Synchrotron light is an electromagnetic wave similar to sunlight. However, synchrotron light is the electromagnetic wave radiated from a charged particle such as electrons moving at velocities near the speed of light. Forced to change direction by actions of an magnetic field, such electrons then lose a certain amount of energy and discharge in the form of electromagnetic waves called “synchrotron light.”
Did you know that … electromagnetic radiation is the transverse wave consisting of magnetic and electric fields perpendicular to each other? The electromagnetic field can traverse without a medium such as radio waves, microwaves, infrared, x-rays, etc.
There are several types of light that can be found on earth, such as the sunlight during the day time, the light from stars at night, light from light bulbs or even from animal sending their signals such as fireflies. Such lights are either natural or man-made lights. Did you know that there is another type of light that has special unique characteristics from any the other light aforementioned? This light is over a million times brighter than daylight. Its beam of this type of light is merely in the scale of micrometer (1 in 1,000,000 meter). The wavelength of such light ranges over 4 wavelengths, namely, infrared, visible light, ultraviolet and x-rays. Scientists call this type of light the “synchrotron light.”
In Thailand, there is an institution with the capacity to produce synchrotron light for ananlysis, research and value added product improvement and development called the “Synchrotron Light Research Institute (Public Organization).” Situated at Suranaree University of Technology, Nakhon Ratchasima Province, it is the one and only institution in Thailand and the largest in ASEAN region. The synchrotron light source machine is a large scientific apparatus with complex engineering technology which is fundamental for the scientific and technological development of the country. It responds to in-depth material-related questions down to the atomic and molecular levels with applications ranging from agriculture, medicine, pharmacy and industry.
Synchrotron Light Research Institute is a public autonomous organization, under the Ministry of Science and Technology. Its mission is to conduct research related to synchrotron light, provide synchrotron light services and technology, and promote understanding and learning related to synchrotron light technology. The institute has carried out all its missions following the royal initiative of HRH Princess Maha Chakri Sirindhorn to add economic value, enhance the quality of life of Thai people to international level.
In addition, the institute is determined to carry out its operations according to the government’s national development policy, which is to create research which caters the industry to help propel national economic growth.
The light obtained from the synchrotron light source is of great use for in-depth scientific research analysis of various materials to the atomic and molecular scale. The materials to be tested can be in the form of solid, liquid, gaseous or even plasma. The synchrotron light source is therefore a fundamental scientific and technological element for the national development of industry and economy. It is also an index indicating the progress in science and technology of the country.
The synchrotron light produced at the Siam Light Laboratory is 1 million times more brighter than the light from the Sun. It has a sharp beam, high intensity with great penetration capability and a beamline as thin as human hair. Therefore, it can be used to study the atomic structure of various elements. Furthermore, its wavelength covers a continuous range from infrared rays, visible light, ultraviolet rays and x-ray, thus providing scientists the ability to select suitable wavelengths or energy for use in their research.
1. Electron Gun
Electron Gun produces a tremendous amount of electrons by applying electricity to heat up the cathode of the electron gun until the electrons are released. Then high positive voltage is applied to pull the electrons into the linear accelerator.
2. Linear Accelerator : Linac
The linear accelerator divides the electrons released from the electron gun into groups called electron bunch, which linear speed is then accelerated by microwaves to attain 40 Mega electron volts (40 MeV). The electrons are then fed into the booster synchrotron.
3. Booster Synchrotron
The booster synchrotron increases the electron energy in a circular motion by radio waves. To accelerate electrons to the desired high energy by only a linear accelerator would require a length of several kilometers. However, scientists have come up with a circular accelerator which force the electrons to move in a circular pattern and accelerated until the electrons reaches a balmy energy level of 1,000 Mega electron volts (1 GeV) in 0.6 seconds or almost reaching the speed of light. The electrons are then transferred into the storage ring at the final stage.
4. Storage Ring
The storage ring increases the electron energy to reach up to 1,200 million electron volts (1.2 GeV). The ring consists of various types of magnets including dipole, quadrupole and sextupole magnets which are used to force these high energy electrons to move in a vacuum tube. The energy which is released in the form of electromagnetic waves occurs in the bending magnet segment is called “synchrotron light.”
5. Beamlines: BL
The beamline system forms beamlines and selects the desired range of synchrotron light created from the electron storage ring to the experiment station. The beamline system consists of a vacuum, collimating mirror, monochromator, focusing mirror, slit and other miscellaneous components. At the end of the beamline system is the experiment station where a signal measurement system is installed for specific technical experiments for further research use.
Insertion Devices In producing synchrotron light, the light intensity and energy level desired by scientists require the installation of insertion devices at the synchrotron light source. There are typically 3 types of insertion devices used at the Siam Photon Source which include
Undulator consists of numerous dipole magnets interleaved with the magnetic field perpendicularly aligned with the movement of electrons. The numerous magnets forces the electrons to bend many times. Each round, the electrons release synchrotron light which is then collected forming a beamline to the experiment station. Therefore, such insertion device increases the intensity of the synchrotron light.
Superconducting wavelength shifter (SWLS) is another type of insertion device which uses fewer dipole magnets than the undulator, but with higher magnetic field intensity which forces electrons to bend more sharply. The resulting beamline from the wavelength shifter has greater energy compared to dipole magnets or the undulator. To produce a high intensity magnetic field, a superconductor induction coil is required. At SLRI, a 6.5 Tesla magnetic field can be created to produce hard x-rays.
Multi-pole wiggler (MPW) is a permanent multipole magnet used to increase the energy of the synchrotron light required to produce high energy x-ray which has a frequency near that of the gamma ray.
1. The first step is to produce electrons by means of applying electricity into a cathode of an electron gun until it is so heated that electrons are released. Then high positive voltage is applied to pull the electrons to move in the same direction.
2. The second step is to accelerate the linear speed of the electrons using a linear accelerator or (LINAC). The purpose is to accelerate electrons to the desired velocity (40 Mega electron volts). The electrons are then fed into the booster ring or the synchrotron.
3. In the third step, the electrons in the synchrotron are forced to move in a circular pattern and accelerated until the electrons almost reach the speed of light (1,000 Mega electron volts or 1 GeV). Then the electrons are then transferred into the storage ring at the final stage.
4. In the fourth stage, the storage ring increases the electron energy to reach upto 1,200 million electron volts (1.2 GeV) to produce synchrotron light using magnetic field to change direction and emit light or photons and store the electrons produced. The synchrotron light is then used and provided to scientists for their various research.
1. Fundamental science
Synchrotron light can be used in basic research in discovering atomic and molecular properties and the length of the bonds between atoms in molecules of matter, the study of property changes of materials under high pressure and temperature, the study of certain magnetic properties and the study of arrangement of atoms on the surface and toxic residues in the environment due to its capability of accurately discovering trace elements.
2. Research in biological and medical science
Synchrotron light is an essential element in the study of bio molecular matters with small and complex structures commonly found in living beings such as proteins, nucleic acid, etc. Examples include the study of three-dimensional structure of proteins using the Protein Crystallography technique, which can be applied in the industry to design medicine ingredients, or the Infrared Microspectroscopy technique to classify stem cell, etc.
3. Industrial research
Research study to develop new products or improve existing products require in-depth studies by applying new knowledge to add industrial value. As synchrotron light energy covers a spectral range from infrared ray to x-ray, it can cover ranges from nanometers to micrometers which are micro particle size of materials widely studied particularly in advanced industrial development.
With its many properties, synchrotron light can be used in many applications and add value to products, economy to the country. Examples include
Frozen shrimps development
CPF Company is one of the forefront companies in the country exporting frozen fruit generating significant revenue to the country. In 2014, CPF approached the Synchrotron Light Research Institute a research problem related to exported frozen shrimps which have been in prolonged storage period. It was found that small white spots appeared on the shells on the products stored in subzero temperatures. During the time, CPF conducted their own study and research on the matter, however, a solution was yet discovered.
The Synchrotron Light Research Institute contributed in their research and found that the white spots were in fact calcium in the shells of the frozen shrimps under prolonged subzero temperature formed from calcification as a result of water loss. The research finding thereby helped CPF increase economic value to up to 1300 million baht per year.
Solution to Hot Rolled Steel Sheet Problem
SSI is Thailand’s first comprehensive manufacturer of hot rolled metal sheets in coil and steel sheets and the largest manufacturer in ASEAN region. During the manufacturing process, it was found that about 30% of their coils had wood grain patterns. The company conducted their own extensive preliminary research but did not discover the solution to remove the pattern. SSI research team therefore brought their problem to consult with the Synchrotron Light Research Institute for joint collaboration. Using X-rays of synchrotron light, it was discovered that the wood grain were caused from residual chemicals on the rolls during the manufacturing process. Once such chemical residues were removed, the wood grain patterns were eventually eliminated. The success led to further collaboration between SSI and the Synchrotron Light Research Institute. Recently, the institute analyzed the causes of dark-colored metal and methods to recover the natural metal color.
Plastic Grain Development
SCG Chemicals Company is a company with progressive research. The company recently developed and improved plastic grain for molding products according to customers’ requirements. For such plastic grain development, the company required molecular scale analysis to confirm the quality improvement in each their products. This led to international journal publications which is an alternative quality assurance of their plastic grain.
Cassava is Thailand’s economic crop which at the end of its processing stage, leaves residual waste which has been typically eliminated or turned in to livestock feeds. Recently, cassava processing companies have investigated ways to transform such cassava waste into various raw materials to add value, such as, mixture in supplementary food for patients. Another company transformed the cassava waste into soluble fiber used as weight-controlled food. An additional research transforms cassava waste into surfactants for pharmaceutical use which controls the release of medicine in the body and thereby controlling the active period of medication.
With crime problems arising at present, means to uncover and bring real criminals to justice in the court of law is therefore crucial. In particular, the collection of evidence for prosecution must be apparent as in developed countries such as Japan, Europe and USA. Scientific and technological knowledge can thus be used for accurate forensic applications.
Synchrotron Light Reveals Evidence of Arsenic in Curry Pot to Convict Housewife of Mass Murder in Japan
In 1998, a gruesome crime was committed at Wakayama District in the western part of Japan. Ms. Masumi Hayashi a 47 year old housewife, who was raged being shunned off by neighbors, took revenge by poisoning a pot of curry distributed at a local festival. Four people were killed and over 60 people were treated with acute poisoning. Following the Hayashi denied all charges. The police report stated no finger prints of the suspect were found and that the evidence was circumstantial as only kitchenware was found. No traces of arsenic or any links were found from typical forensic tests in the laboratory because Hayashi’s husband who is a painter also uses paint containing arsenic. Having helped her husband clean arsenic off his equipment, Hayashi used this technique to remove the substance off her kitchenware. Then scientists with synchrotron light and metallurgical expertise pointed out that arsenic, when combined with metal, changes its molecular structure which is why the substance cannot be detected by typical forensic tests. These scientists therefore requested the evidence to be tested with synchrotron light. It was found that all Hayashi’s kitchenware were contaminated with arsenic. Hayashi was thus sentenced to death.
Unveiling the Phar Lap Horse Mystery with Australian Synchrotron Light
Phar Lap was one of the world’s greatest race horses (1926 – 1932) which captured the hearts of the public in Australia and New Zealand with its streaks of wins in every race. At the time, offers to bribe the Phar Lap were strictly turned down by the owner and the jockey. Phar Lap was thus targeted by gamblers and was even attempted shot at twice by rifle but survived. However, in the last incident, Phar Lap fell mysteriously ill in its own stable with symptoms of excessive saliva. An autopsy by a veterinarian revealed that Phar Lap’s internal organs were inflamed, swollen and stopped functioning. However, the cause of death was unclear. After its death, Phar Laps skin, skeleton and heart were stuffed and exhibited as taxidermy mount displayed at various museums in Australia and New Zealand. In 2000, a group of scientists analyzed the cause of death and stated that Phar Lap had suffered acute septicemia. However, later in 2006, Australian scientists used x-ray synchrotron light to reexamine 6 hair strands of Phar Lap’s mane. Traces of arsenic were found and it was thus concluded that the horse had been poisoned. It was also discovered that the arsenic molecular form from stuffing were clearly distinguished from the ingested arsenic in the bloodstream. Easily accessible in the past when mining was popular, arsenic can be purchased from drugstores or chemists.