1. The problem statement, all variables and given/known data An idealized theta-pinch geometry is an infinitely long, cylindrically symmetric (d-by-d theta = 0), translationally-invariant (d-by-d z = 0) plasma column with an externally applied axial magnetic field B_z_ext. This induced a large diamagnetic azimuthal current which produces its own magnetic field which opposes the external magnetic field. Assume the plasma column is in MHD equilibrium with velocity v = 0 and with mag field B_z(r) and gas pressure p(r). I'm stuck on the first part of the question which is find the differential relationwhich the field B_z and the gas pressure must satisfy. 2. Relevant equations gradp = j cross B maxwell's equations to replace the current with the curl of B 3. The attempt at a solution grad p = (del cross B_z z-hat) cross B_z z-hat del cros B_x z-hat = - d-bydr B_z theta-hat grad p = d-by-dr p (1/mu_0)(- d-by-dr B_z)theta-hat cross B_z z-hat = (1/mu_0)(- d-by-dr B_z) = d-by-dr p Is that the correct answer? Do I need to go further? Next I need to integrate to find an expression for the externally applied mag field as a function of B_z and p and I just don't see how i can integrate the expression i found above.