Construction of the Compact Toroidal Hybrid -

-The Compact Toroidal Hybrid (CTH) is currently under construction at Auburn University. CTH is a stellarator/tokamak hybrid device that will use an ohmic current of I_p<=50 kA to investigate both ideal and resistive current-driven instabilities in low aspect ratio stellarators. The edge vacuum rotational transform in CTH is variable from t_V(a) = 0.2 to 0.5, and the current-generated transform t_J(a)<=0.5. The average plasma major radius is R_o = .75m, the vacuum vessel minor radius is a_v =0.29 m and the maximum average plasma minor radius is a_p =0.20m, decreasing as the vacuum rotational transform is increased. CTH is a low β (<= 0.5 ) machine and will operate at magnetic fields B_o<=0.5T. Target plasmas for ohmic current stability studies in CTH will be generated by ICRF at ω=ω_ci using a Nagoya Type-III antenna. RF power of P_RF<= 200kW at a frequency of 10 MHz is expected to produce plasmas with densities on the order of 1 x 10^19m^-3. The CTH vacuum vessel was expected in July and at that time the main poloidal field coils were being wound. Winding of the helical field coil will begin after the helical field coil molds arrive in November 2002. CTH coil feed designs minimize magnetic field errors. The CTH device is scheduled to be completed and operational in late 2003. Supported by US DoE Grant DE-FG02-00ER54610