DNP for the US Magnet Lab

Thursday, 25 July 2013

Thomas Keating Ltd has won a 150 K USD order to provide the US National High Magnetic Field laboratory with a 395 GHz Quasi-Optic transmission line for a new Dynamic Nuclear Polarization instrument they are building.

Our job is to couple efficiently power from a gyrotron to the sample buried deep inside a high homogeneity superconducting magnet. The use of DNP to enhance NMR spectrometer sensitivity is generating great excitement in the structural biology community.

Our subsystem will use

· Sum-of focal lengths frequency-independent optics to transport the diverging Gaussian-beam output from the Gyrotron to the sample probe, over a distance of about 3M
· employ a beam tap-off with an electroformed corrugated horn to monitor the power of the beam.
· provide switched safety feature that dump the beam into a high-performance load.
· use 10u W wire-grid polarizer (WGP) based beam attenuation.
A Martin-Puplett Interferometer will use a combination of moveable and static mirrors with WGPs to create the circularly-polarized microwaves used for efficient DNP coupling
· The beam will finally be focused into a low-loss HE11 corrugated circular waveguide that will provide an efficient transfer of microwaves inside the superconducting magnet’s bore.

July 2013