Virginia Diodes Inc very kindly hosted Richard Wylde and Jonas Kindervater of Johns Hopkins for initial trials of a novel Electron Spin Resonance Bridge... which will feature VDI high power Sources at 108 and 216 GHz. The Bridge forms part of a complex neutron diffraction experiment devised by Prof Collin Broholm of JHU which will be run at the NIST Gaitherburg reactor facility to look at novel quantum materials (topological materials, quantum spin fluids ).
The bridge routes power from VDI's sources to a long HE11 corrugated probe which drops down inside a magnet to the sample help at sub 1K levels. A Martin-Pupplet polarizing interferometer allow both linear injection (to give Inductive mode ESR operation) .....as well as circular polarization... to maximise the hyperpolarization of the sample's electronic system.
Cliff Rowland of VDI and Jonas are freatured here - with the Bridge and vertically set VDI tranceiver heads on the right.
and a snapshot of the VNA show total Insertion loss from horn waveguide to waveguide - though a Faraday isolator and some 30 optical components of just over 3.3dB. Isolation of the source from back reflections is at the 36dB level.... results we are very happy with.
For more details, read a pdf of an upcoming poster at the CANCUN IRMMW conference in the Autumn