Radial and Vertical Build
Simplified scale diagrams of the vertical and horizontal cross-sections of the machine can be
output in the 2-page summary using the utility plot_proc.py (currently stored in process/process/io).
The coordinate system is (R,Z) system, where R is the radial distance from the vertical centreline (axis) of the torus, and Z is the vertical distance from the equatorial midplane.
Components are often referred to as being 'inboard' or 'outboard', which simply
means that they lie at a radius R less than or greater than R_0,
respectively, where R_0 is the plasma major radius (rmajor).
The radial build is described in detail in the OUT.DAT file as in the example below, which lists the major radius of each component in the midplane. The machine is axisymmetric, except for the TF coils which are discrete. The variables marked "IP" below are input variables. Those marked "ITV" are available as iteration variables (although it is not always advisable to use them as iteration variables). Those marked with an asterisk (*) may or may not be input variables depending on the switches used.
************************************************ Radial Build ***************************************
Device centreline 0.000 0.000
Machine bore 2.124 2.124 (bore) IP, ITV
Central solenoid 0.500 2.624 (ohcth) IP, ITV
CS precompression 0.065 2.689 (precomp)
Gap 0.050 2.739 (gapoh) IP, ITV
TF coil inboard leg 1.400 4.139 (tfcth) IP
Gap 0.050 4.189 (tftsgap) IP
Thermal shield, inboard 0.050 4.239 (thshield_ib) IP
Gap 0.020 4.259 (gapds) IP
Vacuum vessel (and shielding) 0.600 4.859 (d_vv_in + shldith) IP
Gap 0.020 4.879 (vvblgap) IP
Inboard blanket 0.755 5.634 (blnkith) IP*
Inboard first wall 0.018 5.652 (fwith)
Inboard scrape-off 0.225 5.877 (scrapli) IP, ITV
Plasma geometric centre 3.265 9.142 (rminor)
Plasma outboard edge 3.265 12.408 (rminor)
Outboard scrape-off 0.225 12.633 (scraplo) IP, ITV
Outboard first wall 0.018 12.651 (fwoth)
Outboard blanket 0.982 13.633 (blnkoth) IP*
Gap 0.020 13.653 (vvblgap) IP
Vacuum vessel (and shielding) 1.100 14.753 (d_vv_out+shldoth) IP
Gap 1.900 16.652 (gapsto)
Thermal shield, outboard 0.050 16.702 (thshield_ob) IP
Gap 0.050 16.752 (tftsgap) IP
TF coil outboard leg 1.400 18.152 (tfthko)
The radial build is shown schematically below (click to zoom).
The vertical build is described in detail in the OUT.DAT as in the following example, which lists the vertical coordinate of each component at the point furthest from the midplane (excluding the CS, the other PF coils and the cryostat). The midplane is defined to be half way between the top and bottom of the plasma. A single-null scenario is assumed to have a lower divertor, in which case the machine is not symmetric about the midplane.
*********************************************** Vertical Build *************************
Single null case
Thickness (m) Height (m)
TF coil 1.576 9.862 (tfcth)
Gap 0.050 8.286 (tftsgap)
Thermal shield 0.050 8.236 (thshield)
Gap 0.050 8.186 (vgap_vv_thermalshield)
Vacuum vessel (and shielding) 0.600 8.136 (d_vv_top+shldtth)
Gap 0.020 7.536 (vvblgap)
Top blanket 0.869 7.516 (blnktth)
Top first wall 0.018 6.647 (fwtth)
Top scrape-off 0.600 6.629 (vgaptop)
Plasma top 6.029 6.029 (rminor*kappa)
Midplane 0.000 -0.000
Plasma bottom 6.029 -6.029 (rminor*kappa)
Lower scrape-off 2.002 -8.031 (vgap)
Divertor structure 0.621 -8.652 (divfix)
Vacuum vessel (and shielding) 1.000 -9.652 (d_vv_bot+shldlth)
Gap 0.050 -9.702 (vgap_vv_thermalshield)
Thermal shield 0.050 -9.752 (thshield)
Gap 0.050 -9.802 (tftsgap)
TF coil 1.576 -11.379 (tfcth)
The vertical build is shown schematically below (click to zoom).
Since PROCESS is essentially a 0-D code, the shape of each component is used to estimate its mass
and cost, but is not used otherwise. The first wall, blanket, shield and vacuum vessel may be
either D-shaped in cross-section, or each may be defined by two half-ellipses. The choice between
these two possibilities is set using input parameter fwbsshape, which should be
- 1 for D-shaped,
- 2 for ellipses.
TF coil placement
The radial build can vary from the figures above dependant on the placement of the inboard TF
coil leg when using the tf_in_cs switch. See TF coil page**