Article

Fundamental investigation in two flashover-based trigger methods for low-pressure gas discharge switches

Phys. Dept., Univ. of Erlangen-Nurnberg, Erlangen, Germany
IEEE Transactions on Plasma Science (Impact Factor: 0.95). 03/2004; DOI: 10.1109/TPS.2004.825523
Source: IEEE Xplore

ABSTRACT Modern switches for pulse-power technology have special requirements such as long lifetime, reliability in a wide pressure and voltage range, as well as small delay time. In order to meet these requirements, two trigger methods were developed and examined. These two different trigger methods based on a flashover were tested for the emission behavior by variation of different parameters. The first configuration is a semiconductor surface flashover trigger, where electron emission is based on a surface flashover between the contact area of a copper spring and a carbide cylinder. The second trigger concept is the high-dielectric trigger, where electrons are released by the field emission effect at the transition between metal-vacuum and dielectric. For this system, high dielectric materials with dielectric constants in the order of 2000 are available. The electrical and optical measurements of both trigger systems were done in a modular structured vacuum chamber. For lower pressure, the high-dielectric trigger shows better performances and higher emitted charge of the electron emission within all adjusted parameters like gas pressure, applied voltage, and different wirings. In addition to the higher emitted charge, the emitted electrons from the high-dielectric material have higher energies. For the lifetime characteristic, the high-dielectric trigger shows lifetimes much higher than 100 million discharges.

0 Followers
 · 
73 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: form only given. For handling high currents and voltages reliable and durable switching devices are needed. When it comes to maximum power applications the use of gas-discharge-switches is still inevitable.
    Plasma Science (ICOPS), 2012 Abstracts IEEE International Conference on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: A triggered surge protective device is designed and its discharge characteristics are studied. The experimental results show that the triggered surge protective device has excellent surge protective characteristics. When the gap distance is 5 mm, p · d is 90 Pa·mm and without an active energy trigger circuit, the DC breakdown voltage of the triggered surge protective device is 2.32 kV and the pulse breakdown voltage is 5.75 kV. Therefore, the pulse voltage ratio, which is defined as the specific value of pulse breakdown voltage and DC breakdown voltage, is 2.48. With a semiconductor ZnO flashover trigger device and an active energy coupling trigger circuit, the pulse breakdown voltage can be reduced to 3.32 kV, the pulse voltage ratio is 1.43 and the response time is less than 100 ns. These results are helpful in laying a theoretical foundation for further studies on triggered surge protective devices.
    Plasma Science and Technology 08/2012; 14(8):759-764. DOI:10.1088/1009-0630/14/8/14 · 0.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The planed Facility for Antiproton and Ion Research (FAIR) is a new international accelerator laboratory at the GSI in Darmstadt, Germany. One research topic at this facility is aimed to protons and anti protons colliding experiments. After generation of these antiprotons strong magnetic fields are necessary to focus the antiprotons. To achieve this high magnetic fields a magnetic horn will be used. To generate for this application the necessary high magnetic field the designed stripline of the pulse forming network (PFN) has to handle a peak current of 400kA with a pulse length of 20μs. Currently the only possibility to handle this high current is the use of mercury filled Ignitrons. The plasma physics working group at the University of Frankfurt develops a mercury free switch, which is able to replace the Ignitrons in the PFN of the magnetic horn. This contribution shall give an overview about the development of a gas discharge switch with minimized local electrode erosion. The experimental setup of the switch consists of coaxial electrodes, similar to the geometry used for plasma focus devices. The main discharge between the coaxial electrode system will be initiated by a trigger predischarge. After the ignition of the main discharge between the coaxial electrode system and due to the interaction of the induced radial magnetic field with the plasma, the gas discharge will be accelerated to the open end of the coaxial electrode system1. This acceleration of the plasma sheet is due to the Lorentz force, which interacts with the discharge. Therefore the switch will be called a Lorentz Drift Switch (LDS). For the special application of the magnetic horn to provide enough charged particles several of these coaxial devices will be stacked together in a parallel.
    Plasma Science (ICOPS), 2013 Abstracts IEEE International Conference on; 01/2013