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The new 6 MJ generator of the Toulouse Pulsed High-field Installation

In order to generate pulsed magnetic fields one needs to inject considerable amounts of energy ( 5 MJ which is equivalent to 1.2 kg TNT explosive) into a coil. This energy is needed during a very short time ( 10 ms), so requiring in principle an electrical power of 500 MW (comparable to the capacity of one power plant). It is clear that a direct supply of our coils from the mains is not be feasible. The well-known solution to this problem is intermediate energy storage. One accumulates electrical energy drawn from the public mains during a relatively long time ( 200 s) in capacitors, and discharges this energy very rapidly (( 10 ms) into the magnet.

The LNCMI-T has already several generators ranging from 150 kJ up to 14 MJ and working at a maximum voltage of 24 kV. The 14 MJ generator can dump its energy in 23 ms providing a current of 65 kA. To make higher fields, higher currents are needed. The new 6 MJ generator can deliver its energy in 5 ms and generates a current of nearly 150 kA. The short discharge avoids heating of the coil, and the high current willallow us to go above the field of 100 T, the current world record, in the future.

Last, but not least, it was decided that this new 6 MJ generator should be transportable. This additional flexibility, will assure that the LNCMI keeps its leading position concerning the use of pulsed magnetic fields at other large research centres (synchrotrons, neutron sources and intense lasers).

Funding was obtained from the CNRS and the EU-FEDER. A public tender was launched and ITHPP, a company specialised in pulsed power was selected. Each module is built in a 20-foot sea container and weighs 15 ton (Fig. 1). In January 2014 two lorries which one module each and a big crane arrived to install the containers at their temporary position next to the LNCMI building (Fig. 2). They will have to be moved again in 18 months when our building extension has been finished. but in the meantime we made already fields above 80 T with a single coil using the new generator (Fig. 3).

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Fig. 1 the (blue) capacitors and the (brown) fuses installed inside the container befor cabling.
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Fig. 2 a generator module arriving on site.
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Fig. 3 The first 80 T magnetic field pulse produced with the new 6 MJ generator