SSX Device Description

The spheromak is well suited as a stable resevoir of magnetic flux for reconnection studies.

We make our spheromaks in the following way:

SSX parameters are similar to solar flare parameters:
Swarthmore Spheromak Experiment Parameters (SSX)
Parameter SSX experiment Solar flare
proton density 1013 to 1015 cm-3 1011 to 1013 cm3
temperature 20-50 eV 10-100 eV
characteristic magnetic field 0.01 to 0.1 T 0.01 to 0.1 T
b=Ethermal/Emagnetic 0.1 0.01 to 0.1
Alfven velocity 105 m/s 106 m/s
characteristic scale 0.1 m 106 to 108 m
magnetic Reynolds number 100-1000 109 to 1014
magnetofluid volume 100 liters 1020 m3
particle inventory 1019 protons 1032 protons
stored energy 25 kJ at 10 kV (x4) Up to 1025 J
duration (tsustain) 100 µs 1000 s to several days
duration in units of Alfven transit times of the characteristic scale 100 103 to 105
flux conserver soak time (tflux conserver) 5 to 15 ms
stuffing flux Fgun 4 mWb
gun current Igun 100 kA

Distinctive SSX Features

SSX Design

Visible here are the capacitor banks to the right and the vacuum chamber to the left. The green stuffing flux magnet is mounted on the endcap of the vacuum chamber. The coaxial plasma gun is located in the endcap and is powered by the black cables.

The first experiment formed small speromaks into a flux conserver the size of the gun.

Large spheromaks are injected into a larger flux conserver.

To study reconnection, two large spheromaks are formed from opposite ends of the vacuum chamber. Symmetrical holes in the adjoining flux conserver walls allows the spheromaks to communicate.


Go on to Formation and Equilibrium Studies

July 21, 1997 /