29 June 1995 Greetings, There is a significant bug which I introduced into the FPP/SPRUCE program around 19-Oct-1993. This bug exists only in the standalone version of FPP/SPRUCE, and never made it into the version which is used in TRANSP. If you are using the ICRF wave deposition code SPRUCE which is part of FPP, you will want to fix it. To fix the bug, in the subroutine coefts.for, replace the line: dwnwrk = gcoef(i)**2/rmaj(i)**2 with c dwnwrk = gcoef(i)**2/rmaj(i)**2 c GWH FIX THE BUG I INTRODUCED ON 19-OCT-1993!: dwnwrk = gcoef(i)**2/rmaj(i)**4 In one test case I've looked at, this bug fix causes the power profile to be a bit broader, and makes the contour plot of the H_z RF field look more reasonable (more spread out and less concentrated in the center). ********************************************************************* I am working on incorporating a new version of SPRUCE developed by Michel Evrard, Jef Ongena, and D. Van Eester of the Laboratoire de Physique des plasmas in Belgium (see "Improved dielectric tensor in the ICRF module of TRANSP", in the proceedings of the Palm Springs RF conference, 1995). One of its main improvements is that it's dielectric tensor employs the full Bessel functions. This avoids the small kperp*rho expansions of the previous method, which broke down for energetic alpha particles and for the energetic minority tail. [The energetic species is still treated as a hot Maxwellian. Separate values of Tperp and Tpar are allowed, though we've forced isotropy for now, as they would like to do some more testing.] An order-reduction method is still used, and a nonlinear root finder is used to find the fast-wave root. Let me know if you would like a copy of the new standalone version of FPP with this new RF package... Greg