Walsworth Group: Hard at Work

The NMR-research side of the group is inherently multi-disciplinary and multi-institutional. As we have not, until December 2003, had space to locate our own NMR/MRI instrumentation at the Center for Astrophysics, we've trekked across Boston and further afield in search of collaborators who are willing to participate in laser-polarized noble-gas NMR research projects utilizing their NMR equipment. In Boston, we've worked at Brigham and Women's Hospital (BWH), Massachusetts General Hospital, and MIT; while our travels have reached as far afield as University of New Hampshire in Durham, and Schlumberger-Doll Research, in Ridgefield, CT.

We're now rationalizing our space (and travel!) and will be erecting our own high field vertical bore NMR system and ultra-low-field open-access human MRI system in our own lab space at 60 Garden St. Collaborations are continuing with BWH and MIT, however, so we're still likely to see more scenes of noble-gas polarization equipment hitting the road, leaving the CfA for BWH or MIT, and even University of Massachusetts Amherst in the future. At left, Matt Rosen is at the wheel of a rental truck, on I-95 on a mission to University of New Hampshire. At right, Leo Tsai, John Ng and Mason Klein are figuring out how to get a 3He polarizer out of the truck.

 

The prototype open-access very-low field human MRI system was built at University of New Hampshire. Although this collaboration has now ended, the construction of the prototype system and initial images acquired were a guiding process in the design and construction of the optimized second generation system now being built at the CfA. Leo demonstrated the vertical oreintation imaging position with the RF coils in place near his chest (left), while at right Leo and John are accurately adjusting the placement of a phantom sample in the imager.

 

Ross was usually found sitting at the host computer of the console (left), with the highly modified commercial gradient power amplifier and RF monitoring rack behind him. (The second generation system will be much more compact, featuring a commercial RF control console designed to work at 100 - 300 kHz, and a modern Windows-XP interface on the host!). Despite the hardware, we generated some impressive results, which usually bought a crowd gathering around the offline image-processing computer (right).

 

Matt and Leo had built the 3He polarizer for this project, and Matt was often seen tending his "baby". This polarizer has since been relocated to BWH for a collaborative project involving high-field human MRI. The one drawback of 3He polarization by spin-exchange is the long pump-up time, which did give us the chance to make regular trips to the UNH Diary Bar, for the best ice-cream north of Boston.

 

The 3He inhalation project is just getting underway at BWH in December 2003. In this location, we get to work in the salubrious hospital environment, although in more cramped space. These photos are taken at the 1.5 T human scanner located down the corridor from our collaborators' lab-sapce in a building adjoining BWH. At left, Matt shows he can also drive the General Electric Medical Systems human scanner console, while at right, Matt, Sam Patz (our BWH host) and Tina Pavlin debate the value of the3He gyromagnetic ratio,

 

Our collaborators at BWH are Sam Patz, and his colleague, independent contractor Mirko Hrovat, an electronics expert who's company is providing most of the RF coil design experience for this project. Ross managed to squeeze into their electronics workshop space with them at BWH when they were working on a coil designs.

Meanwhile, back at the CFA, the dual-noble-gas maser team are hard at work in the small climate-controlled lab that houses the dual-noble-gas maser. Ron (left), David Phillips and Matt (right) are advising Federico Cane (front) about the use of the two-species129Xe/3He Zeeman maser for tests of Lorentz symmetry (both rotations and boosts) for the neutron. Actually, they look like they're posing for the camera, but you get the idea!

More hard-at-work photos from the rest of the group will appear once we get around all the optics and maser labs with the camera