Development and experimental study of oil-free capacitor module for plasma focus device

Area of Science:

• Pulsed power technology
• Plasma physics
• Capacitor engineering

Background:

• Traditional pulse capacitors face limitations in high-current applications (>10 kA) due to reliability issues like vaporization and end connection problems.
• Metalized dielectric film capacitors and bipolar electrolytic capacitors exhibit drawbacks such as energy scaling difficulties and limited peak current delivery.
• Bi-axially oriented polypropylene (BOPP) film with extended aluminum foil offers moderate power but presents challenges with electrical weak points and edge gap margins.

Purpose of the Study:

• To design and develop compact, oil-free capacitors with non-standard geometry for high-current delivery in sub-microsecond timescales.
• To address the limitations of existing capacitor technologies for plasma focus devices.
• To implement a cost-effective and less complex solution using BOPP film and extended aluminum foil.

Main Methods:

• Development of novel hollow cylindrical, oil-free capacitors with specific parameters (4 μF, 10 kV, 20 nH).
• Laboratory-scale concept development and implementation.
• Experimental testing and performance evaluation on a test bed, including shot life assessment.

Main Results:

• Successful development and testing of a new capacitor design.
• Achieved a shot life of 1000 cycles at the rated energy density level.
• Demonstrated the viability of BOPP film-based oil-free capacitors for high-power applications.

Conclusions:

• The developed hollow cylindrical, oil-free capacitors provide a viable alternative for high-current pulse applications.
• Technological methods and engineering techniques are now established for manufacturing and testing these advanced BOPP film capacitors.
• This advancement facilitates more reliable and scalable pulsed power systems for plasma focus devices.