## Posts Tagged ‘R&D’

### Prototype of Mu2e solenoid passes tests with flying colors

Tuesday, August 11th, 2015

This prototype represents one of 27 modules that will make up a critical section of the Mu2e experiment, the transport solenoid. Photo: Reidar Hahn

If you’ve ever looked at a graphic of Fermilab’s future Mu2e experiment, you’ve likely noticed its distinctive, center s-shaped section. Tall and wide enough for a person to fit inside it, this large, curving series of magnets, called the transport solenoid, is perhaps the experiment’s most technologically demanding piece to build.

Last month a group in the Fermilab Technical Division aced three tests — for alignment, current and temperature — of a prototype transport solenoid module built by magnet experts at Fermilab’s Technical Division and INFN-Genoa in Italy.

The triple milestone means that Fermilab can now order the full set for production — 27 modules.

“The results were excellent,” said Magnet Systems Department scientist Mau Lopes, who is leading the effort.

There’s not much wiggle room when it comes to the transport solenoid, a crucial component for the ultrasensitive Mu2e experiment. Mu2e will look for a predicted but never observed phenomenon, the conversion of a muon into its much lighter, more familiar cousin, the electron, without the usual accompanying neutrinos. To do this, it will send muons into a detector where scientists will look for particular signatures of the rare process.

The transport solenoid generates a magnetic field that deftly separates muons based on their momentum and charge and directs slow muons to the center of the Mu2e detector. The maneuver requires some fairly precisely designed details, not the least of which is a good fit.

When put together, the 27 wedge-shaped modules will form a tube with the snake-like profile. Muons will travel down this vacuum tube. To guide them along the right path to the detector, the solenoid units must align with each other to within 0.2 degrees. The Magnet Systems team exceeded expectation: The prototype was aligned with 100 times greater precision.

The team achieved not just the right shape, but the right current. The electrical current running through the solenoid coil creates the magnetic field. The Mu2e team exceeded the nominal current of 1,730 amps, reaching 2,200 amps. As a bonus, while that amount of current has the potential to create a slight deformation in the module’s shape, the Mu2e team measured no change in the structure.

Nor was there much change in the model’s temperature, which must be very low. The team delivered 2.5 watts of power to the coil — well above what the coils will see when running. The module proved robust: The temperature changed by a mere whisker — 150 millikelvin, or 0.27 degrees Fahrenheit. The coils will be at 5 Kelvin when operating. The prototype sustained the nominal current at up to 8 Kelvin.

Fermilab has selected a vendor to produce the modules. Lopes expects that it will be two and a half years until all modules are complete.

“We thank all the smart people at INFN Genoa, the Fermilab Test and Instrumentation Department, the Magnet Systems Department and the Accelerator Division Cryogenics Department for this achievement,” Lopes said. “These seven months of hard work have paid off tremendously. Our project continues at full steam ahead.”

Leah Hesla

### New beamline at Fermilab Test Beam Facility delivers beam to LArIAT, a liquid-argon detector for neutrino research

Tuesday, May 5th, 2015

Technicians John Cornele, Pat Healey and Skyler Sherwin have been crucial in preparing the LArIAT detector for beam. The liquid-argon-filled detector saw first beam on Thursday. Photo: Jen Raaf

Fermilab’s Test Beam Facility (FTBF) now runs a second beamline to provide particles for R&D experiments. The MCenter beamline came back to life last year after an eight-year slumber to join the facility’s other beamline, MTest.

On Thursday, April 30, accelerator operators began using the revived beamline to send particles to its first major experiment, Liquid Argon TPC in a Test Beam (LArIAT), which will help advance particle detector technologies for neutrino experiments.

The FTBF provides experiments with different types of particle beams with a range of energies. Its main purpose is the research and development of particle detectors. It is one of only two sites in the world that provides this service with high-energy hadrons, which are particles made of quarks. Since 2005, the FTBF, with its distinctive orange and blue corrugated-steel roof, has staged more than 50 experiments, conducted by scientists from more than 170 institutions in 30 countries.

“We’re very busy and fully subscribed,” said JJ Schmidt, deputy facility manager at FTBF. “The existence of two beams allows us to serve a broader class of experiments.”

Not only does the new beamline allow FTBF to serve a larger number of users, it also provides room for a greater diversity of experiments. While MTest is aimed at experiments with a turnover of about one to four weeks, MCenter caters to more long-term experiments like LArIAT that will last for months, or even years.

Beautiful tracks at first try
LArIAT is a liquid-argon time projection chamber. Charged particles traveling through the sea of liquid argon ionize the argon atoms, and an electric field causes liberated electrons to drift toward the detector readout. Different particles cause different amounts of ionization, allowing researchers to distinguish between particles such as pions, kaons and protons.

This plot shows LArIAT’s first tracks: two views of a charged particle interacting inside the LArIAT detector, which is filled with liquid argon.

The first spill of particles delivered to LArIAT led to immediate success. The detector recorded picture-perfect tracks of charged particles.

Like the test beam, LArIAT will act as a research and development vehicle for future projects. Because neutrinos can be studied only through the particles produced when they interact with material inside a particle detector, being able to reliably characterize these other particles is of great importance.

“This is going to be fantastic not only for LArIAT but all the neutrino experiments that will use its results,” said Jen Raaf, co-spokesperson for LArIAT.

LArIAT will run the test beam for 24 hours a day while experimenters take data. The first run will last about three months, after which the detector’s cryogenic system will undergo upgrades to prepare for longer follow-up runs.

“It’s great that we have a facility where a small experiment can take beam over a long term,” said Brian Rebel, a scientist involved in LArIAT.

About 75 people from 22 institutions from the United States, Europe and Japan work on this experiment.

“Most are young postdocs and Ph.D. students that are enthusiastically doing a great job,” said Flavio Cavanna, LArIAT co-spokesperson.

“It’s an exciting combination of many years of work by the Accelerator, Particle Physics, Neutrino and Scientific Computing divisions to have the capability to do research that is important for making this the premier neutrino laboratory in the world,” Schmidt said.

Diana Kwon

### Sonic Copper Cleaning

Saturday, February 7th, 2015

Today we cleaned parts to go into the detector using a sci-fi piece of machinery called a “sonic bath”.

On CUORE, we’re looking for a faint signal of radioactivity. That means we can’t let anything swamp that signal: we have to clean away the normal low-level of dirt present in the atmosphere and biological systems. Even something as normal as a banana has so much naturally-occurring radiation that the “banana-year” is a (someone irreverent and imprecise) unit of measurement for backgrounds of dark matter experiments.

The parts we’re cleaning will be guide tubes for a calibration system. Through them, we’ll place wires close to the detector, then remove them again when it’s time for the main data taking. The calibration wires have a measured amount of radioactivity, and we use that known signal to calibrate the other signals within CUORE.

We used a sonic bath to clean the parts: they’re in a bag with soap water, inside a larger tub filled with tap water. To agitate everything (like the dasher in a clothes washer) the machine uses sound. It’s a bit like the little machines that some people use to clean their contact lenses, but larger: about the size of a laundry room sink, or a restaurant kitchen sink.

My favorite part of the process was the warning on the side: running with an empty bath could cause burnout of the ultrasonic coupler. “The ultrasonic coupler” sound like something out of science fiction: like a combination of “sonic screwdriver” and “flux capacitor”. But it’s not fiction– this is just what we need to do for our daily work!

The noise it makes sounds a bit like an electric fly zapper: a low level electric buzz and cackle, with a faint hiss hinting that there’s something higher pitched above that. It’s practically impossible to hear the main frequency because it’s pitched so much higher than human hearing: the noise is at 30-40kHz, and a child can usually hear as high as 20kHz. Some of the lower resonances fall into an audible range, which is what makes it sound like there’s more going on than I can hear.

In the smaller machine (about the size of a bathroom sink), the agitation noise was more audible, almost headache-inducing in long doses. Since I just watched the fourth Harry Potter movie, it reminded me of the recorded mermaid message: you can only hear it when you’re underwater. If you’re in air, it sounds like a screech instead of a message. Knowing the line between science fiction and fact, I didn’t actually stick my ear in the water (and we wore earplugs in the lab).

There’s a funny effect with some of the bubbles in the tub. They get caught in vibrational nodes within the water, so even though they’re clearly made of air, they don’t rise to the top. It’s like an atom trap made of lasers holding a single atom in place, except this works at a macroscopic level so it’s more intuitive. Seeing the modes in action is a little reward for having worked through all those Jackson problem sets where we deconvolved arbitrary functions in various ways.

When the parts come out at the end, and after we repeat the process with some citric acid (like what you find in lemon juice) and then rinse everything, the rods are a completely different color. They’ve gone from a dead-leaf brown to a peachy pink, all shiny and bright and hopeful. It’s a clean start for a new detector. We preserved the clean exteriors by sealing them in vacuum bags,  and told the chem lab supervisor we were done for the day.

### Mu2e attracts magnet experts

Wednesday, December 18th, 2013

By tapping into specialized knowledge around the world, the Mu2e collaboration will undertake a first-of-its-kind experiment. Image courtesy of Lawrence Berkeley National Laboratory

Fermilab’s Mu2e experiment is unlike anything ever attempted. So when the collaboration needed a first-of-its-kind magnet prototype built, they turned to an institution known for its magnet expertise: the Genoa section of the Italian Institute for Nuclear Physics, or INFN, located in the University of Genoa in Italy.

Earlier this year, INFN-Genoa became the sixth Italian institution to join the Mu2e collaboration, which now sports more than 150 members from 28 labs and universities in the United States, Italy and Russia. The team of magnet experts there has decades of experience working on high-energy physics experiments—they helped design and build magnets for BaBar at SLAC and, more recently, the CMS detector at CERN.

Now they’re putting that knowledge toward building prototypes of the years-in-development magnets that will be used for for Mu2e, an experiment intended to study whether charged particles called leptons can change from one type to another. According to Doug Glenzinzki, the deputy project manager for Mu2e, the experiment’s goal is to narrow down the possibilities for completing physicists’ picture of the universe, by amassing evidence for one theory over others.

“We know the Standard Model is incomplete,” Glenzinski says. “The number one goal of particle physics is to elucidate what a more complete model looks like. There are a lot of theories, and we are looking for data that tells us which is right.”

The Mu2e apparatus includes a detector solenoid, a transport solenoid and a production solenoid. Image courtesy of: Mu2e Collaboration

It turns out, Glenzinski says, “charged lepton flavor violation”—the phenomenon Mu2e is being built to study—is a powerful way of discriminating between possible models. Seeing this violation would also open up new questions about a theory of nature that has stood for 80 years. In short, this experiment could point the way toward the future of particle physics.

Mu2e will use a 92-foot-long detector with a unique design. It will be built in three sections, each its own superconducting solenoid, which is a set of electromagnetic coils that generates the particular magnetic fields required for the experiment. The detector consists of a production solenoid, a detector solenoid and a snake-like transport solenoid connecting them. Fermilab’s accelerators will fire a beam of protons into the production solenoid, where they will strike a target to produce pions. It’s the job of the transport solenoid to winnow down that beam of pions as it moves through, herding negatively charged muons to the detector solenoid and sending other unwanted particles out of the way.

The transport solenoid—a 42-foot-long curved pipe—will use 50 different magnets to accomplish this. The Genoa team will build prototypes of these magnets, working from years of design and engineering by Fermilab’s Technical Division, an effort led by Giorgio Ambrosio, Mike Lamm and Tom Page.

Pasquale Fabbricatore is one of the leaders of the Genoa team—he worked on both the BaBar and CMS magnets. He says that though the Mu2e magnets will use similar technology to large detector magnets, their unusually small size—about 6.5 feet in diameter—makes applying that technology tricky.

This sample holder is used to test the prototype conductor for the Mu2e experiment’s transport solenoid. Photo: INFN-Genoa Mu2e Collaboration

“Superconducting magnets are so particular that each one is a prototype,” Fabbricatore says. “Each unique magnet has unique problems.”

For example, Fabbricatore says, the prototype magnet will consist of a module containing two electromagnetic coils, installed close together through a shrink-fitting operation. While placing the first one should be easy, he says, warming the second coil up to the right temperature to install it without damaging the first could prove to be difficult.

“This is a problem we have never encountered before,” he says.

INFN-Genoa is just the latest Italian institution to join the Mu2e team. Glenzinski says the experiment has received strong support from Italy since the project’s inception. Italy is now contributing to Mu2e with four INFN groups from Frascati, Pisa, Udine and Lecce. It also leads the building of the calorimeter system, which helps measure the momentum of electrons and identify background signals. Glenzinski says the Genoa group makes a fine addition to a growing collaboration.

“Pasquale and his team are world-class magnet experts,” Lamm says. “They’re a great addition to the Mu2e collaboration and we’re excited to have them join us.”

The work on the new magnet began in September, and Fabbricatore says the prototype will be delivered to the collaboration in July 2014. Glenzinski says that fits the experiment’s timeline nicely. The collaboration will test the prototype, then send it out to a vendor to create the 50 magnets needed for the project. Assembly of the Mu2e detector should begin in 2016, with the experiment ready to take data by the end of 2019.

Andre Salles

### VERTEX 2012

Friday, October 5th, 2012

Never mind my complaints about travel, VERTEX 2012 was a very nice conference. There were a lot of interesting people there, mostly much more expert than me on the subject of vertex detectors. (I’ve written before about how tracking works and how a pixel detector works. In general, a vertex detector is a high-precision tracker designed to measure exactly where tracks come from; a pixel detector is one type of vertex detector.) My talk was about the current operations of the CMS pixel detector; you can see me giving the talk at right, and the (very technical) slides are here. Other talks were about future development in on-detector chip and sensor technology; this work is likely to affect the next detectors we build, and the upgrades of our current detectors as well.

The location of the conference — Jeju, Korea — was also very nice, and we got an afternoon off to see some of the island. The whole island is volcanic. The central mountain dominates the landscape, and there are lots of grass-covered craters. Sunrise peak, at left, erupted as recently as 5,000 years ago, but it seemed pretty quiet when we were there.

Overall, the conference was a great opportunity to meet people from all over the world and learn from them. And that’s really why we have to travel so far for these things, because good people work everywhere.

### Innovation at Fermilab: Liquid Argon Test Facility

Tuesday, January 24th, 2012

Despite the biting cold and snow, scientists and Fermilab personnel gathered outside to break ground for Fermilab’s new Liquid Argon Test Facility. The facility, expected to be completed spring 2013, will house liquid-argon based experiments.

Scientists have speculated since the 1980s that liquid argon could be used as a crash pad for high-energy neutrinos and have subsequently constructed several liquid-argon neutrino detectors; the largest and most prominent being ICARUS, the Imaging Cosmic And Rare Underground Signals, detector in Italy. The design of the new MicroBooNE experiment improves upon technology developed for ICARUS and will allow scientists to observe neutrinos with greater precision and resolution.

Regina Rameika is the project manager for the construction of the MicroBooNE detector.

“The MicroBooNE detector that will first use this facility is smaller than ICARUS, but incorporates some advanced designs,” Rameika said.

MicroBooNE will use liquid argon as a target for neutrinos generated in the Booster neutrino beam. When the neutrinos hit the argon nuclei, they generate showers of charged particles that then drift to an electrical detector. The purer the argon, the further the particles are able to drift. MicroBooNE will use ultrapure argon to maximize the distance these particles drift. This model is more efficient, cost effective, and has the potential to be scaled-up to a much larger size than previous detectors.

The MicroBooNE experiment will provide another layer of data for using the Booster neutrino beam. Not only will scientists be able to observe particles with the existing MiniBooNE detector, but now they will be able to measure neutrinos from the Booster neutrino beam with a second, higher-resolution detector.

“The MicroBooNE experiment will be focused on understanding some anomalies observed in the data from the MiniBooNE experiment,” Rameika said. This project will also provide valuable insight into different designs for liquid-argon detectors that could be located in the LArTF once MicroBooNE is complete.

—Sarah Charley

### Proton Accelerators for Science and Innovation

Tuesday, January 17th, 2012

This column by Fermilab Director Pier Oddone appeared in Fermilab Today on Jan. 17.

Last week we hosted the US-UK Workshop on Proton Accelerators for Science and Innovation. The workshop brought together scientists from the United States and the United Kingdom who are working on high-intensity proton accelerators across a variety of fronts. The meeting included not only the developers of high-intensity accelerators but also the experimental users and those involved in the applications of such accelerators beyond particle physics.

At the end of the conference, John Womersly, CEO of the UK’s Science and Technology Facilities Council, and I signed a letter of intent specifying the joint goals and activities of our collaboration for the next five years. We plan to have another workshop in about a year to review progress and explore additional areas of collaboration.

Our collaboration with scientists from the United Kingdom in the area of high-intensity proton accelerators is already well established. We have a common interest in muon accelerators, both in connection with neutrino factories and muon colliders. Both of these future projects require multi-megawatt beams of protons to produce the secondary muons that are accelerated. We collaborate on the International Muon Ionization Cooling Experiment at the Rutherford Appleton Laboratory. MICE is the first muon cooling experiment and an essential step in the road to neutrino factories and muon colliders. We also collaborate on the International Scoping Study for neutrino factories.

In our current neutrino program we are very appreciative of this collaboration and U.K. expertise in the difficult mechanical design of high-power targets, in particular for the MINOS, NOvA and LBNE experiments. The design of these targets is quite challenging as the rapid deposition of energy creates shock waves that can destroy them.The Project X experimental program also depends on having appropriate megawatt-class targets relatively close to experimental set-ups.

One of the primary interests in applications outside of particle physics is the development of intense proton accelerators that could be used for the transmutation of waste or even the generation of electrical power in subcritical nuclear reactors. The accelerators necessary for such subcritical reactors could not have been built just a decade ago, but the advent of reliable superconducting linacs changed that. Several programs abroad are developing such accelerators coupled to reactors. While the United States has no explicit program on accelerator-driven subcritical systems, the technologies that we are developing for other applications, such as Project X, place us in a good position should the United States decide to develop such systems.

Overall, the workshop was very productive and the areas of potential collaboration seemed to multiply through the meeting. Each one of the five working groups is preparing a brief summary of the potential areas of collaboration as well as a specific and focused plan for the next year.

### Successful beam test brings a muon collider closer

Tuesday, October 11th, 2011

A muon collider is closer to reality after a successful high-pressure hydrogen gas-filled RF (HPRF) cavity beam test at Fermilab. The test, conducted in the MuCool Test Area (MTA) at Fermilab by the MuCool collaboration, shows the beginnings of a practical solution to a difficult obstacle.

From left: Ben Freemire, Katsuya Yonehara, Mukti Jana, Moses Chung and Giulia Collura standing behind the HPRF cavity (under the hood) and beam pipe section. Photo: Yagmur Torun, R&D

“This was years in the making,” said MTA coordinator Yagmur Torun. “This idea of using HPRF cavities for muon cooling was first proposed in the early 2000s.”

Muons, a heavier version of electrons, are elementary particles. They cannot break down into smaller components, like protons decaying into gluons and quarks. Muons have nearly 200 times the mass of electrons. Electrons would lose too much energy circling in an accelerator, while muons retain enough energy to reach collision speeds.

The problem is that the muons come into existence as a hot gas, which is much too large to fit through a conventional accelerator without beam cooling.

Muons also do not live long enough to complete the acceleration if standard beam cooling methods are used. With only 2.2 microseconds to accelerate and collide, every instance of muon action must be carefully controlled. Ionization cooling is the only practical method that is fast enough for muons and the MuCool R&D program at Fermilab is aimed at developing components for muon cooling.

For muon cooling, RF cavities are used to accelerate particles within a strong magnetic field. The magnets help contain and focus the beam of particles. However, there were significant problems with the RF cavities, as scientists found that the cavities did not work well inside the magnets.

“The cavity would break down, or start arcing. It was unusable,” said Torun, assistant professor at Illinois Institute of Technology with a joint appointment at Fermilab’s Accelerator Physics Center (APC). “There were various ways to attack the problem, but then Rolland Johnson suggested we fill the cavities with gas.”

Rolland Johnson, a physicist who worked at Fermilab for 30 years and founded Muons, Inc., introduced the novel concept of filling the RF cavities with hydrogen. The hydrogen gas would suppress the electrons stripped from the cavity surface, which had previously caused the breakdown of the cavity.

The beam pipe leading into the solenoid magnet, with the HPRF cavity installed in the MTA experimental hall. Photo: Yagmur Torun, R&D

Physicists currently use RF cavities to bunch charged particles and move them forward through an accelerator. A standing wave, set at a particular frequency, pushes the beam particles forward to the next cavity.

“In 2005, we tested the hydrogen gas in the RF cavity,” Katsuya Yonehara, Peoples Fellow at the APC and spokesperson for the HPRF beam test, said. “The results were promising. We saw the cavity would work in a magnetic field, but we had a remaining question—could a very intense muon beam cause the field in the cavity to collapse?”

In 2007, a beam line from the Fermilab Linac accelerator was installed in the MTA. It took four years of adjustments and upgrades before the beam line was ready for the test in July of this year.

“It worked,” Torun said. “The cavity didn’t break down. This is a big step in our search for a potential path for muon colliders and accelerators at Fermilab.”

In the next few months, there will be a more detailed study.

“We’re adjusting the cavity, and making improvements for studying its application to muon acceleration,” Yonehara said. “We’re seeing progress.”

—Ashley WennersHerron

### Fermilab scientist receives $2.5 million award for innovative accelerator work Tuesday, August 16th, 2011 Fermilab issued this press release today. Alex Romanenko, sitting on the edge of a large cryogenic vessel, holds one of the superconducting RF cavities made of niobium. Photo: Fermilab (Click on image for larger version) Alex Romanenko, a materials scientist at Fermi National Accelerator Laboratory, will receive$2.5 million from the Department of Energy’s Office of Science to expand his innovative research to develop superconducting accelerator components. These components could be applied in fields such as medicine, energy and discovery science.

Romanenko w as named a recipient of a DOE Early Career Research Program award for his research on the properties of superconducting radio-frequency cavities made of niobium metal. The prestigious award, which is given annually to the most promising researchers in the early stages of their careers, includes a \$2.5 million award over five years to continue work in the specified area.

“Dr. Romanenko and his proposed research show great promise,” said Tim Hallman, associate director of the DOE’s Office of Science for Nuclear Physics. “We are pleased that he has been selected to receive an Early Career Research Program award to continue this work.”

Romanenko’s work could explain why some superconducting radio frequency cavities are highly efficient at accelerating charged particles to high speeds while others are not, as well as prescribe new ways to make cavities even more powerful. His research links t he performance of SRF cavities to the quality of the niobium metal used to make them. In particular, he investigates specific defects and impurities in niobium. Although scientists take painstaking measures to ensure that the niobium is completely pure and that the final SRF cavities are free from any contaminants, dust or debris, the cavities do not always perform the way that they should. Romanenko’s research is dedicated to finding out why that happens.

Romanenko began his research on SRF cavities as a graduate student at Cornell University, an institution known for its SRF research. He continued his award-winning work at Fermilab when he joined the laboratory in 2009 as a Peoples Fellow, a prestigious position given to scientists who have the potential to be leaders in their field. (More information at
http://www.fnal.gov/pub/today/archive_2011/today11-03-02.html )

Through his research, Romanenko found that a new, previously unexplored, type of defect near the cavity surface may result in surface differences that are responsible for a cavity’s inferior performance. What he found was surprising: the defect sites often contained niobium-hydrogen compounds, which might form when the cavities are prepared for operation. Specifically, he was able to pinpoint the problematic area to the first 40 nanometers of a cavity’s surface, a thickness equivalent to 120 layers of niobium atoms.

“The technology of these cavities has developed so fast recently that it is ahead of the corresponding science,” Romanenko explained. “We know how to make them work to a certain level of performanc e, but do not necessarily understand the full physics behind why they do so. I hope to understand why cavities behave in certain ways first, improve on this and then apply what I learn to other materials.”

If Romanenko can isolate the specific nanostructural effects that cause problems in cavities, then Lance Cooley, Romanenko’s supervisor and head of the new Superconducting Materials Department in Fermilab’s Technical Division, is prepared to direct other scientists to develop ways to prevent or control them and transfer that knowledge to industry. This could someday make it possible to mass-produce nearly perfect niobium cavities as well as lay the groundwork for cavities made from other superconducting materials that can perform at higher temperatures and accelerating fields. Such high-performance cavities—strung together to create powerful, intense particle beams—would lead to accelerators that can be used in indust ry, in hospitals and at research institutions. These accelerators are needed, for example, to produce a range of radioisotopes for medical diagnostics and have the potential to treat nuclear waste, among other applications. (More information at http://www.acceleratorsamerica.org/applications/index.html)

Strung together like the pearls of a necklace and cooled to ultralow temperatures, SRF cavities can accelerate particles with high efficiency. Photo: Fermilab (Click on image for larger version)

“This award recognizes the high caliber of research that takes place at Fermilab,” Cooley said. “It is because of the laboratory’s existing world-class research program that Alex’s research is likely to succeed.”

The monetary award will cover part of Romanenko’s research efforts, fund a postdoctoral associate and a part-time technician, and pay for advanced analysis techniques used to examine surfaces in the next five years.

Fermilab is a national laboratory supported by the Office of Science of the U.S. Department of Energy, operated under contract by Fermi Research Alliance, LLC.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov

### Power to the cryomodule: accelerator tech gets jolt

Tuesday, August 2nd, 2011

Editor’s note: Fermilab has been working with national and international institutions to develop superconducting radio-frequency cavities and their encapsulating cryomodules for next-generation accelerators, including the proposed International Linear Collider and the proposed Project X.

CM1 with its recently installed RF distribution system ready for testing. Image: Jerry Leibfritz

SRF technology enables the acceleration of intense beams of particles to high energies more efficiently and at lower costs than other technologies. SRF technology could also be applied in the areas of clean nuclear energy and transmutation of radioactive waste.

Cryomodule 1 is now firing on all eight cavities.

Cryomodule 1, Fermilab’s test cryomodule for ILC-type accelerating cavities and superconducting radiofrequency (SRF) technology, was powered up as a complete, multi-cavity instrument earlier this month. Previously, researchers had delivered power only to the individual cavities inside it.

“We’ve operated superconducting cavities before, but this is the next step in scale,” said Sergei Nagaitsev of Fermilab’s Accelerator Division. “Operating a single cavity in its own cryostat is comparable, but with a full cryomodule, the complexity goes up by an order of magnitude.”

Since the cool-down of CM1 last November, scientists and engineers have been busy installing the plumbing for power distribution, called waveguides; upgrading the water skid, which helps with the cooling of the high-power RF equipment; and taking data on each cavity’s accelerating gradient and quality factor, or Q. Researchers completed the cavity tests in June.

“The big question now is how this module performs compared to when the cavities were at DESY,” said Fermilab’s Elvin Harms. The German physics lab DESY provided all eight CM1 cavities, which were tested before they came across the Atlantic. Over the coming weeks, researchers will continue to feed power into cryomodule to gather data on how cavities perform as a single unit rather than as individual elements. The hope is that their gradients and Q will be in reasonable agreement with DESY’s numbers.

To make sure the data that comes through is reliable, the CM1 team will work on calibrations, test RF power operation, and work the kinks out of the system. Then comes a multi-week programme where scientists will perform stability tests and beam studies for the ILC beam current programme, which includes tests that can be conducted without the presence of beam. Researchers will also use CM1 for tests for Project X, Fermilab’s proposed proton accelerator programme.

Not all sailing was smooth in the time since the November cool-down. Some cavities still have wrinkles that need to be ironed out.

“Nevertheless, the fact that the integration of it all into a single system worked is a tremendous boost for the Accelerator Division, the Technical Division and our collaborators,” Nagaitsev said.

Collaborators on CM1 include researchers from DESY, INFN in Italy and KEK in Japan.

“Many people have invested a lot of time in CM1,” Harms said. “They’ve been eagerly waiting to get this to this day.”

— Leah Hesla