The applicator comprises three sections. At the lower end, a launch section transfers the microwaves from the coaxial microwave source into a PTFE-filled waveguide. The simulations below show the field distribution in the proposed design in an oblique view (top) and a view into the broad wall of the waveguide.The coaxial lead enters on the left.

Transmission into Waveguide as a Function of antenna length

0.82

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Length of Antenna / mm

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Transmission into Waveguide as a function of earthing connector diameter

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0 0.5 1 1.5 2 2.5 3 3.5 4

Radius of rod / mm

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Simulations have allowed optimisation of the dimensions of the transition components. The plots illustrate the process of calculating the optimal values of the antenna length and diameter to maximise energy transfer into the waveguide (measured as S12)

1. Connector attaches to base plate 2. Centre rod attaches to connector

Typical panel mount N-type connector; the kind that will be used in the applicator.The primary axis antenna section will be directly connected using a tight fit to the copper core centre conductor. .

Suggested construction process

3. PFTE block sheathes the rod 4. Earth support screws into centre rod5. Assembly is inserted into the waveguide6. Earthing rod is bolted to waveguide wall

Power transfer within the channels, (above) showing the high energydensity at the lower end. Energy densities in NMP are calculated to be In excess of 10W/cm3 with an input power of100W. The plot to the left, shown with a logarithmic power scale, illustrates how energy density varies along the entire applicator.

At the top, the choke section comprises a simple metal block to retain microwaves within the cavity. The ribbon passes through two slots of appropriate size.

Calculation of the electric field strength at the top of the choke under the worst conditions, where an absence of solvent means that all the microwave energy reaches the top of the waveguide. Electric field strengths in the space 5cm above the choke is significantly less than 1V/m, this figure itself being less than 1% of the permitted exposure limits.