So what is this ol' farmboy doing on the lawn of Killian Court at MIT (Masachussetts Institute of Technology) in Cambridge, MA ?
Photo: September 10, 2009
We note that the landmark Great Dome is under repair and hence is surrounded by scaffolding.
Very recently I have been involved with a local business group that may
introduce a
NMR (nuclear magnetic resonance) spectrometer
based upon a superconducting magnet.
This scientific instrumentation is used in schools, universities and industrial research laboratories to study the structure of
all manner of chemical compounds.
In terms of it's basic functionality it would be very similar to an instrument pioneered by Bruker Physik AG in Karlsruhe, Germany, back in the 1970s:
Photo: Bruker HX270 spectrometer brochure (1972)
I was in the Karlsruhe facility at the invitation of Herr Prof. Günther Laukien, the charismatic Bruker founder.
This particular NMR spectrometer observed the hydrogen atoms that form a very large percentage of all organic matter
on our earth - including the human body - at a frequency of 270MHz. The observation depended upon inserting a small tube of a chemical compound, containing hydrogen, into a high-intensity magnetic field (63kG)
as produced by a superconducting solenoid-magnet.
The prototype Bruker magnets were designed and fabricated by a team of scientists, engineers and technicians that I headed up in Burlington, MA:
The complete magnet assembly is to the right in the photo of the HX270 (see above), along with its liquid helium refrigerator.
The magnet design was initiated by Joel Pitlor, a graduate of MIT, at the Burlington facility while I was in Karlsruhe.
During the magnet's development I was in close contact with personnel at MIT's Francis Bitter Magnet Laboratory (FBML),
in particular Leo Neuringer who was interested in establishing a world-class NMR facility.
Prof. Francis Bitter was famous for his electromagnet designs that attained the highest ever field strengths,
for their time, by running very high electrical currents through copper plates. These plates, when stacked and water
cooled, formed a solenoid which in turn produced the magnetic field:
Photo: Massachusetts Insitute of Technology / Calvin Campbell
The FBML was required to design and assemble a special DC generator, with a flywheel weighing over 80 tons, to drive a Bitter magnet. It used megawatts of energy and the residents of Cambridge often experienced a brown-out when an experiment with a Bitter magnet was in progress!
However, with the advent of superconducting materials, and thence cold-drawn wire, solenoids could be wound on a bobbin and installed in a dewar holding very cold liquid helium. At this temperature, close to absolute zero, large
currents could flow in the superconducting solenoids without dissipating heat. Thus the water-cooled Bitter magnets were superceded for all but some very specialized physics experiments. In fact the
FBML has just dismantled the
old generators to make room for the latest NMR spectrometer. It will be using a supercon magnet with a field strength about 4 times higher than for the Bruker HX270 spectrometer. It will also stand 2 stories tall.
So I was back at MIT visiting with colleagues from the "Bruker days", including John Waugh who
is still active as Emeritus Professor of Chemistry. John is a wonderful fellow, who acted as a consultant to Bruker
for a number of years. I worked very closely with one of his students, David Ellett, who was also invited to join the NMR team at Bruker. Another of John's students at the same time was Robert Griffin, who is now the Director of the FBML. He is also the recipient of the 2003 Günther Laukien prize - awarded for outstanding achievements in the international field of NMR.
To conclude this topic, for the moment, here is a photo of
Prof. Günther Laukien that I still
have from the time spent in Karlsruhe:
PS. My first daughter, Karen, was born in Ettligen - just outside of Karlsruhe, Germany.