Multi-wire X Pinches on the COBRA Pulsed Power GeneratorT.A. Shelkovenko, S.A. Pikuz,

J.D. Douglass, R.D. McBride, and D.A. Hammer

Laboratory of Plasma Studies, Cornell UniversityIthaca, NY 14853, USA

6th International Conference on Dense Z-pinches Oxford, 2005

Top view of COBRA chamber

X pinches with 1 MA current

X pinch timing

Shot#

Imax(kA)

Ixp(kA)

X pinch wires Radiated energy,first burst (mJ)Eγ > 1.7 keV

Radiated energy, allbursts (mJ)Eγ > 1.7 keV

185 520 420 6x40 µm Mo 250 ~ 1200

187 640 550 12x25 µm NiCr 150 ~ 500210 678 590 6x25 µm W 200 ~500212 700 650 6x40 µm Mo 300 ~750217 870 750 6x50 µm Invar 450 ~ 1000320 924 600 8x25 µm

manganin100 (Eγ >2.5 keV) ~500 (Eγ >2.5 keV)

326 1012 850 8x50 µm W > 1700 >1700330 ? ? 8x50 µm W ~ 1600 2500

Table 1. Estimated energy yield of central X pinch on COBRA.

South X pinch Eγ > 0.7 keV

North X pinch Eγ > 0.7 keV

Shot # Load current (kA)

Wires (µm) Energy(mJ) Wires (µm) Energy (mJ)200 820 4x12.7 Mo 15 4x17 Mo -204 926 4x12.7 Mo 10 4x17 Mo -207 1008 4x12.7 Mo 120 4x17 Mo 30208 981 4x12. Mo 55 4x12.7 Mo 20222 917 4x12.7 Mo 40 4x12.7 Mo 10

Table 2. Estimated energy yield of X pinches in a return currentcircuit of the diode on COBRA.

Conclusions

• COBRA pulsed power generator is a promising device for X pinch experiments.

• The experiments show the X pinches can have very high plasma and x-ray burst parameters if proper wire materials and masses were chosen.

• COBRA generator give the possibility of essentially extend of the X pinches plasma and radiation parameters and, because of that, field of application.

This research was supported in part by DOE grant DE-FG03-98ER54496, in part by Sandia national Laboratories Contract AO258, and in part by the

Stewardship Sciences Academic Alliances program of the National Nuclear Security Administration under DOE Cooperative agreement DE-FC03-

02NA00057