Technology at NSCL

Imagination, creativity and scientific knowledge are the lifeblood of nuclear physics research, but the equipment is the skeleton that brings form and substance to science. NSCL long has been at the forefront of developing technology that makes nuclear science a reality.

Schematic diagram of an Electron Cyclotron Resonance ion source.

The journey to scientific discovery at NSCL begins with its ion sources. Particle accelerators use electromagnetic fields to accelerate and direct elements. But first, these need to be electrically charged – or ionized – by the removal of electrons. At the lab, this is done with Electron Cyclotron Resonance (ECR) ion sources, which provide the ionized nuclei for the cyclotrons.

NSCL has two cyclotrons that are connected to boost both of their power. The first is the K500; the very first superconducting cyclotron ever made. The second is the K1200, which is the second most powerful accelerator of its kind in the world. In addition to these two behemoths, the lab has in

the past produced small cyclotrons for hospitals including the K100 for neutron therapy and the K250 for proton therapy. Both are used in advanced treatments of cancer.

After the cyclotrons get the nuclei up to speed, they send them to one or several of the unique experimental devices designed and built specifically for its job. These devices include chambers for smashing the nuclei apart, separators to find the interesting fragments,

neutron detectors, beta-ray detectors and even traps capable of stopping and suspending rare isotopes for experiments. To learn more about each aspect of the lab and how it all fits together, browse our online Interactive Map. Then, if you want more detailed information, scroll through the descriptions below to learn about each and click on the photos for expanded descriptions.

These devices need many similar components to make them work including magnets, cryogenics and electronics. The magnets in use include dipoles that – like refrigerator magnets – are placed to attract one another. Quadrupole magnets create a narrow tunnel with magnetic fields that compress and direct the rare isotope beams. Many of these magnets are much stronger than the entire Earth’s magnetic field and require superconducting wire to be kept at -452 °F.

In order to keep these wires – and other components – at such low temperatures, the lab also must be an expert in cryogenics. The mechanism for cooling is the same effect used when boiling potatoes. At its boiling point at one atmosphere of pressure, water maintains its temperature at 212 °F. Even though the flame under the pot is much hotter, the potatoes don't burn because the water boiling away maintains constant temperature.

Superconducting quadropole magnet is wrapped with aluminized mylar foil to reduce heat loss.

In the case of superconducting wire, we use liquid helium boiling in the pot holding the magnet. The boiling helium maintains the magnet temperature at -451.6 °F. At this temperature, the wire stays superconducting and a strong magnetic field can be maintained using little electric power. This is the reason for using cryogenic technology; magnets can be more compact and cost less to operate.

Of course, none of these systems would work without the proper electronics. High performance power supplies, sensitive instrumentation, dynamic systems controls, supervisory controls and high powered radio frequency systems to accelerate nuclei all are built at the lab.

For example, power supplies that put out 1600 horsepower, power sources that regulate current output to within five parts in a million and current meters that can accurately read as low as 30 picoamperes, are all in a day’s work.

And of course, none of this equipment can be obtained simply by walking down to the nearest Walmart or Lowes. Just like Thomas Edison couldn’t pick up new filaments or glass bulbs around the corner to try out his light bulb idea, NSCL scientists must make most of their equipment themselves. This is why the lab has crack mechanical design and fabrication and assembly teams.

The inclusion of 2D and 3D computer aided modeling on all new equipment designs allows all of the complicated parts to be solid modeled and produced by direct transfer of CAD data to the fabrication machine center. The combination of decades of experience in ion beam related technologies and the concerted effort to integrate computer-aided systems into our processes puts NSCL at the forefront of providing mechanical engineering and design services for nuclear and accelerator physics research.

Our machine shop utilizes six computer numerical control milling machines and three lathes – one with live tooling – which are equipped with PC based controllers. Training programs have been developed and designed to enhance machinist skills in CAD/CAM technology. Keeping a machine shop equipped with up-to-date technology complements the design capabilities of our mechanical design department and outside users at NSCL.

Graphical display of a nuclear collision. The collision was recorded with the NSCL data acquisition system.

Finally, none of these fancy gadgets would work correctly if there weren’t software to support it and capture the data being created. The control system is a collection of networked computers and distributed hardware and software that allows our operators to remotely control the many devices that make up our ion sources, cyclotrons, beam lines and auxiliary equipment. In fact, there are more than 18,000 device channels in the existing control system. The majority of software used by our operators to control the facility is developed here at NSCL.

Once the pieces are all working together, experimental data can be gathered. Each collision that generates a signal marking it as interesting triggers the collection of data related to that event. Since each experiment can collect different data for each collision, our data acquisition system must be very general. As data are taken, online analysis programs access them to ensure that the experiment is working properly.

All in all, NSCL is pretty self-sufficient. The lab has the knowledge to design new instruments, the experience to build them and the ingenuity to control them.