Video: Canadian Light Source goes dark for more stable light over the long haul
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The Canadian Light Source (CLS) at the University of Saskatchewan is replacing its linear accelerator (linac), the device that speeds up electrons to produce a beam of light researchers use to study materials at a molecular or cellular level. This critical replacement will ensure the CLS continues to deliver high-quality, stable and reliable light to the over 1,000 scientists from across Canada and around the world who use the CLS each year for research related to health, agriculture, environment and advanced materials.
Starting May 27th, 2024, the CLS will begin a six-month project to remove the existing linac and replace it with a new unit that will improve the efficiency and reliability of the light beam. For the latest updates, check back on this page or follow us @canlightsource on social media for #newlinac posts.
The latest news...
November 12, 2024: We have electrons in our new linear accelerator! Our staff have been working around the clock to prepare our new equipment and this is a major milestone in the linac project. This image shows our equipment detecting the first bunch of electrons generated from our new electron source. Our team then worked to get electron bunches further and further down parts of our linac. They successfully got a 42 mega electron volt (MeV) beam all the way to the end of the linac. This moment was duly celebrated by our staff in the control room! The next step is to get an electron beam with more energy (specifically, 250 MeV). We are happy to be that much closer to operating our synchrotron again.
October 28, 2024: We have two modulators (pictured) that provide radiofrequency waves to our linear accelerator (linac). These waves speed up a beam of electrons to just shy of the speed of light, which allows us to make synchrotron light for research. Typically, one modulator powers the first half of our linac and the second modulator powers the latter half. However, our new modulators can be configured to power the linac differently. Now one modulator can power the entire linac (at a reduced electron beam energy) or the modulators can switch which part of the linac they're powering. This offers greater flexibility and reliability for our synchrotron as it allows for maintenance to be completed on one modulator while the other continues to run and power our new linac. Our team is currently preparing the modulators to run in this configuration.
October 10, 2024: We are continuing to prepare our new linear accelerator (linac) to ensure it will create an excellent vacuum and be ready to receive billions of electrons from our electron source. During this past week, we needed to temporarily turn off the machine. After some machine checks were completed, we were able to resume heating up the #newlinac with radiofrequency power. We now have 17.5 megawatts of current running through the linac and climbing. That’s a 65 per cent increase compared to last week!
October 4, 2024: This week, we replaced an ion pump in the linear accelerator (linac) that wasn’t working properly. Ion pumps remove charged molecules from the linac to create a better vacuum. In order to make the swap, the linac had to be exposed to air. As a result, we had to carefully increase the power in the linac to protect the equipment. We constantly assess how the machine responds as we ramp up the power. Because some of the radiofrequency power gets reflected back onto the machine, we need to ease off temporarily. For this reason, the power in the linac can change hour to hour as we condition the machine for normal operations. We currently have 10.6 megawatts of power in the linac. This is a 430 per cent increase compared to last week!
September 27, 2024: Our staff are continuing to prepare our new linear accelerator by using radiofrequency power to heat up the machine and cook off any remaining impurities in our vacuum. We need to ramp up this power slowly to protect the equipment. If we increase the power too quickly, some of the energy can get reflected back onto the machinery and cause damage. Previously, we were up to 700 kilowatts. This week, we hit two megawatts, an increase of 186 per cent! We will carefully increase this power until we reach 36 megawatts, which is what our machine uses during normal operations.
September 20, 2024: Now that the new linac is in place, our focus shifts to commissioning. There are several stages of commissioning that need to be completed, but for now the RF structures are the star of the show. This phase of the upgrade actually involves three separate steps: cavity tuning of the RF structures, power balancing, and RF conditioning itself. Each of the five RF structures that make up the linac operate at a specific resonant frequency, or tune. Ensuring the tune is spot-on involves manually adjusting screws, physically pulling or pushing the cavity, or changing the temperature. While most of this was done in the factory, we may still need to make some micro adjustments here on site. Devices called power splitters ensure that each of the five RF structures gets its share of the power produced by our facility’s two modulators (photo). Last but not least, conditioning ensures that any remaining impurities not cleaned out at the factory are caught now. We heat up the waveguides and RF structures with a small amount of RF power to cook off any lingering contamination from the inner surfaces.
September 13, 2024:We are preparing our new linear accelerator (linac) to ensure it will create an excellent vacuum and be ready to receive billions of electrons from our electron source. Our team already thoroughly cleaned each component inside and out to help achieve a good vacuum level. However, we need as few molecules inside our linac as possible. To help achieve this, we are using radiofrequency power to heat up the linac and “bake” off any impurities still present. The power is slowly increased while staff monitor the machine. This week, we carefully ramped up to 700 kilowatts. During normal operations, the machine uses 36 megawatts.
September 5, 2024: Our staff are testing the equipment for our new linac to ensure that each piece is performing optimally. Electronic programs that monitor and control the linear accelerator’s operation are being developed and tested. Vacuum systems in the machine are getting inspected to ensure there are no leaks. The water pressure in the cooling systems are being verified. We are also checking that all the power supplies provide the appropriate voltage and current.
August 29, 2024: From the electron source to the modulators to the power supplies, everything that we use to operate the linear accelerator needs to be monitored closely and controlled electronically. Our team has started to set up work stations that enable us to operate the various pieces of the new linac from our control room (pictured at right). Since the new machine is so different, many of the systems we used previously will need to be updated or redesigned entirely. This requires collaboration between our vendor, Research Instruments, and our Controls and Instrumentation department. The staff who will use this system are also involved with this process, including accelerator physicists, radio frequency and high voltage technicians, and operators.
August 23, 2024:Years of work went into designing our #newlinac to ensure this machine will suit our specific needs. Its numerous components were special ordered and took months to years to arrive. Many of the parts were created for us by Research Instruments in Germany or were otherwise sourced from around the world. Once these pieces started arriving, space considerations came into play. We needed to find room in our facility for 63 crates that took up over 97 square meters of floor space. These numerous parts are now getting fine-tuned for operation in our basement.
August 16, 2024:Our facility is about the size of a football field and produces extremely bright light for research on 22 beamline stations. This requires a lot of electricity to operate. A great deal of our electricity usage goes into accelerating a beam of electrons to very close to the speed of light, which we then use to produce our light. Our new linac uses a high voltage power supply operating at 90,000 V – much higher than the ~12.5 V of a car battery! This 90,000 V is used to give the electrons their initial acceleration out from the electron source before travelling down the rest of the linac and being accelerated even further. This week, our staff installed a gate around this high voltage equipment (pictured). This is one of many safety measures to help keep our personnel safe.
August 8, 2024: This week, our staff have been getting the linear accelerator ready to create a high-quality vacuum. Our synchrotron consists of a network of pipes from the electron source all the way to the beamlines that operate under a vacuum. Without the vacuum, gas molecules in the pipes would become a giant obstacle course for the electrons, knocking them off their path, and we wouldn’t be able to provide bright light for our users. To create a vacuum in the linac, we use special pumps called turbo pumps (similar to the ones in the foreground in photo at right) to push air out until it reaches a very low pressure. Ion pumps then capture any charged atoms or molecules that are floating inside, achieving even better vacuum than the turbo pumps can do on their own. Once a vacuum is created, we check for any leaks where air might be sneaking in. There are many valves throughout the system that allow us to close off a particular section of the pipe while looking for or correcting a leak. Leaks are fixed by tightening connections, re-soldering joints, or both. Optimizing the vacuum for the whole linac takes time, as this involves testing and correcting dozens of components.
August 1, 2024: It's time! Our team has started installing one of the most critical pieces of the #newlinac: our new electron source. This piece of equipment initiates the electron beam we use to create synchrotron light for research. How will it provide electrons? Using heat. We will heat a beryllium-oxide plate inside the the electron source by running a large amount of electricity through it, much like an element on an old electric stove. Once it reaches a sufficient temperature, this causes electrons to “boil off” the plate.To eject electrons, the plate is set to a negative voltage that repels the electrons' natural negative charge. To control when electrons proceed down the linac, we place an electrified grid between the electron source and linac. This grid holds the electrons back until we want a pulse of electrons to proceed. This is similar to a dam holding back water. Once the electrons pass through the grid, they are guided to the linac where they will be accelerated to just shy of the speed of light.
July 25, 2024: Our team has installed most of the critical components for the #newlinac in our basement. Now that these pieces are in place, we need to get them ready for operation. One major step will be getting the system to create a high-quality vacuum. The vacuum removes as many particles as possible from the linac. Without it, the electrons in the linac would run into particles and not get to where we need them to create synchrotron light for research. Under normal operations, our vacuum is so effective that our machine has less particles than outer space near the international space station! In other news, our electrical technicians have been busy getting the linac Access Control and Interlock System (ACIS) up and running. Our facility takes many precautions to ensure we can provide a high-quality beam as safely as possible. The ACIS helps to keep personnel out of areas where elevated radiation could be present when the accelerator is operating. For example, it monitors whether gates (such as the one pictured at right) are open or closed. Without the ACIS, we wouldn't be able to use the new linac once it is ready.
July 18, 2024: Over the past week, our hard-working team has made substantial progress on installing waveguides and cooling equipment (pictured at right). Curious about what these pieces do? The linac accelerating sections that were installed last week form a long pipe with radiofrequency (RF) waves inside that transfer energy to the electrons, which accelerates them to just shy of the speed of light. The RF waves are generated by pairs of devices known as “low-level RF generators” and “modulators.” Our team installed new versions of these devices last month. The low-level RF generators create a small amount of RF power at a specific frequency that the modulators then amplify to make the waves more powerful. Waveguides direct these amplified RF waves to where they need to be in the accelerating sections. Every component involved in this process generates a substantial amount of heat. For this reason, we use cool water to keep the equipment from overheating or expanding.
July 11, 2024: Our team has started installing the accelerating sections of our #newlinac! This work is being done under the direction and supervision of our vendor, Research Instruments, who designed and built the linac system. They have come from Germany to Saskatoon to help with the installation. Installing a linac isn’t as easy as it sounds. Just getting the pieces into our basement is an undertaking. Our staff moved three 5-meter-long accelerating sections by crane into the accelerator hallway. (One of these sections is pictured at right.) The sections had to be tilted at a 60-degree angle in order to be lowered down the crane well. Our team had done a practice run earlier, to prepare for this tricky step. Now that the pieces are downstairs, they will need to be placed with precision. The gap between two of the accelerating sections has to be as close to 7094.535 mm as possible. Next, our staff will begin installing the rest of the components, including the electron source.
June 27, 2024: Last week, we installed the Medium Energy Beam Transport (MEBT) into the linear accelerator (linac) hall -- one of the first of many noticeable structures that we will see make their way down into the basement. But what is it? And why do we need it? As electrons travel down the accelerating sections, they tend to drift. To create the synchrotron light that we use for innovative research, we need magnets to help “shape” the electrons in a focused, stable beam as they exit the first accelerating section of the linac. The MEBT is made of 3 quadrupole magnets. Each of them has four poles that create a magnetic field that varies linearly with the position of the beam. That is to say, a particle in the center of the four poles will experience no field at all, while a particle at the edge will experience a strong magnetic field. This creates a focusing effect on the beam travelling through.
June 20, 2024: What a difference a fresh coat of paint makes! Our linac hallway is looking shiny and brand new. While the paint was being applied, our staff shifted focus to our modulator room. New modulators have been installed along with electrical cabinets. Once the paint had dried, work could continue with mechanical and electrical service installations for the #newlinac. The blue stands that will hold the new accelerating sections of the linac have been placed, aligned, and bolted down. Meanwhile assorted testing, measurements, and calibration have all been happening behind the scenes to prepare us for the installation of the linac itself.
June 6, 2024: With the old linac equipment removed from our basement, our health and safety staff needed to scan these pieces for radiation before they could be recycled or donated. They have now checked over 175 items! Next, we cleaned the linac hallways and started giving them a fresh coat of paint. Our staff also fully dismantled our modulator room. Klystrons, modulators, and other infrastructure were removed, making way for the mechanical and electrical service installation that is now ongoing. We have new modulators and klystrons waiting on our experimental floor. This equipment will provide the radiofrequency energy that is used to accelerate electrons through our linac before they produce synchrotron light for research.
May 30, 2024:The CLS has been dark for a short time, but there has already been a significant amount of progress thanks to our hard-working team. Once our operators turned off the machine, we soon started to dismantle the electron source and linear accelerator in our basement. Our staff have already removed the power supply tank, accelerating sections, and other assorted infrastructure. About 90% of the removed equipment will be recycled and the remaining 10% will be donated to universities or museums. The appearance of our basement has already changed dramatically. The linac hallways that are usually filled with specialized equipment are looking quite empty. While it may seem that this project has just begun, years of planning have led us to this point to help ensure the transition goes as quickly and smoothly as possible. Our team of engineers, technicians, physicists, and many others carefully prepared for when the key was turned for the final time and the six months of work that would follow. Installing a new linac will ensure the CLS provides high-quality, reliable synchrotron light for innovative research for years to come.
May 27, 2024: Starting today, the Canadian Light Source (CLS) at the University of Saskatchewan will begin work to replace its linear accelerator (linac) - the system that speeds up electrons to produce the ultrabright light researchers use to study materials at the molecular or cellular level. The new linac will replace aging infrastructure from the Saskatchewan Accelerator Laboratory that dates back to the 1960s and the early days of the CLS, and will enhance the facility’s efficiency and reliability. Over the next six months, staff will remove the old linac, its electron source and associated operating systems and refurbish the underground tunnel in which it is located. A new linac with a shorter and more modern design will then be installed, including accelerating devices, electromagnets, high-power radiofrequency transmitters, computer control system and ancillary systems, under the direction and supervision of the vendor, Research Instruments (Germany), who designed and built the system.Read more
