The HIPER project  started in May 2004 and was funded by the UK Engineering and Physical Sciences Research Council (EPSRC) under the UK research councils’ Basic technology programme. The main objectives of the project was to construct a very  high power  pulse EPR spectrometers at W-band with extremely low deadtime and very high concentration sensitivity.  A secondary objective was to initiate the UK’s first  SDSL and PELDOR program.

The following pages discuss some of our approaches  in making  a high performance pulse EPR instrument at high frequencies at 1kW power levels.

The instrumentation involved making substantial technical advances in several key components many with state of the art performance including:

* new mm-wave isolators  (> 100dB isolation between source and cavity)

* new mm-wave feed horns  (-50dB side lobe levels – state of the art performance)

* very fast mm-wave pulses (80ps rise times at low power demonstrated)

* new quasi-optical frequency independent optical configuration reducing aberrations

* new high power fast switches – (switching times of 1 ns at 50kHz rep rates capable of handling 1kW pulse power)

* state of the art performance for induction mode isolation between source and detector (50dB typical and upto 100dB demonstrated at spot frequencies)

* high stability coherent detection

* 16 state phase control


The instrument offers:

* very high concentration sensitivity

* very low deadtime

* easy sample handling and cold sample loading