JET_46123_com.dat  ITER Profile Database;  datasets prepared 
   by Pam Stubberfield,  July 1999
   
   Pulse #46123 is one of the best Optimised Shear JET discharges with
   reduced current Ip=2.5MA and reduced toroidal magnetic field Bt=2.45T.
   Its characteristic feature was the utilisation of Argon bleed which
   allowed a reduction of the heat flux through the separatrix and the
   avoidance of violent type I Elms at the transition to the ELMy H-mode
   In all other respects this discharge was similar to other optimised
   shear plasmas on JET. It was initiated with a fast current ramp so
   that the current reached its maximum value at 45.0sec. 1 MW of ICRH
   power was used for preheating beginning from t=42.5 sec. The main
   heating was applied at t=43.9 sec and reached its full capacity
   (13.5 MW of NBI and 4 MW of ICRH) at t=44.0 sec. Plasma energy reached
   its quasi steady state level of 7MJ at t=45 sec with the confinement
   enhancement factor H89 up to 2.5. This high performance phase lasted
   for about 2 sec. At that time NBI power was reduced to 5 MW which led
   to a termination of the internal transport barrier.  The radiated power
   started to rise after the beginning of Ar bleeding and saturated at the
   level of about 5 MW. The discharge was affected by a tearing-like mode,
   which started at about 45.6s and lasted until the very end of the high
   performance phase.  


   The dataset files in this subdirectory were prepared from TRANSP run
   204O run by Yuriy Baranov on 12 Feb 1999 on the ROSS batch workstations
   based on JET shot 46123 taken on  6 November 1998.
   There are 23 1-D Ufiles and 37 2-D Ufiles.  All beam related quantities
   (energy, particle sources, currents etc) have been smoothed to
   suppress Monte-Carlo noise. In the 2d file the deuterium density is
   stored in NM1. 
   In the file JET_46123_0d.dat data is given at 46.60 secs during the
   ELMy H-mode phase the ICRH power being at 2.8 MW and the NBI at 13.4 MW. 

   Values for kappa and delta in the 0d, 1d and 2d files are from the TRANSP
   output derived from the boundary input definition provided by EFIT.
        kappa = (Zmax-Zmin)/(Rmax-Rmin);   delta = (RGEO - R(Zmax))/a
   XPLIM is from XLOC ; SEPLIM is given by EFIT.
   PLTH is defined by WTH/TAUTH coming directly from TRANSP output and not 
   as defined in the standard list of variables. The 1d files for IP,VSURF 
   and IBOOT have negative values as normal for JET. 
  
   Some comments on this particular TRANSP run 204O;
   50ms analysis time resolution; VMEC equilibrium LEVGEO = 6 up-down asymmetry 
   Ti profile from CX measurements is used from 43.75 to 47.2 secs, before
   and after this time period a Ti profile is provided by assuming Xi=2*Xneo.
   Te profile vs. radius is from ECE measurements mapped by TRANSP equilibrium.
   Ne profile from LIDAR measurements;1D bulk radiation is used in the analysis.
   Rotation velocity profile from CX measurements is provided.
   1D Zeff from visible bremsstrahlung to 43.10 secs then 2D Zeff profile
   profile was invented for 43.15<t<47.15 secs (no data available) then
   1D Zeff again; C impurity. Edge ptcl confinement time is set to 1s.
   q profile provided by EFIT used from start of run at 42.0 secs
   until 43.5 secs. TRANSP field diffusion then provides the q profile.
 
   The TRANSP run 204O gives a simulated W_dia and neutron yield about
   20% lower than the measured values. This may be due to the uncertainty
   of the Ti and Zeff measurements from CX caused by the presence of Ar.