Application Note: Measuring the Magnetic Fields required to produce Cold Plasma

The Measurement of E-fields inside Plasma requires the measurements to be taken within a very strong electric field (kV/m to MV/m) and near the ionize a gas containing the charged particles.
The measure of this field must be physically very close (few millimeters or less for cold plasma to tens of centimeters for hot plasmas).

The transient evolution of the electric field associated to plasma is very complex.

Example of specific projects:
 In-situ plasma mappings with different environments such as biological or magnetic
 Absolute measurements of electromagnetic pulses (EMPs) generated by laser-plasma interaction in nanosecond regime
 Measurement of penetration depth of the plasma E-field inside biological liquids

Representation of the amplitude of an E-field measurement in time-domain

Existing technical E-field measurement
Up to now, plasma may be measured via the following methods:

• Measurement of the power supply voltage (very limited information obtained)

• Measurement of the electric field with a Langmuir probe (only the average values may be obtained from electronic density or from the plasma potential)

• In addition to these measurement solutions, simulations may be calculated but the accuracy of the results are very limited.

Proposed solution by Kapteos

The Kapteos esSense Converter and eoProbe solution is currently the only solution on the market that allows for a comprehensive measurement of the electric field of cold plasma in air or even within a liquid.

The Kapteos electro-optic solution presents the best possible measurement system thanks to:

• Non-invasive measurement (no metal part)

• Near vector E-field measurement (phase and amplitude)

• A transverse spatial resolution of < 0.5 mm

• Supports Ultra-wide band frequencies

• A very compact design (5 mm * 35 mm)

• A wide operating temperature (0 … +50 °C)

• The possibility to measure very high fields (up to several MV/m)

Customer advantages of using Kapteos solution
A detailed monitoring of the E-field, leading to a high quality and performances of the plasma.

Targeted markets
Any manufacturers of cold plasma in the following domains:
• Research
• Medical
• Agriculture
• Semiconductors

Kapteos references
• University of GREMI lab. at Orléans (FR)
• Institute of INP at Greifswald (DE)
• University of Minnesota (MN – USA)
• Laboratoire de Physique des Plasmas (FR)
• Old Dominion University (VA – USA)

 Application Note: Measuring the Magnetic Fields required to produce Cold Plasma