n-Point Flotation Cells
All plano back mirrors must be supported by an n-Point Flotation system, such that there is no warping of the optics. Since we model these optics in their respective mirror cell, we can determine how well the mirror is supported (see data below each contour plot). And not only has this been modeled, we have demonstrated (on dozens of sets of optics) that our 9-point cell is excellent support for the plano back 14.5RC and even the 16RC.
RCOS designed and has been using this 9-point cell as "standard" equipment on the 14.5RC mirrors for the last 6 years.
16RC 9-pt Cell using 500 nm light:
Visible P-V Error 8.95949e-06 (0.0179 wave)
Visible RMS Error 1.74918e-06 (0.0035 wave)
However, we went a step further and modeled the same mirror using our 18-point cell developed in late 2003 and found the mirror support to be even better (see contour plot below). This 18-point flotation cell works exceptionally well (see data below) with the plano back 16RC primary mirror.
We recommend the 18-point cell for the 16RC, 20RC, 24RC and 32RC plano back primary mirrors.
16RC 18-pt Cell using 500 nm light:
Visible P-V Error 3.52923e-06 (0.0071 wave)
Visible RMS Error 6.10699e-07 (0.0012 wave)
The picture below illustrates what the 18-point cell looks like (without optics) when mounted in the 16RC backplate.
Note: The 32RC 18-point cell also utilizes 12 astatic radial supports (see below).