SPring, a large synchrotron radiation source in Japan
First, the third generation synchrotron radiation light source with the highest energy in the world
SPring-8, a large-scale synchrotron radiation facility in Japan, is located in Harima Science Garden City, Hyogo) in Hyogo Prefecture, the center of the Japanese archipelago. It is the third generation synchrotron radiation source with the highest energy in the world. Its English name is Spring-8, which means "8GeV Super Photon Ring", that is, the output power is 8 GeV.
In 1991, under the leadership of MEXT (Ministry of Education, Culture, Sports, Science and Technology), Jaeri (Japan Atomic Energy Research Institute) and Riken (the Institute of Physical and Chemical Research) of Japan began to jointly build SPring-8. The construction cost of the first phase is about 110 billion yen, and the land is donated by Hyogo Prefecture for free. With the joint support of the county government, the county university, various research institutes and commercial enterprises, the project was completed in 1997, and the facilities were opened, which were managed by JASRI (Japan Synchrotron Radiation Research Institute), including the operation, maintenance, transformation, user service and scientific research and development of light sources. JASRI is the only statutory management organization of SPring-8, which is private and non-profit, and employs more than 1,000 employees, 80% of whom are researchers and technicians. From October 1997 to 2010, SPring-8 has built 55 beam line stations.It has served more than 100,000 people in science, industry and business circles in Japan and the world.
Spring-8 in Japan, advanced photon source APS (Argone) in Argonne National Laboratory of the United States and European synchrotron radiation facility ESRF (Grenoble) in Grenoble, France are the three largest high-energy synchrotron radiation facilities in the world.
Geographical map of SPring-8 (image from Google)
SPring-8 is used in many scientific and medical fields, such as:
* Material science: studying the atomic and electronic structures of advanced materials, material properties under extreme conditions, etc.
* Biomedicine: analyzing protein structure, studying life mechanism, drug design and improvement, using phase contrast imaging method to perform high-resolution imaging of biological samples, etc.
Chemistry: kinetics under catalysis, atomic and molecular spectra, ultra-trace elements and their chemical properties;
Environmental science: catalysts for analyzing the environment, and trace elements of environmental pollution in biological samples;
:: Earth and Cosmic Science: Analysis of the structure and characteristics of deep crustal materials, and the structure of meteorites and cosmic layers;
* Industry and nuclear physics: using photon energy to study quark nuclear physics, etc.
Bird’s eye view of SPring-8
SPring-8 storage ring built around the mountain
Links: Some specific data of SPring-8.
* area: covering an area of 141 hectares, it is 36 times larger than Koshien Ballpark, 30 times larger than Tokyo Dome Stadium and 2.8 times larger than Tokyo Disneyland Theme Park. The large storage ring has a diameter of 457 meters, which is longer than the length of four football fields, and its circumference is about 1436 meters.
* Operating expenses are affected by the economic crisis, and are reduced almost year by year;
* Usage fee: 60,000 yen/hour. However, if scientists disclose their research results after this experiment, the use of light sources is free.
* Energy consumption: The Kansai Electric Power Co., Ltd. provides dedicated high-voltage power. In 2009, the annual electricity consumption was 178 million kilowatts, equivalent to the average annual electricity consumption of 49,000 households, costing 190 million yen; Natural gas is provided by the Technopolis Branch of Osaka Gas Co., Ltd. In 2009, it used 1.31 million cubic meters, equivalent to the gas used by 3,300 ordinary households, costing 80 million yen. Water is the responsibility of Three Cities-Towns’ Water and Sewage Office. In 2009, it used 280,000 tons of water, which is the same as the water used by 650 families for one year, costing 100 million yen.
Second, historical review
October 1988: A cooperative group of Japan Institute of Atomic Force (JAERI) and Institute of Physical Chemistry (RIKEN) was established to design and develop large-scale synchrotron radiation facilities.
June, 1989: The site was located in Sowing Science Garden City in Hyogo Prefecture.
December 1990: Japan Synchrotron Radiation Research Institute (JASRI) was established.
November 1991: SPring-8 project started.
May 1993: SPring-8 User Association was established.
October 1994: The "Law on the Promotion and Generalization of Synchrotron Radiation Facilities" was implemented, and JASRI was designated as "the institution to promote the research and use of Synchrotron Radiation".
March 1997: Synchrotron radiation successfully emerged for the first time.
October 1997: The project was completed. Light source on.
March 1998: The first SPring-8 user seminar was held.
May 1998: The current with a beam of 100mA was successfully stored in the storage ring.
June 2000: The first contracted beam line station began to operate.
August 2000: 25-meter-long undulator was installed.
October 1st, 2005: JAERI, Japan Atomic Energy Research Institute, was reorganized into JAEA(Japan Atomic Energy Agency), and left SPring-8. The light source is jointly managed by JASRI and RIKEN.
July, 2006: "Law on the Promotion and Generalization of Synchrotron Radiation Facilities" was amended as "Promoting the Publicity of Major Advanced Scientific Research Facilities".
March 2007: JASRI was elected as the only registered institution to promote the use of facilities.
October 2007: A grand ceremony and discussion were held to celebrate the 10th anniversary of the successful operation of the light source.
June 2009: SPring-8 received the 100,000 th user since its opening.
Third, structural exploration
The accelerator of SPring-8 mainly consists of four parts:
* injector, Linac, 1GeV；;
* Booster, 8 GeV;
* large Storage Ring, storage ring, 8GeV, used for high brightness X-ray;
* Small storage ring, NewSUBARU, 1.5GeV, used for medium short pulse soft X-ray.
1. Injector (Linac)
The linear accelerator section is equipped with 26 3-meter-long accelerating units to accelerate the electron beam energy to 1GeV. The red part in the picture below is a quadrupole magnet used to focus the electron beam.
Linear accelerator unit 1
The electron beam is generated by a thermionic gun impregnated with barium and tungsten. The ion gun is located on the high-voltage board with a voltage of about 180KV. The pulse duration is 1ns or 40ns. The selected beam is focused on a buncher and accelerated to 1GeV energy with 25 accelerating cavities. Electron beam energy dispersion is reduced by energy compressor system (ECS). Then, the linear accelerator as the injector transports the electron beam to the intensifier or the NewSUBARU small storage ring.
Some parameters of linear accelerator:
2. Booster Synchrotron
Annular, with a circumference of 396 meters. The 1GeV electron beam output from the linear accelerator will be accelerated to 8GeV in the intensifier. The blue image below shows the deflection magnet, which is used to generate synchronous radiation light; The yellow part is a six-stage magnet for stabilizing the electron beam.
Intensifier tunnel intensifier branch point (left) electron beam transport line SSBT (right)
In FODO, the magnetic focusing structure of the intensifier, bending magnets and quadrupole magnets are alternately arranged, and the repetition frequency of injection, acceleration and output is set to 1Hz, and the harmonic number is 672. If a single beam is injected into the storage ring, an RF elimination system is installed to eliminate other electron beams adjacent to the main beam. The special timing system injects different beams according to the types of light required by each outlet station of the storage ring.
Some parameters of the enhancer:
3. The large Storage Ring (storage ring)
The electron beam is injected into the storage ring from the transport line SSBT (left).
Huge ring with a circumference of 1436 meters. Its conventional unit consists of 2 deflection magnets, 10 four-stage magnets and 7 six-stage magnets, and its length is about 30 meters. The linear joints are located between conventional units, and are used to install plug-ins, RF accelerating cavities, beam injection systems, beam diagnosis systems, etc., with a total of 44 linear joints.
Some parameters of large storage ring:
The large storage ring can store 8GeV electron beams for a long time, more than 100 hours. The energy consumed by synchrotron radiation is replenished by accelerating equipment installed in four radio stations around the storage ring. The constant current (top-up) injection mode effectively ensures the constant beam current intensity in the storage ring.
Link: The 86th academic seminar of the Oriental Science and Technology Forum was held on December 7-8, 2006, with the topic of "beam orbit stability of the third generation synchrotron radiation light source".
Dr Kouichi Soutome from Japan synchrotron radiation research institute (JASRI) gave a special report on "constant current injection and beam orbit stability of SPring-8". He first emphasized the necessity of providing users with a stable X-ray beam for precision experiments. In order to stabilize the beam position, it is necessary to restrain the beam trajectory change. He pointed out that the top-up injection mode with constant beam intensity in the storage ring can effectively ensure the stability of the synchrotron radiation light intensity. For this reason, SPring-8 has made great efforts to study the sources of various factors that cause orbit change, such as the change of magnet power supply and the vibration of vacuum chamber caused by cooling water.
SPring-8 also improves the beam trajectory correction system and the corresponding measurement system. For top-up implantation, SPing-8 adopts many measures, such as reducing the vibration of stored electron beam caused by implantation, reducing the loss of implanted electron beam, and maintaining long-term high-purity single beam implantation. Finally, he reported the stability of SPring-8 in beam orbit and the performance of top-up injection operation mode. The total current stability in SPring-8 storage ring is controlled within 0.1%, and the current intensity inconsistency of each beam is also controlled within 10%.
4. NewSUBARU
NewSUBARU storage ring
NewSUBARU, a small storage ring with 1.5GeV, is mainly used to study the application of soft X-ray in industrial field. Built in 1998, Lasti (Laboratory of Advanced Science and Technology for Industry) of Hyogo University is responsible for its operation.
The circumference of the small storage ring is about 119 meters, and it consists of two 14-meter and four 2.6-meter straight-line sections. In the long straight section, an 11-meter-long undulator and an optical klystron free electron laser device are installed. The electron beam of 1GeV in the linear accelerator can be directly injected into the storage ring.
11-meter-long undulator
Some parameters of small storage ring:
Four, beam line and experimental station
SPring-8 has 22 beam lines led by deflection magnets, and up to 24 can be built. There are 26 beam lines led out by the insert, up to 34 can be built, and the length of the straight line section is 4.5 meters; There is one beam line led by the long insert, and at most four beams can be built, and the length of the long straight line section is 25m. These beam lines are generally designed within 80 meters, but 9 can extend to 300 meters and 3 can extend to 1 kilometer.
1. Layout and classification
The front-end assembly of the beam line is designed to withstand radiation power, reduce the thermal load of the first optical element in contact, and protect the vacuum of the storage ring in case of beam line failure.
Beam line front end
Beam line
* common beam line
* Japan Atomic Energy Development and Research Institute (JAEA) beam line
* RIKEN beam line
* Other unit beam lines
* accelerator beam diagnosis
* Taiwan Province’s exclusive beam line
Taiwan Province National Synchrotron Radiation Research Center has built two hard X-ray beams dedicated to Taiwan Province on SPring-8: for the study of biological structures and materials and inelastic X-ray scattering. Taiwan Province has 75% to 80% of the usage time.
chronicle of events
December 18th, 1998: Signed the cooperation memorandum and contract of SPring-8 Taiwan Province exclusive beam line.
October, 2000: Research on Biological Structure and Materials: The beam line came out and started trial operation. Derived from the deflection magnet of the storage ring, it can be used for researchers to engage in experiments such as X-ray absorption spectrum, high-resolution X-ray scattering, protein crystallography and micro-area diffraction, conduct forward-looking scientific experiments in life science, physics and chemistry, and open up new research fields of various cutting-edge materials.
December 15th, 2000: Opening ceremony of beam line was held.
At the beginning of 2001: Inelastic X-ray scattered beam line, which is led out by the storage ring frequency-concentrating magnet, is used for researchers to conduct cutting-edge research on high-coherence electronic systems (high-temperature superconductivity and giant magnetoresistance prospective materials).
December 2, 2010: The 10th Anniversary Celebration of Taiwan Province’s Exclusive Beam Line was held. Up to now, 483 projects and 1657 experiments have been carried out, and 233 SCI papers have been published in internationally renowned scientific journals, which has a broad user base and fruitful results.
2. Introduction of some experimental stations
* BL02B2 (powder diffraction)
A large Debye-Scherrer camera with a radius of 286.5mm was installed in the shed. Its imaging plate is the detector, which is used to collect all powder patterns synchronously. The camera can be used in a wide temperature range (15 k—1000 k), and it can realize the rapid collection of high calculation statistics and high angular resolution powder diffraction data.
* BL04B1 (high pressure and high temperature)
SPEED-Mk. II, a high-pressure equipment, is a double-layer 1500-ton tamping multi-anvil press. It uses 14*14*14mm sintered diamond anvil to produce high pressure and high temperature conditions, reaching 50 GPa and 2000oC. It can complete the experiments of energy dispersive X-ray diffraction and high-speed CCD imaging.
* BL08W (high energy inelastic scattering)
Compton scattering magnetic spectrometer is mainly composed of 3 T superconducting magnet and 10 germanium solid state detectors (SSDs). Superconducting magnet can switch the magnetic field from -3 T to 3 T within 5 seconds. Germanium SSDs are symmetrically arranged around the grazing X-ray beam, achieving a scattering angle of nearly 180 degrees. The sample temperature is controlled by a cryocooler, which is between 10 K and room temperature.
* BL13XU (surface and interface structure)
Ultra-high vacuum chamber (used for the surface of crystal materials such as metals and semiconductors) is installed on a huge X-ray diffractometer (3m in diameter and 2.3m in height). The cavity is equipped with standard surface analysis tools, such as LEED and RHEED.
* BL19B2 (Engineering Science Research I)
The mid-band hard X-ray beam station led by the bending magnet is open to industrial users. The main technologies are X-ray absorption, diffraction, scattering and imaging. It has three experimental shacks:
Shack 1: XAFS. The distance from the light source is 51m, and the length * width * height are 4m*3m*3.3m respectively. X-ray absorption and fine structure measurement were carried out in transmission and fluorescence modes, and high-energy X-ray fluorescence (XRF) analysis was carried out.
Shed II: X-ray diffraction. It is 77m away from the light source and 5m*4m*3.3m in length * width * height. The multi-axis diffractometer was installed to measure the residual stress and analyze the film structure, and the Debye-Scherrer camera was used for powder diffraction research.
Shed III: The distance from the light source is 111m, and the size is 8m * 4m * 3.3m.. X-ray imaging technology is used to observe industrial materials.
* BL27XU (soft X-ray photochemistry)
The C2a experimental station of the beam line is equipped with a hemispherical high-resolution electron energy analyzer (Gamma Data-Scientita, SES-2002) for studying free atoms and molecules. The sample gas is injected by MB Scientific AB. The decrease of resolution caused by Doppler effect of the gas sample will reduce the kinetic energy of the molecular beam source.
* BL35XU (high resolution inelastic scattering)
IXS spectrometer is a special scientific instrument, which needs very precise "arm" movement, and the "arm" is long and heavy, 10 meters, 6 tons (below), and it has to rotate at a large angle: 55 degrees. Its length is to ensure good energy resolution (?1 meV), and its weight is in the vacuum flight orbit to prevent the scattering and absorption of X-rays. In addition, vacuum insulation is used to control the temperature (MK) of optical instruments very accurately.
* BL37XU (trace element analysis)
This beam line is specially designed for all kinds of "X-ray fluorescence analysis".
Shed 1: equipped with high spatial resolution X-ray microprobe, multifunctional X-ray diffractometer, X-ray fluorescence analyzer and high-energy X-ray fluorescence spectrometer.
Shed 2: equipped with grazing incidence spectrum reflectometer and low vacuum scanning electron microscope SEM.
* BL15XU（WEBRAM）
Intelligent dual-angle photoelectron analyzer (DAPHNIA) is used to measure photoelectrons and Auger electrons, and the "takeoff angle" can be set separately. Provide large photoelectron kinetic energy up to 4800 eV. The instrument has shown good performance in using high energy excitation beam. For example, electron excitation in a deeper core layer or the application of high kinetic energy photoelectrons.
* BL24XU (Hyogo Prefecture)
The following picture shows the instrument used for X-ray microanalysis in the beam line shed C. The instrument uses a phase zone plate to form a strong X-ray microbeam, which can be used in many fields, such as two-dimensional drawing of trace elements in samples, micro-diffraction of polymers and stress analysis in laser diodes.
* BL23SU (actinide science I)
The following picture shows a high-resolution photoelectron spectrometer and a soft X-ray magnetic circular dichroism (MCD) for measurement. The energy resolution of photoelectron spectrometer is less than 2 meV. The maximum magnetic field measured by MCD’s superconducting magnet is 10 t. These two instruments are used to study the electronic structure of actinide materials, such as uranium compounds.
* BL45XU (structural biology I)
There are two experimental stations for structural biology research. Protein Crystallography Experimental Station uses MAD method in the field of X-ray crystallization, that is, multi-wavelength abnormal diffraction to utilize synchrotron radiation. The trichromator for protein crystal installed on the goniometer can generate three different wavelengths of X-rays.
angular instrument
V. Major scientific research achievements
1. Uncover the secret of the mysterious structure and movement mode of water molecules.
Water is a familiar substance, and the structure of water molecule H2O is well known. But perhaps people haven’t thought deeply: where does ice store huge cooling energy? Why is the density of water the highest at 4oC? But above or below 4oC, the water density decreases? Why is the density of solid ice less than liquid water?
Japanese scientists analyzed the structure of water and ice in SPring-8, and some new discoveries solved the long-debated problem about the nature of water. They successfully conducted Compton scattering experiment by using high-energy inelastic scattering beam line BL08W, directly observed the structure and function of ice at high resolution, and verified the accuracy of molecular dynamics simulation. This basic research result can help to develop thermal storage materials and analyze the thermal storage of new materials in the future. The paper was published in the top American science journals.
In fact, as early as 2008, scientists from RIKEN Institute of Physics and Chemistry in Japan proposed two water states with different hydrogen bonding modes by using BL17SU beam line and soft X-ray spectrum of SPring-8, as well as small angle scattering and Raman scattering.
2. Develop general-purpose plastic materials as strong as iron.
Plastic products such as plastic bags and plastic buckets have become widely used and indispensable items in our daily life because they are light, waterproof and cheap. But at the same time, it also has some disadvantages: low tensile strength, easy deformation and not high temperature resistance. They are synthesized from polymers such as polyethylene and polypropylene, and their structures at the molecular level are composed of long chains of carbon atoms. This "string" structure of polymer makes plastic products as soft as biomaterials. However, scientists have found that the tensile strength of materials will increase with the increase of polymer chain length; When carbon chains have tensile strength similar to covalent bonds of carbon atoms in diamonds, general plastics will harden, but they will not have diamond-like strength.
Distinguished professor Hikosaka of The Graduate School of Integrated Arts and Sciences (Hiroshima University) focuses on the study of polymer long chains and their structural and characteristic changes. He examined the blending phase structure of polyethylene long chain and its influence on properties by X-ray diffraction and other methods. The growth mechanism, sliding and diffusion effect mechanism of ideal polymer crystals are formulated. In 1987, the "sliding diffusion theory of polymer crystallization" was put forward.
The research team led by Professor Iwasaka and his doctoral student Kiyoka Okada, who used BL40B2 beam line in 2003-2007, observed the process of nuclear nucleation. ) From 2007 to 2010, using the X-ray scattering device of SPring-8, a new polypropylene-based plastic with strong tensile force and super heat resistance was successfully developed for the first time: NOCs(nano-oriented crystals).
The reason why ordinary plastics have poor tensile strength is because of low crystallinity. High-quality plastics are those with crystallinity of about 50%. In other words, the higher the crystallinity, the stronger the intermolecular interaction, and the stronger the tensile strength and heat resistance. When polymer molecules are regularly arranged, crystals form. Therefore, in order to improve the crystallinity, it is necessary to arrange the polymer molecules regularly as much as possible.
Professor Masamichi Hikosaka, Dr. Kiyoka Okada, holds a new type of polypropylene.
The research team led by Professor Iwasaka found a method to make polymers regularly arranged when plastics are in molten state, and proved that the crystallinity of the method is 92%. Because the structure of NOCsS looks like a real armor, it is composed of small pieces of iron plates, so the model is called "real armor" model. The tensile strength of the new polypropylene is about seven times higher than that of the ordinary plastic material, the heat-resistant temperature reaches 170°C or higher than 176°C, the light transmittance is 99%, and it is recyclable and cheap, because only one process is needed in the traditional polypropylene production process.
This wonderful new plastic material is most likely to be used in the transformation of steel body in traditional automobile industry. Although the thickness of the body will be doubled, its weight is only a quarter of that of steel.
3. Analyze the change of dynamic structure of calcium pump.
A variety of ions participate in the biological activity of organisms. Calcium 2+ ion promotes muscle movement and is one of the most important ions in organisms. It is stored in the endoplasmic reticulum of myofibrils. When calcium ions are released into muscle cells, muscles contract. At the same time, calcium ions need to return to the endoplasmic reticulum to relax the muscles. A membrane protein called calcium pump is responsible for pumping back calcium 2+ ions.
Pumping back calcium ions involves two processes: obtaining and releasing, and the structure of calcium pump changes accordingly. Chikashi Toyoshima (Institute of Molecular and Cellular Biosciences of the University of Tokyo) first discovered this structural change and analyzed the calcium pump structure in nine states.
His research results were published in the British journal Nature in 2000, 2002 and 2004. In view of this series of outstanding achievements, Professor Toyoda was awarded the Asahi Prize in 2009.
A certain state in the reaction cycle of calcium pump
Left: Schematic diagram of structural changes of calcium pump. The figure shows a link of structural change in the calcium pump reaction cycle: ATP is bound and Ca2+ ions are trapped in membrane proteins. The structural changes in the middle are presented in gray.
Right: cover of Nature magazine in 2000.
4. Discovery of new magnetic materials on meteorites
Every year, thousands of tons of meteorites fall to the earth. Although their surfaces are burnt black, their internal metal and mineral components remain unchanged, so they are called "fossils" in space. It provides powerful evidence for human beings to understand the mysteries of the solar system.
Masato Kotsugi, JASRI) of Japan Synchrotron Radiation Research Institute used the Photoelectron Emission Microscope (PEEM) on BL25SU beam line of SPring-8 to analyze the structure of iron meteorites. Iron meteorite is composed of α phase rich in iron and γ phase rich in nickel. Dr. Xiao Shan confirmed that there is a nano-scale mineral layer at the interface between iron and nickel, which is called Tetrataenite. However, it does not exist on the earth and will become an excellent new magnetic material. Dr. Xiao Shan further analyzed the characteristics of Tetrataenite, which is composed of 50% iron and 50% nickel, and the iron and nickel atoms are alternately arranged, which is a regular periodic crystal structure. It produces a kind of hard magnetism, that is, the magnetization direction will not change easily. Famous hard magnetic materials include permanent magnets and materials used in engines of hybrid vehicles.
Another important discovery of Dr. Xiao Shan: Tetrataenite will be a potential substitute in hard disk manufacturing. Platinum is an indispensable material for the next generation hard disk, but it is a rare metal, and its price is rising. At present, the demand for platinum has exceeded its production capacity. About 2 tons of platinum is used in global hard disk production every year. If Tetrataenite synthesized by iron and nickel can be used as hard disk material, the consumption of platinum will be greatly reduced, thus promoting resource conservation and low-cost production of hard disks.
Chiharu Mitsumata (Toho Kyu University) of Tohoku University in Japan is carrying out basic research on the synthesis of Tetrataenite.
As a result, Dr. Koyama and Professor Sanyan won the second place in Dubose-Crouse Award (international metallic graphic contest) in 2010.
Dr. Masato Kotsugi Professor Chiharu Mitsumata
5. Successfully developed all-solid-state safety battery by nanotechnology.
Professor Hiroshi Kitagawa (Kyoto University) of Kyoto University and Dr Rie Makiura (Kyushu University) of Kyushu University have studied nano-scale silver iodide (AgI) particles. They proved for the first time in the world that it is possible to realize stable solid electrolyte at room temperature. This research achievement is highly valued because of its great development potential. The paper was published in the British scientific journal Nature Materials in May 2009.
6. the three-dimensional structures of Rab27B and Slac2-a are analyzed.
In 2004, Dr. Mitsunori Fukuda (Tohoku University) of the Graduate School of Life Sciences of Northeastern University clarified the transmission mechanism of melanin in melanocytes at the molecular level. In 2008, in cooperation with Shigeyuki Yokoyama of RIKEN Institute of Physical Chemistry, he successfully analyzed the three-dimensional structures of Rab27B and Slac2-a in BL41XU Experimental Station of Structural Biology on SPring-8. Their structural data will greatly promote the research and development of new skin whitening products and drugs to prevent white hair.
7. The new chewing gum Pos-Ca can effectively prevent tooth decay.
Dr. Tomoko Tanaka (the Health Science Laboratory of Ezaki Glico Co., Ltd.) found that calcium phosphate oligosaccharide supported the remineralization of teeth, which promoted the appearance of new chewing gum with calcium phosphate oligosaccharide (Pos-Ca).
Left: Tomoko Tanaka in SPring-8 Lab Right: New Chewing Gum.
8. Research and development of new drugs against influenza virus
Influenza virus consists of eight RNA genes, and there are two types of spike proteins on the surface of virus particles: hemagglutinin (HA) and neuraminidase (NA). Because of its simple structure, the virus cannot replicate itself. However, they can be skillfully replicated by using the replication system of human cells after invading human host cells.
HA, like a key, can invade the human body after combining with glycoprotein on the cell surface. NA plays an important role in the separation and release of progeny virus from cells, and is an enzyme that helps the virus infect other bacteria. The amino acids that make up the above two proteins are prone to mutation. So far, scientists have discovered 16 kinds of HA and 9 kinds of NA proteins. These protein are arbitrarily combined into various types of influenza viruses (H1N1–H16N9). For example, influenza A H1N1, which was prevalent in 2009, and H5N1 virus, avian influenza, which became prevalent in 1997.
Influenza virus encodes 10 kinds of proteins, among which RNA polymerase is very important in virus gene replication. It includes three subunits: PA, PB1 and PB2. When one of them is lacking, RNA polymerase loses its enzyme function and the virus cannot replicate. Therefore, if we can determine the three-dimensional structure of these three subunits, we can block the function of RNA polymerase.
In July 2008, Dr. Sam-Sam (Graduate School of Nanobioscience, yokohama city university) successfully analyzed the combined structure of PA and PB1, and analyzed the enzyme structure related to virus replication, which will accelerate the research and development of new antiviral drugs. It is not far away to realize the wish that people don’t have to worry about the flu in winter.
Left: schematic diagram of RNA polymerase subunit; bottom right: RNA polymerase subunit structure.
Top right: the complex of PA(239-716) and PB(1-81) was successfully crystallized, BL41XU, SPring-8.
9. Reveal the secret of solar system formation by analyzing comet dust.
The American Stardust Project, 1999-2007) collected scattered dust samples of comet Wilder II (81P/Wild) and brought them back to Earth. It is expected that by analyzing these samples, information about the origin of comets and the entire solar system 4.6 billion years ago can be obtained.
Dr. Tomoki Nakamura (Kyushu University) of Kyushu University has conducted in-depth research on comet dust. He used the X-ray diffraction experimental device of BL37XU on SPring-8 and the synchrotron radiation facility of KEK to analyze and determine the crystal types and abundance ratio of dust. After that, Professor Akira Tsuchiyama (Osaka University) used the CT scan of BL47XU to visualize the internal structure of comet dust.
Dr. Nakamura found that "meteorite chondrules" originated from comet dust outside the solar system, so they can no longer be explained by the traditional model of solar system formation. "Meteorite chondrules" are the main components of ancient meteorites, rich in magnesium, silicon and a small amount of iron. The doctor believes that the migration of "globules" occurred in the primitive solar system composed of dust disks; However, he said that the analysis accuracy of at least 20 samples will be improved to obtain statistically significant conclusions. He will also continue to carry out comet meteorite dating and determine the migration time. It is expected that a new solar system formation model will be established soon.
10. Nanotechnology promotes the innovation of "new materials"
The shape characteristics of fullerenes discovered in 1985-containing 60 carbon atoms, like a football-have aroused widespread concern in the scientific community. In 1991, columnar carbon nanotubes were discovered. In January, 2008, Associate Professor Kitura & Hisa Nori Shinohara (Nagoya University) of Nagoya University successfully synthesized a nano-scale metal wire.
Carbon allotropes: diamonds and graphite, fullerenes and carbon nanotubes.
Pure gold is prone to oxidation reaction, but a very thin nanowire can exist stably in the air because nano-scale materials have a unique stable structure. In order to observe the internal structure of nanotubes, Associate Professor Bei Puliang conducted solid soft X-ray spectroscopy experiments at BL25SU experimental station in Spring–8. He observed that the absorption of Er by X-rays was unique, thus confirming that ErCl3 line was formed in carbon nanotubes.
Carbon nanotubes in fullerenes look like pods.
ErCL3 structural model (Er atoms in red and CL atoms in green)
Professor Tian Zhuo (University of Tokyo/RIKEN) of Tokyo University and Institute of Physical Chemistry is regarded as the most imaginative and productive polymer chemist in the world. In recent years, he took SPring-8 as an important research tool, and first successfully determined the structure of a new type of conductive graphite nanotubes. Then, he showed with solid evidence that the hydrophilicity and hydrophobicity of graphite molecules were closely connected in hydrophobic groups, forming tubular spiral molecular pairs. In addition, he also successfully designed a liquid crystal phase with short intermolecular programs. Both research results were published in the Journal American Chemical Society in 2008. In 2009, the design of "bicontinuous cubic liquid crystal materials in discoid molecules" was published on the cover of the magazine of American Chemical Society, and he also won the Polymer Chemistry Award of American Chemical Society.
Professor Takuzo AIDA, a New Graphite Nanotube
11. Develop earthquake observation technology.
With the joint efforts of Tokyo Institute of Technology, Japan Agency of Marine-Earth Science and Technology and Japan Synchrotron Radiation Research Center (JASRI), it is found that the deepest part of the earth’s core is made of iron with hexagonal close-packed structure. The state of metallic iron under ultra-high pressure and ultra-high temperature conditions is similar to the state of the earth’s core simulated by ultra-high pressure and ultra-high temperature. Scientists used SPring-8 high-brightness X-ray to observe the changes of single crystal structure of metallic iron, and found for the first time that the hexagonal close-packed structure was stable under extreme conditions of high temperature and high pressure. The analysis of the crystal structure is helpful to the analysis of earthquake observation and greatly strengthens people’s understanding of the formation and development of the core. This achievement was published in the American journal Science on October 15th, 2010.
12. Analyze the gel mechanism of self-assembly from the molecular level.
Recently, a joint research group of The University of Kitakyushu and JARSI announced that the molecular structure of the solvent in the gel state was analyzed on the BL03XU Advanced Soft Materials and BL40B2 Structural Biology II Experimental Station by using SPring-8 high-brightness synchrotron radiation. The research results benefit from organogelator (low molecular weight compound). As long as 1% solvent is added to it, the whole solvent will gel, which will greatly help to prevent environmental pollution caused by offshore oil spill. The paper was published online in the October 2010 issue of Polymer Journal.
Sixth, look forward to the future
The resolution of traditional optical microscope is limited by the wavelength of light, while the wavelength of X-ray is 10,000 times shorter than that of visible light, and the resolution reaches the atomic level, which means that the three-dimensional structure of a single atom in matter can be observed. X-ray is widely used in medical treatment, life science and material science. However, the light generated by X-ray light sources (including synchrotron radiation) is not uniform and the wave fields are inconsistent. Laser can produce uniform light by using a pair of mirrors. This urges scientists to make every effort to explore a new technology to realize a mirrorless laser, that is, XFEL: X-ray Free Electron Laser (XFEL). XFEL is an X-ray that combines the characteristics of free-electron laser. It is called the most promising new light source in the future with the most scientific exploration and discovery value. It is also called "dream light source" and "new dawn of the scientific era". It has the dual characteristics of laser and radiation light, and can work in the whole X-ray band. It is much better than the third generation synchrotron radiation light source in brightness, coherence and time structure, and is internationally recognized as one of the feasible technical routes of the "fourth generation light source".
The United States, Europe and Japan have successively developed XFEL, and raised it to the height of national strategy to deploy and implement it. LCLS(Linac Coherent Light Source, Stanford Linear Accelerator Center, USA), the first X-ray free electron laser device in the world, came out in 2009. The European Free Electron Laser Facility (European XFEL) is jointly participated by DESY of Germany and 11 other European countries. The core project is a 3.4-kilometer underground tunnel, which was officially started on July 1, 2010. It is expected to be completed in 2014 and the first scientific experiment will be conducted in 2015.
SPring-8 has already started the prefabrication and research of XFEL, and the accelerator prototype has successfully produced the first laser beam. In 2006, the XFEL project started. At present, the 700-meter-long 8GeV X-ray free electron laser device is under final construction and is expected to be put into operation in fiscal year 2011. exist
Yellow area: accelerator and beam line research and development building, in which the accelerator test prototype is installed.
Red area: the location of SPring-8 XFEL device, a joint project of RIKEN and JASRI.
Bird’s eye view of SPring-8 XFEL
1. Milestone memorabilia
April 2000: Draft XFEL concept design: compact and low cost.
October 2002: The development of short-time high-magnetic vacuum undulator was completed.
December 2003: The electron gun was successfully developed, with the highest emissivity in the world.
November 2004: XFEL’s R&D team was formed.
January 2005: MEXT, the Ministry of Education, Culture, Sports, Science and Technology of Japan, reported on the future research and development policy of optical and photonic technology, and XFEL will be established as an important national scientific research project.
April 2005: Development of 250MeV test accelerator was started. The Liberal Democratic Party working group of MEXT, Japan’s Ministry of Education, Culture, Sports, Science and Technology, identified the new generation of synchrotron radiation light source as "an important key technology at the national level".
May 2005: XFEL User Committee was established.
November 2005: The first electron beam successfully passed through the test accelerator, and it was confirmed that synchrotron radiation was generated.
December 2005: The Japanese government allocated 2.3 billion yen from the 2006 national budget for the construction and research of XFEL devices.
February 2006: RIKEN and RSAC of SPring-8 Advisory Committee pointed out that the combination of free electron laser XFEL and large synchrotron radiation facility SPing-8 is unique in the world, so Japan should take the lead in the construction of XFEL.
April 2006: RIKEN and JASRI, a Japanese synchrotron radiation facility research institute, set up the XFEL project cooperation office.
June 2006: The laser oscillation of 49nm UV X-ray was successfully completed in the test accelerator, and the light was successfully emitted.
July, 2007: XFEL device was officially started.
March 2009: The accelerator building and the building where the undulator is located were completed.
April 2009: Installation of electron gun, accelerating tube and undulator began.
May 2010: The construction of the experimental building was completed.
2.XFEL facilities
SPring-8′ s X-rays can produce light 10 billion times brighter than the sun, while XFEL produces light 1 billion times brighter than SPring-8, and the pulse is 1000 times shorter than the existing X-ray source. The higher brightness light source enables scientists to observe the three-dimensional structure of atoms and their ultra-fast motion more realistically.
Design parameters:
Electron beam energy: 8 GeV
Electron beam diameter: 40 um
X-ray wavelength: > 0.06 nm
X-ray peak power: 5 GW
X-ray pulse length: < 100fsec
X-ray peak brightness: 1033 photons/s/mm2/mrad2/0.1% b.w. 。
The original quality of electron beam determines the quality of free electron laser. Scientists have specially designed an ultra-high voltage thermal electron gun, which uses a single-crystal cerium-hexabromoboride cathode (CEB 6) to emit a fine, highly collimated and stable electron beam. Then, it is transported into the electron beam compression system, and the peak current will be strengthened to several thousand amperes.
The electron beam energy is rapidly increased to 8GeV by a C-band linear accelerator, and then transported into a vacuum undulator to generate intense XFEL radiation.
Electron gun and CeB6 emitter
Left: linear accelerator and C-band acceleration structure right: vacuum undulator
C-band linear accelerator was developed by SPring-8 and KEK. C-band acceleration gradient (35MeV/m) greatly shortens the length of the accelerator. The total length was originally an accelerator structure with a precision of 1282mia and micron, and it was finally installed in a tunnel with a length of 400m.
C-band linear accelerator
Vacuum internal undulator
3. Create new technologies
Coherent X-ray imaging technology: Microscopic images of various materials at atomic level can be obtained.
Imaging process: X-ray laser → sample → coherent scattering mode → phase recovery → clear structure image.
XFEL’s ultrashort pulse can detect the ultrafast motion of matter in femtosecond.
Protein Structure Analysis: The analysis of new materials will surely lead to the birth of new functional products in biology and medicine.
Living cell biology: Real-time data acquisition will open a new way for the study of living cells.
Nanotechnology: Ultra-short wave XFEL will help to create new functional materials.
With XFEL, scientists can observe extreme phenomena in astronomy, plasma science and basic physics.
The Institute for Molecular Science, Niigata University, Nagoya University and JASRI/RIKEN of the National Research Institute of Japan jointly studied the intense ultraviolet free electron laser irradiated to argon atoms, and successfully analyzed the specific process of multi-electron emission.
In order to accurately measure the fluctuation in free electron laser, scientists analyzed all the electronic energy of argon atom irradiated by laser pulse at the speed of 20 pulses per second. They found that the absorption of electrons and multiphotons only occurs when the light intensity is very high, and clarified the importance of resonance state in multiphoton absorption. The research results show that the research of nano-science, nano-technology and material preparation can be promoted by using X-free electron laser on the basis of selecting appropriate laser wavelength and corresponding resonance conditions. The paper was published in american physical society’s scientific journal Physical Review Express on September 24th, 2010.
Chinese academy of sciences institute of high-energy physics scientific research Chu Chinese academy of sciences scientific apparatus office
The information comes from http://www.spring8.or.jp/en/.
