Overview of High Pulsed Power domain and their applications Dominique Huet - EGO I will talk about a subject you have probably never heard before and you will probably never hear after. It is a kind of break so you can have some rest. This subject is the high pulsed power, namely HPP, domain in which I was involved before arriving here 2 months ago. Mainly it deals with electrical energy and the generation of very powerful electrical pulses

Principles and applications of HPP Initial Storage ~min Marx generator Inductive Voltage Adder Water lines Éclateurs Capacitive storage Vacuum lines Plasma Opening Switch Inductive storage Pulse forming section ~µs Load ~100ns Z-pinch Short circuit Diode Electron Beam High Pressures Radiation High temperatures I describe now the way such type of machines works. First the energy is stored in capacitors with typical voltage between 50kV and 100kV. The charging time is of the order of the minute and the energy stored in a capacitor is around tens of kJ. Then, by the use of appropriate switches this energy is delivered to pulse forming section in a characteristic time of the order of the μs. And then this energy is delivered to load in around 100ns. Actually it is the load that fixes the characteristic rise time of 100ns. The experience has showed that the load works better with a short energy pulse than with a longer one. The generators are mainly of two types : the Marx generator and the IVA. Depending on the form the energy is transferred we have two types of machines : If it is mainly under the form of voltage pulse we speak about capacitive storages and the most common elements used are water line and high voltage switches. if it is mainly under the form of a current pulse we speak about inductive storage and the most common elements used are vacuum line and plasma opening switches. The loads can be of three types : - An open circuit or diode. In this case you generate an electron beam that impinges a target and produces breamstralhung in the range 100keV till 1Mev. It is used to study materials under such radiation or to radiography very dense object. A short circuit and then you obtain very high pressure in the Mbar range. It is useful for the Equation of State studies. A z-pinch and in this case you can have radiation in the soft X-ray range (500eV-10keV) that you can use directly or to heat a cavity (holeraum)

Generators and Z-pinch 2MA, 800ns 505kJ à 80kV Ø=5m, h=7m 4MA, 1µs 1120kJ à 50kV Ø=18m, h=3m Ø wires: 10 to 50µm Rpinch: cm hpinch: cm

Diffusion equation in the framework of the MHD The POS Cathode Anode CONDUCTION PHASE Plasma Plasma Guns OPENING PHASE Load Amplifier Generator Diffusion equation in the framework of the MHD The diffusion term installs a precursor field from which the 2 others effects can exist Problem when it happens on lengths smaller than those defining the validity of the MHD