In the realm of high-voltage pulsed power, the selection of core technology is critical. APELC’s specialization in Marx generators is not a matter of happenstance, but rather a result of rigorous analysis and decades of practical application. This blog post explores the fundamental reasons behind our focus, rooted in the foundational work of Dr. Jon Mayes and the unique capabilities of the compact, wave-erection Marx generator.
Historical Context and Technical Foundation
Dr. Jon Mayes’s graduate research, conducted in the late 1990s, necessitated a high-voltage pulse generator capable of achieving rapid over-voltage of a spark gap (approximately 100 kV/ns) while maintaining precise synchronization with a laser trigger. The requirements – high peak voltages (hundreds of kV), sub-nanosecond rise times, and sub-nanosecond jitter – presented a significant technical challenge. His advisor, Dr. William Nunnally, directed him towards the work of Dr. David Platts at Los Alamos National Laboratory (LANL), specifically the wave-erection Marx generator. This technology, developed for high-speed transient studies and large pulsed power system triggering, offered a solution.
The Wave-Erection Marx Generator: Design and Advantages
The wave-erection Marx generator, as developed at LANL, employs a compact circuit within a pressurized, coaxial metal housing. The use of a solid dielectric and close component spacing minimizes inductance, enabling rapid energy discharge. Dr. Mayes’s research further advanced this technology, achieving sub-nanosecond rise times and jitter, and demonstrated the ability to generate high-voltage pulses with significant frequency content in the microwave range. This inherent capability to produce fast pulses with high voltage not only provided a means of over-voltaging a spark gap, but also presented a means to generate high-voltage pulses with frequency content up into the microwave portion of the electromagnetic spectrum.
APELC’s Application and Development
Upon founding APELC in 1998, Dr. Mayes leveraged this expertise, securing SBIR grants to expand the application of these Marx generators. The rapid rise times (as low as 200 picoseconds) facilitated direct antenna coupling for high-power microwave (HPM) and ultra-wideband pulse generation, critical for electronic effects testing and radar. The ability to tailor source impedance to match coaxial cables and antenna loads further enhanced system performance. APELC’s publications, available on our website, detail the development of systems utilizing TEM horns, helical antennas, and wideband dipoles, achieving field strengths exceeding 100 kV/m.
As APELC grew as a company, the compact wave-erection Marx generator remained the most important tool in our kit. Over the years, investments in personnel and machining/fabrication capabilities matured the design of these Marxes as well as the systems they sourced. Today, APELC uses this same technology to source our compact wideband test systems, high-altitude EMP (EMP) test systems, and on their own as a fully turn-key trigger generator systems for larger pulsed power machines at DOE labs.
Continued Relevance and Future Applications
While semiconductor technologies have progressed to the point of achieving nanosecond rise-times in the tens of kilovolts, the spark gap-based Marx generator remains the optimal solution for generating extremely fast, high-voltage pulses in the hundreds of kilovolts range. APELC’s continued investment in manufacturing and engineering has refined the design and application of these generators. Today, our technology is integral to compact wideband test systems, high-altitude EMP (EMP) test systems, and on their own as a fully turn-key trigger generator systems for larger pulsed power machines at DOE labs. We acknowledge the contributions of Erwin Marx, David Platts, Jerald Buchenauer, Bill Nunnally, and Jon Mayes, whose work has established the foundation of APELC’s core technology and 25-year history.
APELC’s focus on Marx generators is driven by their unique capabilities in delivering high-voltage pulses with exceptional speed and precision. This technology remains essential for advanced pulsed power applications, and we are committed to its continued development and application.
