ZTF Detector/Filter Combinations P. Jelinsky

Optics Outline Look at different number of detectors –Can the sky be tiled? Do not consider gaps. Do not consider mapping unto a sphere –Can it use fixed filters efficiently –Does it have a viable stagable option? 2

7 detectors Cannot use fixed filters efficiently (since odd number of detectors) Can tile the sky efficiently No feasible stagable options. Maximum off axis angle: 3.2° 3 No Vignetting 10%Vignetting 20%Vignetting 30%Vignetting Tile Example

8 detectors Can use fixed filters efficiently Can tile the sky efficiently Has a feasible stagable option. –Start with 4 detectors along center line Maximum off axis angle: 3.6° 4 No Vignetting 10%Vignetting 20%Vignetting 30%Vignetting Fixed Filter Layout4 Filter Stage

8 detectors (cont) 5 Tile ExampleFixed Filter Tile Example (Shift 2 detectors horizontal) (then shift 2 detectors vertical)

9 detectors Cannot use fixed filters efficiently Can tile the sky efficiently No feasible stagable option. Maximum off axis angle: 3.8° 6 No Vignetting 10%Vignetting 20%Vignetting 30%Vignetting Tile Example

10 detectors Can use fixed filters efficiently Can tile the sky efficiently Has feasible stagable option. –6 detectors Maximum off axis angle: 3.8° 7 No Vignetting 10%Vignetting 20%Vignetting 30%Vignetting Fixed Filter Layout6 Detector Stage

10 detectors (cont) 8 Tile ExampleFilter Tile Example (Do tile pattern to left) (then shift 1 detectors horizontal)

12 detectors Can use fixed filters efficiently Can tile the sky efficiently Has feasible stagable option. –8 detectors Maximum off axis angle: 4.1° 9 No Vignetting 10%Vignetting 20%Vignetting 30%Vignetting Fixed Filter Layout8 Detector Stage

12 detectors (cont) 10 Tile ExampleFilter Tile Example (Shift 2 detectors horizontal) (then shift 3 detectors vertical)

Conclusion 12 detector option is the most flexible –Can come on line early with 8 detectors (if needed) –Can use fixed filters (if acceptable) –Can tile the sky efficiently The major issue is cost 11