  SMES using high critical temperature superconductors are interesting for high
power pulsed sources. Operation at temperatures above 20 K makes cryogenics
easier, enhances stability and improves operation as pulsed power source. In
the context of a DGA (Delegation Generate pour l'Armement) project, we have
designed and constructed a 800 kJ SMES. The coil is wound with Nexans
conductors made of Bi-2212 PIT tapes soldered in parallel. The coil consists in
26 superposed simple pancakes wound and bonded on sliced copper plates coated
with epoxy. The rated current is 315 A for an energy of 814 kJ. The external
diameter of the coil is 814 mm and its height 222 mm. The cooling at 20 K is
only performed by conduction from cryocoolers to make cryogenics very friendly
and invisible for the SMES users. The cooling down has been successfully
carried out and the thermal system works as designed. After a brief description
of the SMES design and construction, some tests will be presented. From a
current of 244 A, the SMES delivered 425 kJ to a resistance with a maximum
power of 175 kW.
