Note: discussion of some of this hardware and different options is also here: https://confluence.lsstcorp.org/display/LTS/Readout+and+Timing+Options+for+CBP+Calibration
...
But doing a simple sum over the whole spot taken with the canon camera, the total flux from the spot is identical to far less than a percent (or even one part per thousand) . CBP_calibration_spot_flux.ipynb. This is extraordinarily weird to me because the glass should reflect 4% of the light.
For an estimate of spot size (very, very crude - based on the above notebook, but I apparently failed at focusing even just on the fiber so take this with a grain of salt): spot size = 40 pixels (by eye this is an overestimate) * 5.25 um = 210 um. With an 800 mm lens that corresponds to an angle of .21/800 = .26 mrads. If we're 3 or 4 meters away that's (say 4): ~1mm. Huh. That is definitely not what I observed as a spot size...
Things built in shop:
Version for photodiode holder: 9/27/2023 Photodiode_holder_design.pptx
9/27/2023 sent this to shop: pinhole_holder_2 v6.step
Items that have been built in the shop: Rail_Connector.step Tube_End.step Tube_End_Drawing.pdf Rail_connector_drawing v3.pdf CBP_Calibration_Tube_end_drawing v3.pdf
New tube end design
Updating the tube end design so that we can mount a breadboard on it. I also increased the size of the center hole to 3", since we will be putting more cables through it.
| View file | ||||
|---|---|---|---|---|
|
Parts for baffling and possibly a flip mirror? There are a bunch of possible options:
- If we just use a Hamamatsu NIST photodiode then we can use the current tube end and use an SM2 tube to anchor it there and an SM1 (with adapter) to mount the photodiode. This is easiest. We can also attach another 2" tube and add baffling.
- If we add in a flipper mount to image on a camera, we want right angle brackets to be able to mount the flipper and camera.
- If we want to use a Fabry Lens (which may not work due to issues with chromatic aberration), then we need a cage system to set up the alignment.
| Part | Details | Price and Quantity |
|---|---|---|
| Fabry Lens option | Chuck proposes 18.7 mm lens for an 8 mm spot, but could go shorter if we choose spheres | Already ordered |
| Lens holder | 1/2" or 1" from Thorlabs, depending on desired lens | Have a number of them |
| Fabry Lens option | ACL1210U - Aspheric Condenser Lens, Ø12 mm, f=10.5 mm, NA=0.54, Uncoated https://www.thorlabs.com/thorproduct.cfm?partnumber=ACL1210U | 1 at $21.02 |
| Fabry Lens option | ACL25416U - Aspheric Condenser Lens, Ø1", f=16 mm, NA=0.79, Uncoated https://www.thorlabs.com/thorproduct.cfm?partnumber=ACL25416U | 1 at $20.56 |
| Baffling | SM2D25D - SM2 Ring-Actuated Iris Diaphragm (Ø1.4 - Ø25.0 mm) https://www.thorlabs.com/thorproduct.cfm?partnumber=SM2D25D#ad-image-0 | 2 at $98.31 |
| Adapters | SM1A2 - Adapter with External SM1 Threads and Internal SM2 Threads | quantity 2, $28.40 |
| adjustable SM2 tube. | quantity 1, $60.59 | |
| SM2 tube | SM2L03: SM2 Lens Tube, 0.3" Thread Depth, One Retaining Ring Included | quantity 3, $25.77 |
| SM2 tube | SM2L05: SM2 Lens Tube, 0.5" Thread Depth, One Retaining Ring Included | quantity 3, $28.42 |
| right angle brackets | AP90RL - Large Right-Angle Bracket, 1/4"-20 Holes https://www.thorlabs.com/thorproduct.cfm?partnumber=AP90RL#ad-image-0 | quantity 2, $194.83 |
| flip mount | MFF102 - Motorized Filter Flip Mount with Ø2" Optic Holder, 8-32 Tap | quantity 1, $773.33 |
| zoom housing for Fabry Lens system | SM1NR1 - SM1 Zoom Housing for Ø1" Optics, Non-Rotating, 2" (50.8 mm) Travel | quantity 1, $236.40 |
| precision zoom housing | SM1ZM - SM1 Zoom Housing for Ø1" Optics, Non-Rotating, 3.5 mm Travel | quantity 1, 193.64 |
| SM1 zoom housing | SM1NR05 - SM1 Zoom Housing for Ø1/2" Optics | quantity 1, $218.56 |
| SM1 adjustable threading | SM1V05 - Ø1" Adjustable Lens Tube, 0.31" Travel Range | quantity 1, $32.72 |