WIYN / Bench Rebuild:
Off-Axis Collimator Design

 

v1.0

This page contains technical notes for the process to design the OAC for the re-built WIYN Bench Spectrograph.
Design Requirements Summary 2003 PDR-level designs Other/intermediate designs 11 Aug 2005 design Final designs Tolerances

Requirements

Summary

2003 PDR-level Designs: Existing and OAC

These models establish the baseline for the current system, and initial 3-element designs with no control over pupil location and a 12-degree off-axis parabolic collimator.

Other Designs

These models explore 2-element aspheric reflection designs, and off-axis angles up to 16 degrees.

11 Aug 2005 OAC Designs

These models explore various pupil and grating distances with the "final" 4-element corrector design with a 14 degree off-axis parabolic collimator. They led to the final design configuration for pupil and grating back distances. All models use off-order H&alpha setup (order 9 / 8.5) with &alpha close to 77 deg. While this leads to significant grating vignetting, optimum grating-camera distance here is not presentative of on-order cases. The attached report summarizes the analysis of the Project Scientist.

Definition of terms:

&thetacc = camera-collimator angle (deg)
dcg = collimator-grating distance (mm), taken to be surface 32
dc33 = collimator-surface-33 distance (mm): surface-33 is near the pupil but not at it.
dcp = collimator-pupil distance (mm)
dcc = collimator-camera objective distance (mm)
dgc = grating-camera distance (mm)
dpc = pupil-camera distance (mm)

file name: *_folded_316ech9.zmx

Model
angles/lengths
LayoutPupil Location
PlaneSC_5X_Bias_f5_4el_14deg_NP_4a

&thetacc dcg dc33 dcp dcc dgc dpc
11 1003 1403 1403 1503 500 100

PlaneSC_5X_Bias_f5_4el_14deg_NP_4b

&thetacc dcg dc33 dcp dcc dgc dpc
11 803 1373 1422 1503 700 81

PlaneSC_5X_Bias_f5_4el_14deg_NP_4c_1

&thetacc dcg dc33 dcp dcc dgc dpc
11 803 1373 1373 1623 820 250

PlaneSC_5X_Bias_f5_4el_14deg_NP_4c

&thetacc dcg dc33 dcp dcc dgc dpc
11 803 1373 1373 1373 570 0

PlaneSC_5X_Bias_f5_4el_14deg_NP_4d

&thetacc dcg dc33 dcp dcc dgc dpc
12 803 1373 1373 1373 570 0

PlaneSC_5X_Bias_f5_4el_14deg_NP_4e

&thetacc dcg dc33 dcp dcc dgc dpc
13 803 1373 1373 1373 570 0

PlaneSC_5X_Bias_f5_4el_14deg_NP_7a

&thetacc dcg dc33 dcp dcc dgc dpc
11 1428 1728 1609 2244 816 635

PlaneSC_5X_Bias_f5_4el_14deg_NP_7

&thetacc dcg dc33 dcp dcc dgc dpc
11 1128 1628 1628 2144 1016 516


last updated: 19 Feb, 2006 (mab@astro.wisc.edu)