Current lens wheel configuration

When Joe was here on 4/30/12, we installed and adjusted the lenses in the lens wheel. For future reference, here's some measurements and a record of the current configuration of the lens wheel.

distances:
detector to O-box wall (CD013):   10.9 mm
detector to O-box wall (proposed for CD014) :  7.7 mm
O-box wall to lens front of wheel: 14.4 mm 
focal length of 1" KRS5 lens:  38 mm (measured at optical)
0.63um focal length of 1.5" KRS5 lens: 38 mm
0.63um focal length of 1.5" ZnSe lens: 38 mm

To calculate how deep to place the lenses in the lens barrels we calculated d_i from the lens equation:
d_i= (1/f - 1/d_o),  where we used 1000mm for the value of d_o.

For the 38mm focal lengths, this was d_i=39.5 mm

n(0.63um) =2.57
n(11um)=2.37

f_mir= 38mm * (2.37/2.57) = 35 mm

d_i=36.27 mm


For the ZnSe lens, we chose the closest possible distance to the detector,  ~ 25.3 mm in order to see the effect of an extreme case on the focus.

For the 1" KRS5, we chose the best 0.63 um focus distance for the current config (with the D-box standoffs the same as CD013),   total distance is 10.9+14.4+7.9mm = 39.5 mm

Before the next cool down (CD014) we will move the lens 3.3 mm away from the detector, to compensate for the 1/8" inward change of position of the detector.