked out foreign electrons drawn into the atom until it completely destroyed the entire molecule.
It was assumed that the iodine atom will lose only 47 electrons, but taking into account the drawn in electrons from neighboring atoms, scientists have counted 54 pieces. And this is about a smaller molecule. As for the large molecule, researchers are still analyzing the results of the experiment. It is not so easy to do this, but scientists plan to continue their research in this direction. The results of the unusual experiment were published in the journal Nature.
Scientists accidentally create a molecular black hole
Don't be intimidated by the headline. The black hole, accidentally created by the staff of the SLAC National Accelerator Laboratory, turned out to be only one atom in size, so nothing threatens us. And the name "black hole" only vaguely describes the phenomenon observed by researchers. We have repeatedly told you about the world's most powerful X-ray laser, called the Linac Coherent Light Source (Linear source of coherent light). This device was designed so that researchers could see with their own eyes all the beauties of the microscopic level. But as a result of chance, the laser created a miniature molecular black hole.
In January 2012, LCLS was used to recreate a kind of tiny star in the laboratory. The laser created dense matter, heated to a temperature of 2,000,000 degrees Celsius. Scientists for some time came close to understanding what exactly happens inside the sun. But the researchers had no plans to create a black hole, even a molecular one. This event was the result of pure coincidence during one of many experiments.
LCLS illuminates objects with incredibly bright X-ray flashes lasting just a few femtoseconds. In another experiment, scientists used mirrors to focus a laser beam into a spot with a diameter of only 100 nanometers, which is about 100 times smaller than usual. The aim of the experiment was to study the reaction of heavy atoms to the impact of hard X-ray radiation. That is why it was important to focus the laser beam as much as possible. The resulting power can be compared to all sunlight hitting the ground by focusing it into a spot the size of a human fingernail.
Scientists directed all this energy to xenon atoms, containing 54 electrons each, as well as to iodine atoms, which have 53 electrons. The researchers assumed that those electrons that are closest to the center of the atoms will be removed, which, in fact, will allow for a while to create a kind of "hollow atoms" until the electrons from the outer orbits begin to fill in the gaps. In the case of xenon, this is exactly what happened. But iodine behaved completely differently. Its atoms, which are part of two molecules, after the loss of electrons turned into a kind of black hole, drawing in electrons from neighboring carbon and hydrogen atoms. The laser knocked out foreign electrons drawn into the atom until it completely destroyed the entire molecule.
It was assumed that the iodine atom will lose only 47 electrons, but taking into account the drawn in electrons from neighboring atoms, scientists have counted 54 pieces. And this is about a smaller molecule. As for the large molecule, researchers are still analyzing the results of the experiment. It is not so easy to do this, but scientists plan to continue their research in this direction. The results of the unusual experiment were published in the journal Nature.
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