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Welcome

Either on purpose or by accident, you have found what has become my research homepage. If you ended up here deliberately you are probably looking for information on my research (projects, publications etc.) or are searching on some more profound information on Pulsed Power in general. In both cases I hope you will find your curiosity satisfied. If you happen to be here by accident, I hope you will still spend a few more moments to let me intrigue you by a research area that harnesses "the power of the gods." More specifically the art of using very short high voltage pulses to do amazing things (generating lighnting is only one of them). The knowhow to provide these pulses is known as Pulsed Power science and technology.




What is Pulsed Power?

The name simply describes that short electrical pulses are associated with very high electrical power. For example a pulse with an amplitude of 100 kV (i.e. 100000 volts) and a duration of 100 ns (i.e. 0.0000001 seconds) delivered to a load of 10 ohms is putting out a power of 1 GW (1 gigawatt or 1000000000 watts). This power is equivalent to the output of a nuclear power plant, although for the mere 100 ns that it is available, the energy that is provided wouldn't even be sufficient to heat up your cup of coffee by even 1 degree (and it really doesn't matter if Celsius or Fahrenheit). As you can imagine these extreme conditions can not readily be realized on a typical printed circuit board. Furthermore, even material properties will be different when voltage of that magnitude are applied. Consequently, there is a devoted scientific community researching the area and many different aspects and applications of Pulsed Power Science and Technology. If I have sparked your interest, I encourage you to follow some of the links provided here.



What can you do with Pulsed Power?

  
Everbody's got an Opinion - Here's Mine:
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As an primarily enabling technology, Pulsed Power circuits are means to an end in many cutting edge applications. The use in pulsed high power laser systems, which are used for example in car manufacturing can already be considered a mainstream application - likewise the generation of shockwaves to disolve kidney stones (lithotripsy). As a unique way (and probably only way) to generate dense plasmas, Pulsed Power is also a key technology in the research on inertial confinement fusion reactors, such as the Z-Machine at Sandia National Laboratories or the National Ignition Facility operated by Lawrence Livermore National Laboratory. Beside these civilian applications, the technology is also used in many military programs, for example radars (probably the birthplace of pulsed power), high power microwave generators, and electromagnetic launchers ("railguns"). The variety of applications and research topics is given testimony by several hundred presentations each year at either the International Conference on Pulsed Power or the International Power Modulator Symposium.
     
   
 
Pulsed power in nature: voltage differences of 10-100 MV between heaven and earth lead to a "spark" which lasts for about 100 µs and carries currents on the order of 30 kA (return stroke). About 3.5 billion years ago, lightning in the early atmosphere generated the first building blocks of life (amino acids).
 
A growing interest in Pulsed Power technologies can also be found for medical and biological and environmental questions. Pulsed electrical discharges can be designed to create so-called 'streamers'. This non-thermal plasma has the ability to attack biological and chemical agents alike and is in particular promising for decontamination and purification of water (both fresh water and waste water). Another emerging application is the manipulation of mammalian cells with pulsed electric fields. 'Longer' pulses (in the microsecond range) are a widely successful tool to bring large molecules into cells as it is for example need in gene therapies. 'Shorter' pulses have demonstrated an ability to affect cells on a subcellular level. One of the most appealing results so far is that they can trigger apoptosis in cancer cells. By reminding cancer cells to undergo this 'programmed cell death', which these cells have forgotten, pulsed electric fields can be used to fight tumors. Both the use of discharge plasmas and pulsed electric fields on cells and tissues are cornerstones of a new era in biomedical engineering, summarized as Bioelectrics.



What is Bioelectrics?

   
 
Logo of the Frank Reidy Research Center for Bioelectrics. It shows the interaction of electromagnetic radiation and plasma ions with a cell.
 
Generally "Bioelectrics' describes the use of electrical stimuli or stimuli generated by electrical means on biological systems. These systems can be specific cells such as cancer cells, tobacco cells and bacteria, or more complex arrangements such as tissues or even very complex environmental systems, which include plants and animal species.Typical stimuli are plasmas (primarily non-thermal) but also electrial pulses, either unipolar or as electromagnetic radiation (e.g. microwaves). As broad as this definition is also the range of applications. The name 'Bioelectrics" was originally coined by Karl Schoenbach who first used it to describe the interaction of nanosecond pulsed electric fields with mammalian cells but soon expanded the scope to include plasma applications and the application of longer electrical pulses. In 2002 he became the director of newly founded Center for Bioelectrics, which focuses on the related research topics. The growing interest in the research was confirmed when several national (USA) and international institutions (including universities in Japan and Germany) came together in an International Consortium on Bioelectrics. The consortium, headed by the Center for Bioelectrics has grown ever since is to this date (January 2009) including 3 universities in the US, 3 institutes in Germany, 2 instiutes in France and 1 university in Japan. (More information can be found on the webpages of the Frank Reidy Research Center for Bioelectrics.)



Who am I?

My name is Juergen Kolb. I am an Assistant Professor with the Center for Bioelectrics at Old Dominion University. My faculty assignment lies within the Department of Electrical and Computer Engineering. As I have mentioned, I am hosting this webpage as my research homepage. You will therefore find mostly discussions and presentations on my own reasearch projects here. Unfortunately time constraints will probably force me to keep this page more 'static' than I would like it to be. As you might have figured out by now, my main research interest lies in medical and environmental applications of pulsed electric fields and non-thermal plasmas. Apart from that - and closely related - is a keen interest of mine in Pulsed Power Science and Technologies. For this reason I will also use this webpage as a forum for other Pulsed Power topics that interest me. Last but not least I will use this page as 'resource page' both for my class on pulsed power and to provide tools, links etc. of general interest. I hope you will find this page useful and enjoy it. For the future I'm planing to put up also a similar websites on Bioelectrics. That both websites are registered as European (.eu) and German (.de) domains simply lies in the fact that the US domains were already taken.


Juergen Kolb, January 2009 (updated November 2009)




mail to: webmaster@pulsedpower.de