Michigan's MoNA LISA

There are many masterpieces of the world hidden away in the strangest locations. From Greek statues to Michelangelo’s Sistine Chapel, these works of art are both admired and well known. What many may not know is that such a masterpiece lies in wait on Michigan State’s 5200-acre campus in East Lansing, Michigan.

The MoNA LISA.

Not to worry, as the Louvre is not missing one of its most famous and coveted pieces by Leonardo da Vinci. Instead, MSU is home to a very special detector with a very long name - The Modular Neutron Array and the Large multi-Institutional Scintillator Array, or MoNA LISA for short. A part of the National Superconducting Laboratory (NSCL), these detectors help scientists explore rare isotopes while also providing a unique experience for undergraduates - not only helping to maintain them, but to participate in the MoNA LISA’s research. And what could be more fun than creating strange particles and smashing them?

Creation
Undergraduate colleges and students have been fortunate to be a part of the MoNA LISA project since its inception, though it almost didn’t get off the ground. Initially priced at $1 million, MoNA’s price tag was too steep for MSU’s pocketbook and faced fierce competition from other national laboratories for federal funding. Luckily, MoNA’s creators found a way around that.

Noticing undergraduate colleges listed as collaborators, the National Science Foundation explained they had money earmarked specifically for undergraduate schools. Thus the original proposal was scrapped for nine smaller proposals and funding was granted to each undergraduate college. With this grant money each college was then tasked to build one layer each of the detector.


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The MOdula Neutron Array (MoNA) and the Large multi-Institutional Scintillator Array (LISA).

Made up of multiple layers of detectors, MoNA is stacked similar to legos or building blocks – each layer functions on its own and can be moved. From ensuring each scintillator was light-tight to attaching photo-mulitplier tubes, undergraduate students played a vital role in making MoNA a reality.

Completed in 2003, each layer was transported to the NSCL and assembled by faculty and the students who helped create them. As da Vinci refused to be parted from his beloved painting, the undergraduates who had poured their time and effort still wanted a chance to continue working with MoNA. Thus undergraduate experiments took off. Hands-on experience doing cutting edge science at a national laboratory are many undergraduates’ dream come true. Over the years more colleges were added to the collaboration and, naturally, undergraduates were involved in helping scientists make LISA a reality when it was commissioned in 2010. With two detectors now available, a wider area was obtained from which to gather data, leading to many more experiments.

How it Works
In many ways, the detectors provide a mini-mystery that is solved by working backwards. As neutrons have no charge there is really no way to create a device that would detect them – at least without help from a charged particle.

General more: To start with, imagine a conveyor belt filled with cupcakes, which represents a nucleus, that is covered in sprinkles, which represent neutrons and protons. At the end of the conveyor belt is a panel that the cupcakes bump into. Due to the force, some of the sprinkles fall off, creating a completely new type of cupcake, or isotope, and the cupcake continues on its way. In essence, these different types of cupcakes are what the MoNA LISA project studies; smashing isotopes apart to produce new ones.


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The powerful Sweeper Magnet that deflects positively charged particles and nuclei away from MoNA LISA.

After the isotope loses some of its neutrons, it gets carried away by a powerful magnet, while the neutron is able to fly free into the detectors. The detectors themselves, if you were able to see inside, could be thought of as a lightning storm. When the neutrons hit a particle in the detector, light is emitted. The detector’s job is to time this light, and see how long it takes to be picked up on either end. Just like children count down the seconds between a lightning bolt and thunder, the detectors do the same thing. From this reading, scientists are able to figure out exactly where the neutron hit, its flight path to get to the detector, and how long it took. A particular example that has been done through the MoNA LISA project is the Beryllium-16 experiment.

An isotope beam of boron-17 is produced before being broken apart into beryllium-16. Unfortunately for the scientists that wish to study it this isotope is unbound and has a very short lifespan before decaying into beryllium-14 and two neutrons. The charged Be-14 is attracted and ‘bent’ in a new direction while the neutrons ‘fly’ in a straight line and interact with MoNA LISA.


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A computer rendering of what the light detectors at the ends of the individual modules that make up MoNA LISA look like.

This particular experiment belongs to an overall theory about how neutrons can possibly break away from an isotope. For instance if they break apart one at a time, or if two neutrons leave together (sometimes known as a dineutron). Just as the possibilities of Mona Lisa’s true identity are endless, multiple possibilities of neutron decay exist for all isotopes. While there is not yet a guaranteed way to predict how and why neutrons will scatter in a particular way, experiments such as these bring us one step closer.

The Full Undergraduate Experience
Conducted during the summer, these undergraduate collaborations that started by building the detectors evolved into actual research. From maintaining the equipment through repairs and calibrations, to collecting, manipulating and analyzing data, undergraduates get to experience a little bit of everything. Working shifts with graduate students and faculty, undergraduates bring a set of fresh eyes that can sometimes pick up new data by simply asking, “What is this?”.

While video conferences are available for those students who are still offset, the most rewarding and effective research comes from being able to physically be at the NSCL. “It’s a great opportunity to have students get their hands dirty,” Jenna Smith, a graduate student working with MoNA LISA explains. “It’s a place where you can screw up, and have people not only fix it, but explain what happened.” In return, undergraduates have a way of asking questions that lead graduate students to gain not only a better understanding of their field, but also give them a place to practice teaching their specialties. This symbiotic relationship in an actual laboratory can lead both undergraduate and graduate students toward careers as professors at different colleges - colleges that tend to wind up as collaborators for new projects.


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The floor plan of the room that houses MoNA LISA.

As each new wave of undergraduates and graduate students come and go, the faculty help provide the continuity for such collaborations to be encouraged and continued, hoping to gain more colleagues for their field.

As undergraduates continue to flood the MoNA LISA collaboration, they are a key element that allows NSCL to continue to be a leader; not only in scientific study, but also as a place undergraduates can get their ‘feet wet’ with real laboratory experience. By providing this rare opportunity, MoNA LISA showcases itself as a true masterpiece of science.

Written by Rachel Little

Many thanks to Thomas Baumann and Jenna Smith, for providing information and pictures.