Winlight Inspection Reports

Entire Camera - Green

Description	Date	File
Final Inspection - Green	Sept. 28, 2021	WS-PVC3963-A.pdf

Camera Coatings - Green

Description	Date	File
Coating Inspection	May 25, 2021	WS-PVR1155-A.pdf

Individual Lenses - Green

Description	Date	File
Green L1 (Asphere)	Sept. 28, 2021	WS-PVC3747-A.pdf
Green L2	Sept. 28, 2021	WS-PVC3766-A.pdf
Green L3	Sept. 28, 2021	WS-PVC3631-A.pdf
Green L4	Sept. 28, 2021	WS-PVC3735-A.pdf
Green Field Lens (Cylinder)	Sept. 28, 2021	WS-PVC3736-A.pdf

Entire Camera - Red

Description	Date	File
Final Inspection - Red	Jan. 3, 2022	WS-PVC3964-A.pdf

Camera Coatings - Red

Description	Date	File
Coating Inspection	Nov 23, 2021	WS-PVC4240-A.pdf
Camera Throughput Calculation	Received May 18, 2022	WS3088-KPF RED Coating.xlsx

Individual Lenses - Red

Description	Date	File
Red L1 (Asphere)	Feb 19, 2021	WS-PVC3848-A.pdf
Red L2	Jan 25, 2021	WS-PVC3797-A.pdf
Red L3	Dec. 3, 2020	WS-PVC3734-A.pdf
Red L4	Dec. 3, 2020	WS-PVC3733-A.pdf
Red Field Lens (Cylinder)	Sept. 28, 2021	WS-PVC4151-A.pdf

Green Camera Pre-Ship Compliance

Ref #	KPF Requirement Topic	KPF Requirement Text	Verification Method	Compliant?
1	Pass band	Green: 445 nm to 599 nm Red: 598 nm to 869 nm	Inspection, Analysis	Yes, described in Justificative Report. Wavelengths verified in Zemax file.
2	Throughput	The end-to-end throughput requirements for each of the camera units, not including the Grism, are shown in Table 2. These values refer to average performance over the entire camera field, presuming unpolarized light.	Test	Yes, described in coating inspection report WS-PVR1155-A.
3	Image quality and stability	The imaging specifications are shown in Table 3. Imaging requirements include the design residual, alignment, fabrication and environmental tolerances and may be met with compensation. Because each channel’s VPHG disperses nearly parallel-beam incident light at an approximate pupil to the camera, the imaging performance requirements are chromatic, that is the camera design will only achieve geometric blur requirements when tested at the actual wavelength associated with a given location on the detector. These performance requirements apply to all of the output objects as defined by the KPF Reformatter unit. The Reformatter’s output fields are also given in the full spectrograph system Zemax optical model. A Zemax model is also provided with point source fields at its output in place of the Reformatter fields. These performance requirements apply to the Camera at its operating environment, with the CCD sensor at its cryogenic temperature (-110C +/- 0.1 C TBC) and held within an isothermal radiative environment at 20C +/- 0.1 C. These performance requirements are defined separately for: a) rms spot size calculated in the spectral and cross-spectral directions separately, and b) inside and outside the 1-Free-Spectral-Range (1FSR) area of the CCD The 1FSR range is defined in Table 3a for each of the nine orders defined in the Zemax design. Wavelengths in a particular order are considered to fall inside or outside of 1FSR if they are between the cut-on and cut-off wavelengths defined in that order. The same requirements will be met for both the green and red cameras.	Test	Yes, described in final inspection report WS-PVC3963-A.
4	'Nice to have' goals	Imaging Performance Goals for KPF Science KPF radial velocity science performance may benefit by considering these imaging optimization goals that mitigate unwanted perturbations to the PSF centroid location. Goals for PSF symmetry Goal: The shape of the PSFs across a single order should be symmetric about the center of the order Cause: Pupil variations may cause the centroid to shift differently for each wavelengths PSF. If there is PSF symmetry about an orders’s center, then the average shift of all spots across an order will be minimized because spots will shift in opposite directions across the centerline Goal for PSF similarity Goal: The shape of the PSF within a single order should be similar. Cause: Observed spectra will shift within an order at different observing epochs. If PSF similarity exists within an order, then a PSF’s centroid will appear consistent at different epochs.	Analysis	Yes Within Justificative Report they claim they meet these goals because they're using the prescription that KPF provided which was based on these goals, and that any asymmetries are generated in the spectrometer and not within the camera (seems reasonable)
5	Focal Length	The effective focal length in the x-direction (EFLX in Zemax) at the center of the field shall be 495 mm ± 0.25% (TBC), for both green and red cameras. The effective focal length in the y-direction (EFLY in Zemax) at the center of the field shall be within 5mm of the EFLX value. These values may be different from previous optical prescriptions of the cameras, when focal length may not have been well specified.	Inspection, Analysis	Yes, described in final inspection report WS-PVC3963-A.
6	Camera unit Definition	The Camera Unit consists of three separate subassemblies, the lens barrel assembly (LBA), the field lens assembly (FLA) and the Grism Mount Assembly (GMA). The FLA will connect after delivery to the CCD cryostat to form a vacuum sealed unit. The cryostat is attached to the camera assembly to form a functional Camera. The Grism Mount Assembly attaches to the LBA.	Inspection	Yes, met by design. Described in Green Camera Mechanical report (WS3088-001-RAP002-A)
7	Camera unit ICD	The Camera Mechanical ICD shows interface details for joining the Camera to the optical bench mount and to the detector cryostat. The camera unit shall include an alignment cube to allow for metrology during camera integration and performance testing as well as for spectrograph alignment & integration. The camera unit shall include features to facilitate lifting and lowering the camera barrel and assembly.	Inspection	Yes, ICD pages are shown in camera final inspection report WS-PVC3963-A with majority of dimensions verified for as-built part. Final WL mechanical model verified within KPF optical bench model.
8	Camera unit vacuum compatibility	All elements and regions of the Camera Unit shall be constructed for compatibility with repeated evacuation from atmospheric pressure to high-vacuum conditions, i.e. all internal cavities shall be vented (the purge port can be considered a way to vent the camera main internal volume). All elements and regions shall use clean, high-vacuum compatible materials, including any bearings.	Inspection	Yes, met by design. Winlight also vacuum-tested camera mechanical assembly before installation of optics (Justificative Report said they would do this at 90C)
9	Camera unit mass	The estimated total mass of the Camera Unit, including the mounted GMA and the FLA, shall not exceed 90 kg ±10% without the notification and approval of KPF.	Inspection	Yes, described in final inspection report WS-PVC3963-A.
10	Camera unit – natural frequency	The mounted Camera Unit assembly, including the grism assembly, shall have a natural harmonic frequency exceeding 100 Hz.	Analysis	Yes, described in Green Camera Mechanical report (WS3088-001-RAP002-A).
11	Camera unit – Grism setting	The Grism Specification Drawings describe the Grism elements and their positioning requirements, form and mass properties. The final mounting angle in the Grism dispersion plane with respect to the Camera axes will not be known to better than +/-1 degree before the Grism is produced and examined. The Grism mount must accommodate the ability to set the dispersion mounting angle to a precision of 0.1 degree using fixed adjustment (such as shims) and not using a mechanism.	Inspection	Yes, met by design.
12	Lens Barrel and Field Lens Assemblies Materials	The Camera Unit shall be designed using materials to provide thermal compensation so that optical performance over the specified thermal operation range will be satisfied. Lenses must use densified coatings or equivalent to ensure satisfaction of operational vacuum and humidity requirement. Magnesium Fluoride coatings may not be used on the Field Lens due to the potential of damage by condensation.	Analysis	Yes. Athermalization met by design. Justificative report mentions use of densified coatings and avoidance of MgF2. Emails about coatings describe densified coatings.
13	Focus Method & Access	The Camera Unit Design shall allow for adjustment of the optical focus on the CCD sensor to compensate for as-built compensation within the Camera optics, as-built defocus errors in the spectrograph optics, and for variations in atmospheric operating and test conditions (sea-level, mountain-top, high vacuum). The method of focal adjustment is to vary the axial positioning of the FLA-cryostat assembly with respect to the LBA. The focus adjustment shall use fixed spacers and not an adjusting mechanism and not require removing the cryostat from the Camera or exposing the camera internals to the outside environment.	Inspection	Yes, met by design.
14	GMA Integration and Alignment	The GMA shall be integrated with the LBA. They shall be relatively aligned to the nominal separations defined in the green and red camera optical prescriptions. The nominal separations may be updated slightly if the camera optical prescription changes, or if the KPF spectrometer prescription changes. The alignment tolerances shall be within 0.2mm in x,y,z, and 0.05 degrees in pitch, yaw, and clocking. Verification of the final separation may be done using mechanical measurements. Note that the provided grism contains a grating, and the grating substrate edges may not be parallel to the grating grooves, by up to 1 degree error. The prism grooves will be well aligned to the prism, therefore when the grism is aligned to its nominal clocking position (based on the grooves), the grating substrate may be clocked by up to 1 degree. The GMA mount must have sufficient clearance to accept this possible 1 degree error of the grating substrate. KPF will have knowledge of this angle error several months before the grism is delivered to Winlight.	Inspection	Description given in Winlight final report is "with respect to camera optical axis" which must be a typo as that is mechanically impossible. Will ask Winlight. If numbers given within final report are "with respect to nominal" (as I suspect) then they easily meet our alignment tolerances.
15	GMA Alignment Adjustment	The Camera Unit Design shall allow for adjustment by the customer of the GMA with respect to the LBA, in pitch, yaw, and clocking directions. The resolution of the adjustments shall be less than 0.03 degrees in pitch, yaw, and clocking. The range of the adjustments shall be at least ±0.4 degrees, in pitch, yaw, and clocking, with the ranges centered on the nominal angular position of the GMA as defined in the prescriptions.	Inspection	Yes, met by design.
16	Optical Scattering, Baffling & Cleaning - Stray light	The camera design shall minimize stray light propagation and scattering and exclude outside light. The outer edges of lenses, and any lens barrel and lens clamp surfaces that are visible to the focal surface shall be coated with low reflectivity and low scatter material having < 5% TIS that is compatible with adjacent materials and operating at clean high vacuum (Total Mass Loss (TML) < 1% and Collected Volatile Condensable Material (CVCM) < 0.1%). Surface treatments shall not be hygroscopic, including any coatings to reduce stray light. An inorganic black anodization treatment is acceptable. Also, an appropriate high-temperature vacuum bake of anodized parts may be done before camera part assembly to remove sulfuric acid outgassing. A low outgassing paint is also acceptable, such as Aeroglaze Z306 with vacuum baking. Baffle apertures should be considered (TBD) in the lens assembly to prevent direct scatter paths from barrel edges to the focal plane. Barrels and extended surfaces may also be grooved to prevent grazing surfaces for incident light.	Inspection	Justificative report said they would do these things and also put mechanics through thermal-vac cycle.
17	Optical Scattering, Baffling & Cleaning - Roughness	Optical elements shall be polished to a low scatter surface roughness (< 10Å RMS isotropic).	Inspection	Yes, all lens report show < 1nm RMS (< 10 A RMS)
18	Optical Scattering, Baffling & Cleaning – FLW planar extrusion	The field lens shall include a planar extension of at least 10 mm in radius beyond the working clear aperture. The extension and lens edges shall be coated with low reflectivity and low scatter material having < 5% TIS materials and operating at clean high vacuum.	Inspection	Yes, met by design. We agreed with WL's assessment in the Justificative Report to not apply the coating to the lens edges.
19	Optical Scattering, Baffling & Cleaning – Cleanliness	Particulate cleanliness Level 300 shall be maintained within the lens barrel assembly. The focus scheme shall not allow for the direct contamination of the lens barrel interior with particulate matter. Particulate cleanliness Level 500 shall be maintained on external optical surfaces.	Inspection	Likely OK, but we don't have any documentation from WL saying they did these things
20	Ghost reflections	Ghost reflections within the working image field shall not exceed an irradiance of 10-5 relative to the incident object irradiance, over more than 1% of the entire CCD sensor area (~60 x 60 mm).	Analysis	Met by analysis in Justificative Report.
21	Cleaning procedure	Cleaning procedures for supplied components shall be compatible with materials, cleanliness levels, and vacuum exposure, where required. Cleaning procedures shall be specified prior to production.	Inspection	Nothing from Winlight on these (yet?).
22	Sealing Gaps in Camera Unit	The gaps between the GMA and LBA, and also the LBA and FLA, should be sealed to keep out most light and contamination. The seal does not need to be vacuum-tight. The seal could be made with a simple labyrinth design, or a flexible bellows, or some other definitive mechanical method.	Inspection	Met by design, justificative Report describes chicanes.
23	Clear Aperture	Optics and mounts within the lens shall be oversized so that no vignetting occurs if the chief ray at the entrance pupil, compared to its ideal location, is shifted laterally by +/- 0.5 mm and in angle by +/- 5 arcminutes.	Analysis	Met by design, analysis described within Justificative Report.
24	Shipping	The camera (GMA, LBA, FLA) will be delivered as a complete unit, rather than in separate pieces. The camera shall be provided with protective covers for both input and output apertures.	Inspection	Yes, described in final inspection report WS-PVC3963-A.
25	LBA Optical & Mechanical Interface	The Camera Mechanical ICD shows the Lens Barrel assembly mounting interface requirements including the optical axis location, and the structural mounting scheme, a six-point kinematic interfaces to Zerodur shim stacks. The Grism location and interface specifications are shown in the Mechanical ICD. The LBA shall be provided with protective covers for both input and output apertures.	Inspection	Yes, ICD pages shown in WS-PVC3963-A report with majority of dimensions verified for as-built part. Final WL mechanical model also verified within KPF optical bench model. Justificative Report shows shipping cover designs.
26	FLA Optical & Mechanical Interface	The Camera Mechanical ICD shows a Field Lens Assembly interface requirements including the structural mounting, positioning, alignment, metrology and focusing features. The FLA shall be removable, and replaceable such that all performance requirements are still met. KPF would like the cryostat to be installed on the camera without needing to dismount the camera from the spectrograph, and will give information about the cryostat installation procedure and tooling (TBD).	Inspection	Yes, ICD pages shown in WS-PVC3963-A final report with majority of dimensions verified for as-built part. Final WL mechanical model also verified within KPF optical bench model. Cryostat installation procedure not expected to require additional information from Winlight.
27	FLA - Radioisotope Content	The FLA lens shall limit the use radioactive coatings or materials. Coatings shall have U ≤ 80 ppm, Th ≤ 250 ppm, and K ≤ 3.0 % (by weight), assuming a total coatings thickness of 100 μm. This will likely rule out using ThF4 and ThOF2. Glass materials shall not include elements with significant natural radioactive isotope content, such as K,U and Th.	Inspection	WL said they would pass this info on to the coating vendors. No documentation provided on what materials actually used (but this is not typically provided). Likely OK.
28	FLA - Cryo-Vacuum operation	The camera optical performance requirements shall be met when the FLA is subject to vacuum and the CCD is operating at cryogenic temperatures. The field lens is used during laboratory testing under a pressure difference from external atmospheric pressure on the lens barrel side to high vacuum (10-6 mbar) on the sensor cryostat side. The field lens may also be subject to internal pressurization during cryostat venting operations, not exceeding 1.33 atmospheres. Consequently, the field lens assembly shall include high-vacuum sealing features to the cryostat and to the field lens and shall accommodate the possibility of internal overpressure. The FLA vacuum total vacuum seal leak rate shall not exceed 10-8 mbar liter sec-1 under 1 atm external pressure. The field lens assembly shall be made with best practice for safe cryogenic vacuum or pressure operations and shall be verified by analysis or test to survive the pressure conditions. The lens shall not have any internally radiused steps unless approved by KPF, and all surfaces shall be polished or acid-etched. The vacuum side of the field lens will be located at approximately 5 mm from the cryogenic CCD active face that operates at -110°C. Consequently, the field lens will operate substantially below ambient temperature. The mounting surface to which the field lens assembly is attached will operate at a temperature shown in the environmental specifications. The operational temperature or pressure-gradient environments shall not degrade the Camera Unit’s operational optical performance requirements.	Test, Analysis	Yes. Vacuum leak rate tested, described in camera final report (WS-PVC3963-A). Temperature gradient across field lens analyzed within the Justificative Report.
29	FLA – Stress limit	Stress within the field flattener lens shall be less than 4.44 MPa for long term loads (5 years). For analysis, assume load is 1 atmosphere of external pressure. Stress within the field flattener lens shall be less than 5.55 MPa for short term loads (12 hours). For analysis, assume load is 1.3 atmospheres of internal pressure. Evaluate maximum tensile stress.	Analysis	Yes. Winlight checked this in their mechanical Justificative Report. Chris Smith also did analysis on KPF side.
30	Environmental specification	All specifications (throughput, imaging, etc.) must be met over the operational environmental range. The cameras must still be able to perform to specifications when returned to operational ranges after being exposed to the survival environmental range. The throughput must meet specifications after being exposed to the operational environments for 10 years. The camera unit as packed for shipment may be subject to shock, thermal and pressure conditions. The camera units shall be handled & shipped in such a way as to not exceed the specified survival environment. The survival range may be modified to reflect expected shipping conditions. Bonded lenses shall be subject to an analysis and test program for like materials, configuration and environmental conditions as expected for the Camera lens elements. Bonded lens assemblies shall be verified as environmentally sound by test using three temperature cycles through the survival temperature range at a slew rate of 10 C/hour, with each cycle including thermal soaks at the extreme temperature limits of no less than 12 hours.	Analysis	Yes. Justificative Report says these conditions taken into account throughout the various analysis. They did not quote on a bonding test program, and did not undertake one, so last paragraph no longer applies.

Winlight PDR (December 20, 2019)

WL answers to several questions in table below: KPF camera - questions answers - 14-04-2020.docx

For reference, latest camera models (in SolidWorks format) are also in the vault:

Latest Winlight Data Pack - Green:

Description	File	Email Date for File	Comments
Green camera justificative report	WS3088-001-DJD001-B Green Justificative design report.pdf	January 3, 2020	Latest version
Green camera optical tolerancing	WS3088-001-RAP001-A- Green camera optical tolerancing.pdf	December 19, 2019	Latest version
Green camera mechanical report	WS3088-001-RAP002-A- KPF camera mechanical report.pdf	January 3, 2020	Latest version
Green STEP file of camera assembly	ws3088-CAO-green-cam-D.stp	June 26, 2020	Latest version
Green camera overview drawing	ws3088-110-int1-D.pdf	July 6, 2020	Latest version
Green camera Zemax	WS3088-001-ZMX001- GREEN CAMERA DJD.zmx	December 20, 2019	Latest version

Latest Winlight Data Pack - Red:

Description	File	Email Date for File	Comments
Red camera optical justificative report	WS3088-001-DJD002-A RED Justificative design report.pdf	January 21, 2020	Latest version
Red camera optical tolerancing	WS3088-001-RAP003-A- Red camera optical tolerancing.pdf	January 21, 2020	Latest version
Red camera mechanical report	WS3088-001-RAP004-A- KPF RED camera mechanical report.pdf	January 21, 2020	Latest version
Red STEP file of camera assembly	ws3088-CAO-red-cam-D 29-06-2020.stp	July 6, 2020	Latest version
Red camera overview drawing	ws3088-210-int1-C.pdf	July 6, 2020	Latest version
Red camera Zemax	WS3088-001-ZNX002-A - RED CAMERA.zmx	January 21, 2020	Latest version

APPLICABLE DOCUMENTS

Winlight Ref	Title	Document	File source for this link
DA1	Purchase order
DA2	Statement of work
DA3	KPF camera requirements	KPF Camera Spec v6.docx
DA4	KPF camera interface document	KPF-CAM-ICD-001 Rev 01 KPF Camera Mechanical ICD.PDF	Approved drawings page
DA5	Zemax archive	128 - KPF Post-PDR Layout - without reformatter.zar	This is the file we sent them at the start of the study. They have modified it to optimize the cameras (but have only changed the cameras).
DA6	Technical offer reference	ofws1635-C - KPF green camera.pdf	email

CAMERA GLASS BLANK INSPECTION REPORTS

Winlight Ref	Description
WS-PVR1003-A	Corning 7980
WS-PVR1015-A.pdf	Ohara S-FSL5Y
WS-PVR1016-A.pdf	Ohara PBM2Y (200mm diameter)
WS-PVR1017-A.pdf	Ohara PBM2Y (240mm diameter)

Winlight Pre-Review Data Pack (archive only):

Description	File	Comments
Green camera justificative report	WS3088-001-DJD001-A Green Justificative design report.pdf	now -B
Green camera optical tolerancing	WS3088-001-RAP001-A- Green camera optical tolerancing.pdf
Red camera optical tolerancing	WS3088-001-RAP003-A- Red camera optical tolerancing.pdf

KPF Compliance Matrix

Ref #	KPF Requirement Topic	KPF Requirement Text	WL Report	WL Compliance?	KPF Lead	KPF Lead Sign-off: OK/NO Green	KPF Lead Sign-off: OK/NO Red	KPF Notes
1	Pass band	Green: 445 nm to 599 nm Red: 598 nm to 869 nm	Green Optical	Yes	Steve	OK	OK	Wavelengths verified in WL Zemax files.
2	Throughput	The end-to-end throughput requirements for each of the camera units, not including the Grism, are shown in Table 2. These values refer to average performance over the entire camera field, presuming unpolarized light.	Green Optical	Yes	Steve	OK	OK for PDR. Would like to see coating curves on actual glass types as WL gets them.	Green: showed measured curves and all OK. Red: showed measured curves for FS and OK For other glasses only have theoretical curves, and not specific curves for each glass type, only for a range of indicies.
3	Image quality and stability	The imaging specifications are shown in Table 3. Imaging requirements include the design residual, alignment, fabrication and environmental tolerances and may be met with compensation. Because each channel’s VPHG disperses nearly parallel-beam incident light at an approximate pupil to the camera, the imaging performance requirements are chromatic, that is the camera design will only achieve geometric blur requirements when tested at the actual wavelength associated with a given location on the detector. These performance requirements apply to all of the output objects as defined by the KPF Reformatter unit. The Reformatter’s output fields are also given in the full spectrograph system Zemax optical model. A Zemax model is also provided with point source fields at its output in place of the Reformatter fields. These performance requirements apply to the Camera at its operating environment, with the CCD sensor at its cryogenic temperature (-110C +/- 0.1 C TBC) and held within an isothermal radiative environment at 20C +/- 0.1 C. These performance requirements are defined separately for: a) rms spot size calculated in the spectral and cross-spectral directions separately, and b) inside and outside the 1-Free-Spectral-Range (1FSR) area of the CCD The 1FSR range is defined in Table 3a for each of the nine orders defined in the Zemax design. Wavelengths in a particular order are considered to fall inside or outside of 1FSR if they are between the cut-on and cut-off wavelengths defined in that order. The same requirements will be met for both the green and red cameras.	Green Optical	Yes	Steve	OK	OK	Analysis is clear and echelle direction spots look good. Cross-dispersion OK; see slides "Camera spot sizes and cross-talk.pptx" from Feb 26th 2020 weekly meeting.
4	'Nice to have' goals	Imaging Performance Goals for KPF Science KPF radial velocity science performance may benefit by considering these imaging optimization goals that mitigate unwanted perturbations to the PSF centroid location. Goals for PSF symmetry Goal: The shape of the PSFs across a single order should be symmetric about the center of the order Cause: Pupil variations may cause the centroid to shift differently for each wavelengths PSF. If there is PSF symmetry about an orders’s center, then the average shift of all spots across an order will be minimized because spots will shift in opposite directions across the centerline Goal for PSF similarity Goal: The shape of the PSF within a single order should be similar. Cause: Observed spectra will shift within an order at different observing epochs. If PSF similarity exists within an order, then a PSF’s centroid will appear consistent at different epochs.	Green Optical	Yes	Steve	OK	OK	They claim they meet these goals because they're using the prescription that KPF provided which was based on these goals, and that any asymmetries are generated in the spectrometer and not within the camera (seems reasonable)
5	Focal Length	The effective focal length in the x-direction (EFLX in Zemax) at the center of the field shall be 495 mm ± 0.25% (TBC), for both green and red cameras. The effective focal length in the y-direction (EFLY in Zemax) at the center of the field shall be within 5mm of the EFLX value. These values may be different from previous optical prescriptions of the cameras, when focal length may not have been well specified.	Green Optical	Yes	Steve	OK	OK	Yes: the design meets these values, and the tolerance analysis shows they are comfortably within tolerance.
6	Camera unit Definition	The Camera Unit consists of three separate subassemblies, the lens barrel assembly (LBA), the field lens assembly (FLA) and the Grism Mount Assembly (GMA). The FLA will connect after delivery to the CCD cryostat to form a vacuum sealed unit. The cryostat is attached to the camera assembly to form a functional Camera. The Grism Mount Assembly attaches to the LBA.	Green Optical	Yes	Steve/Chris	OK	OK
7	Camera unit ICD	The Camera Mechanical ICD shows interface details for joining the Camera to the optical bench mount and to the detector cryostat. The camera unit shall include an alignment cube to allow for metrology during camera integration and performance testing as well as for spectrograph alignment & integration. The camera unit shall include features to facilitate lifting and lowering the camera barrel and assembly.	Green Optical	Yes	Chris
8	Camera unit vacuum compatibility	All elements and regions of the Camera Unit shall be constructed for compatibility with repeated evacuation from atmospheric pressure to high-vacuum conditions, i.e. all internal cavities shall be vented (the purge port can be considered a way to vent the camera main internal volume). All elements and regions shall use clean, high-vacuum compatible materials, including any bearings.	Optical	Yes	Steve/Chris/Kodi	OK	OK	SG: their justification list in the report is reasonable. Also, mech report calls out grism rotation bearings as vac compatible. Haven't checked the SW assembly in detail yet to look for air pockets, or make sure all bolts are vented, etc.
9	Camera unit mass	The estimated total mass of the Camera Unit, including the mounted GMA and the FLA, shall not exceed 90 kg ±10% without the notification and approval of KPF.	Green Optical	Yes	Chris			SG: Note green camera is 95.2 kg, red camera is 90 kg. Difference might be due to L4 glass type: Green L4 is 1.44x heavier than Red L4.
10	Camera unit – natural frequency	The mounted Camera Unit assembly, including the grism assembly, shall have a natural harmonic frequency exceeding 100 Hz.	Green Optical	Yes	Chris
11	Camera unit – Grism setting	The Grism Specification Drawings describe the Grism elements and their positioning requirements, form and mass properties. The final mounting angle in the Grism dispersion plane with respect to the Camera axes will not be known to better than +/-1 degree before the Grism is produced and examined. The Grism mount must accommodate the ability to set the dispersion mounting angle to a precision of 0.1 degree using fixed adjustment (such as shims) and not using a mechanism.	Green Optical	Yes	Steve	Likely OK (need to check model)	Likely OK (need to check model)	Clocking: Worst off-plane angle for VPH gratings was 3.5 arcmin, much less than the 1 deg KOSI had given as a worst case (and the WL mount design allows for). Therefore OK for clocking. Yaw angle needs to be adjusted to +/- 1.25 deg based on ghost analyses. Conveyed to WL on April 13 2020. Do we need to angle front flat face on green grism mount for stray light?
12	Lens Barrel and Field Lens Assemblies Materials	The Camera Unit shall be designed using materials to provide thermal compensation so that optical performance over the specified thermal operation range will be satisfied. Lenses must use densified coatings or equivalent to ensure satisfaction of operational vacuum and humidity requirement. Magnesium Fluoride coatings may not be used on the Field Lens due to the potential of damage by condensation.	Green Optical	Yes	Steve	OK	OK	They don't show analysis wrt to the thermal compensation part of the requirement. SG will check that regardless in Zemax. Coating part of this requirement seems OK.
13	Focus Method & Access	The Camera Unit Design shall allow for adjustment of the optical focus on the CCD sensor to compensate for as-built compensation within the Camera optics, as-built defocus errors in the spectrograph optics, and for variations in atmospheric operating and test conditions (sea-level, mountain-top, high vacuum). The method of focal adjustment is to vary the axial positioning of the FLA-cryostat assembly with respect to the LBA. The focus adjustment shall use fixed spacers and not an adjusting mechanism and not require removing the cryostat from the Camera or exposing the camera internals to the outside environment.	Green Optical	Yes	Chris
14	GMA Integration and Alignment	The GMA shall be integrated with the LBA. They shall be relatively aligned to the nominal separations defined in the green and red camera optical prescriptions. The nominal separations may be updated slightly if the camera optical prescription changes, or if the KPF spectrometer prescription changes. The alignment tolerances shall be within 0.2mm in x,y,z, and 0.05 degrees in pitch, yaw, and clocking. Verification of the final separation may be done using mechanical measurements. Note that the provided grism contains a grating, and the grating substrate edges may not be parallel to the grating grooves, by up to 1 degree error. The prism grooves will be well aligned to the prism, therefore when the grism is aligned to its nominal clocking position (based on the grooves), the grating substrate may be clocked by up to 1 degree. The GMA mount must have sufficient clearance to accept this possible 1 degree error of the grating substrate. KPF will have knowledge of this angle error several months before the grism is delivered to Winlight.	Green Optical	Yes	Steve	OK	OK for PDR. Will suggest PEEK for next project phase.	Seems OK. The concerns of the last paragraph (the 1 degree clocking of the grating) are no longer a concern. Note they have chosen PTFE (Teflon) pads to support the prism. Likely we should change these to PEEK to avoid creep?
15	GMA Alignment Adjustment	The Camera Unit Design shall allow for adjustment by the customer of the GMA with respect to the LBA, in pitch, yaw, and clocking directions. The resolution of the adjustments shall be less than 0.03 degrees in pitch, yaw, and clocking. The range of the adjustments shall be at least ±0.4 degrees, in pitch, yaw, and clocking, with the ranges centered on the nominal angular position of the GMA as defined in the prescriptions.	Green Optical	Yes	Steve	OK	OK	All ranges > +/- 0.4 degrees. Yaw angle needs to be adjusted to +/- 1.25 deg based on ghost analyses. Conveyed to WL on April 13 2020. Resolution on both clocking and pitch/yaw adjustments ~10x finer than we asked for here. Note for WL: min increment for clocking is 0.03 deg in DJD, 0.003 in mechanical document. Which one is the typo?
16	Optical Scattering, Baffling & Cleaning - Stray light	The camera design shall minimize stray light propagation and scattering and exclude outside light. The outer edges of lenses, and any lens barrel and lens clamp surfaces that are visible to the focal surface shall be coated with low reflectivity and low scatter material having < 5% TIS that is compatible with adjacent materials and operating at clean high vacuum (Total Mass Loss (TML) < 1% and Collected Volatile Condensable Material (CVCM) < 0.1%). Surface treatments shall not be hygroscopic, including any coatings to reduce stray light. An inorganic black anodization treatment is acceptable. Also, an appropriate high-temperature vacuum bake of anodized parts may be done before camera part assembly to remove sulfuric acid outgassing. A low outgassing paint is also acceptable, such as Aeroglaze Z306 with vacuum baking. Baffle apertures should be considered (TBD) in the lens assembly to prevent direct scatter paths from barrel edges to the focal plane. Barrels and extended surfaces may also be grooved to prevent grazing surfaces for incident light.	Green Optical	Yes	Tim	TBD	TBD	TM: Their approach to blacken all surfaces and put threads on all cylinders meets our reqs. They propose to not blacken outer edges of lenses, but their argument that the edges aren’t both visible to the focal surface and illuminated by input light is reasonable. Likewise, their planned baffles do not entirely prevent direct paths between barrel surfaces and focal surface. With analyzed and found two instances of barrel surfaces that are both visible to the focal surface and illuminated by input light from non-m=1 VPH orders. We presented this to WL, and they agree to review these instances.
17	Optical Scattering, Baffling & Cleaning - Roughness	Optical elements shall be polished to a low scatter surface roughness (< 10Å RMS isotropic).	Green Optical	Yes	Tim	OK	SG: They don't show a sfc roughness plot for BSL7Y, but comment that it can meet the requirement.	TM: Historical measurements show they meet spec.
18	Optical Scattering, Baffling & Cleaning – FLW planar extrusion	The field lens shall include a planar extension of at least 10 mm in radius beyond the working clear aperture. The extension and lens edges shall be coated with low reflectivity and low scatter material having < 5% TIS materials and operating at clean high vacuum.	Green Optical	No But the aim of the requirement is fulfilled, accepted by customer during PDR meeting	Tim	OK	SG: Same analysis and conclusion as Green case.	TM: Agreed
19	Optical Scattering, Baffling & Cleaning – Cleanliness	Particulate cleanliness Level 300 shall be maintained within the lens barrel assembly. The focus scheme shall not allow for the direct contamination of the lens barrel interior with particulate matter. Particulate cleanliness Level 500 shall be maintained on external optical surfaces.	Green Optical	Yes	Tim	OK	SG: OK	TM: Okay by process
20	Ghost reflections	Ghost reflections within the working image field shall not exceed an irradiance of 10-5 relative to the incident object irradiance, over more than 1% of the entire CCD sensor area (~60 x 60 mm).	Green Optical	Yes	Tim	OK	SG: OK	TM (Green): unchanged since previous reports. They correctly point out that KPF is responsible for ghosts due to reflections outside of the camera.
21	Cleaning procedure	Cleaning procedures for supplied components shall be compatible with materials, cleanliness levels, and vacuum exposure, where required. Cleaning procedures shall be specified prior to production.	Green Optical	Yes	Tim	OK	SG: OK	okay by process
22	Sealing Gaps in Camera Unit	The gaps between the GMA and LBA, and also the LBA and FLA, should be sealed to keep out most light and contamination. The seal does not need to be vacuum-tight. The seal could be made with a simple labyrinth design, or a flexible bellows, or some other definitive mechanical method.	Green Optical	Yes	Tim	OK	SG: OK	labyrinth designs are reasonable
23	Clear Aperture	Optics and mounts within the lens shall be oversized so that no vignetting occurs if the chief ray at the entrance pupil, compared to its ideal location, is shifted laterally by +/- 0.5 mm and in angle by +/- 5 arcminutes.	Green Optical	Yes	Steve	OK	OK	Lens diameters smaller than originally expected. However, pupil mask on grating will constrain beams to be on-axis. See slides "Echelle mask.pptx" from Feb 26, 2020 weekly meeting.
24	Shipping	The camera (GMA, LBA, FLA) will be delivered as a complete unit, rather than in separate pieces. The camera shall be provided with protective covers for both input and output apertures.	Green Optical	Yes	Chris
25	LBA Optical & Mechanical Interface	The Camera Mechanical ICD shows the Lens Barrel assembly mounting interface requirements including the optical axis location, and the structural mounting scheme, a six-point kinematic interfaces to Zerodur shim stacks. The Grism location and interface specifications are shown in the Mechanical ICD. The LBA shall be provided with protective covers for both input and output apertures.	Green Optical	Yes	Chris
26	FLA Optical & Mechanical Interface	The Camera Mechanical ICD shows a Field Lens Assembly interface requirements including the structural mounting, positioning, alignment, metrology and focusing features. The FLA shall be removable, and replaceable such that all performance requirements are still met. KPF would like the cryostat to be installed on the camera without needing to dismount the camera from the spectrograph, and will give information about the cryostat installation procedure and tooling (TBD).	Green Optical	Yes	Chris
27	FLA - Radioisotope Content	The FLA lens shall limit the use radioactive coatings or materials. Coatings shall have U ≤ 80 ppm, Th ≤ 250 ppm, and K ≤ 3.0 % (by weight), assuming a total coatings thickness of 100 μm. This will likely rule out using ThF4 and ThOF2. Glass materials shall not include elements with significant natural radioactive isotope content, such as K,U and Th.	Green Optical	Yes	Steve	OK for PDR	OK for PDR	Would like to have more details on the isotope content of the coatings going forward (report only addresses the coating thickness).
28	FLA - Cryo-Vacuum operation	The camera optical performance requirements shall be met when the FLA is subject to vacuum and the CCD is operating at cryogenic temperatures. The field lens is used during laboratory testing under a pressure difference from external atmospheric pressure on the lens barrel side to high vacuum (10-6 mbar) on the sensor cryostat side. The field lens may also be subject to internal pressurization during cryostat venting operations, not exceeding 1.33 atmospheres. Consequently, the field lens assembly shall include high-vacuum sealing features to the cryostat and to the field lens and shall accommodate the possibility of internal overpressure. The FLA vacuum total vacuum seal leak rate shall not exceed 10-8 mbar liter sec-1 under 1 atm external pressure. The field lens assembly shall be made with best practice for safe cryogenic vacuum or pressure operations and shall be verified by analysis or test to survive the pressure conditions. The lens shall not have any internally radiused steps unless approved by KPF, and all surfaces shall be polished or acid-etched. The vacuum side of the field lens will be located at approximately 5 mm from the cryogenic CCD active face that operates at -110°C. Consequently, the field lens will operate substantially below ambient temperature. The mounting surface to which the field lens assembly is attached will operate at a temperature shown in the environmental specifications. The operational temperature or pressure-gradient environments shall not degrade the Camera Unit’s operational optical performance requirements.	Green Optical	Yes	Chris/Kodi
29	FLA – Stress limit	Stress within the field flattener lens shall be less than 4.44 MPa for long term loads (5 years). For analysis, assume load is 1 atmosphere of external pressure. Stress within the field flattener lens shall be less than 5.55 MPa for short term loads (12 hours). For analysis, assume load is 1.3 atmospheres of internal pressure. Evaluate maximum tensile stress.	Green Optical	Yes	Chris
30	Environmental specification	All specifications (throughput, imaging, etc.) must be met over the operational environmental range. The cameras must still be able to perform to specifications when returned to operational ranges after being exposed to the survival environmental range. The throughput must meet specifications after being exposed to the operational environments for 10 years. The camera unit as packed for shipment may be subject to shock, thermal and pressure conditions. The camera units shall be handled & shipped in such a way as to not exceed the specified survival environment. The survival range may be modified to reflect expected shipping conditions. Bonded lenses shall be subject to an analysis and test program for like materials, configuration and environmental conditions as expected for the Camera lens elements. Bonded lens assemblies shall be verified as environmentally sound by test using three temperature cycles through the survival temperature range at a slew rate of 10 C/hour, with each cycle including thermal soaks at the extreme temperature limits of no less than 12 hours.	Green Optical	Yes	Chris

	Open Technical Issues (as of Sept 23 2019):
1	What is center of mass of cameras? We will accept knowing a range rather than an exact value. KPF must supply Winlight an updated cryo COM first. (This is time-critical.)
2	KPF requested more range in the GMA mechanical adjustment, in both clocking and tilt. (19 July 17 email) Waiting on response.
3	KPF suggested notional baffles inside cameras, based on stray light paths outside of the cameras, and asked for response (19 July 12 email) Waiting on response.

	TBCs in the latest KPF spec:
1	EFL-x at center of field shall be 495 mm ± 0.25% (TBC)
2	CCD sensor operates at -110C +/- 0.1 C TBC
3	Survival Temperature -33 to +71 C (TBC)

Winlight Final Proposal - Feb 7 2019

ofws1635-C - KPF green camera.pdf

ofws1666-C - KPF red camera.pdf

Summary - WL camera proposals 7feb2019.pptx

Summary of proposals.xlsx (financials)

2839-KPF inspection - camera-cryo align verif from Winlight.ppt

2839-KPF grism roll setting - proposed by Winlight.ppt

Meeting notes from Dec 12 2019 telecon with WL:

SOW updates since Dec2017 proposal - v3 - with mtg notes -WS NOTES 1.docx

Documents sent to Winlight for updated proposal - Dec 2018 to Jan 2019

SOW for Winlight cameras - v2.docx

SOW updates since Dec2017 proposal - v4.docx

KPF Camera Spec v6.docx

KPF-CAM-ICD-001_Rev01 Version4 KPF Camera Mechanical ICD.PDF

Grism-to-camera alignment v1.pptx

Winlight verif of camera alone - v3.pptx

picture of L4 sharp mount contact.PDF

KPF-SPE-MEC-191 Camera Support Base.pdf

120518_FieldFlattenerLensAnalysis_Winlight.pptx

Specification for Bonding Grisms - v1.docx

KPF Post-PDR Grism Notes.pptx

KPF-CAM-MEC-110 Rev02 Green Camera Grism.PDF

KPF-CAM-MEC-111 Rev05 Green Camera Prism.PDF

KPF-CAM-MEC-210 Rev02 Red Camera Grism.PDF

KPF-CAM-MEC-211 Rev05 Red Camera Prism.PDF

KPF-CAM-MEC-112 Rev01 Green Camera Grating.PDF

KPF-CAM-MEC-212 Rev01 Red Camera Grating.PDF

PDR STUDY RESULTS Green and Red Camera

WS2950-110-CAO1-C_20171212.stp - version updated after closure meeting

Closure Meeting Discussions

Questions to Winlight - Cameras - r1 5nov2017.pdf

Green Camera

Our documents/files sent to Winlight (emailed May 20, 2015):

Description	Files
Statement of work	SHREK Camera WL study SOW r1-1.pdf
Camera specs	SHREK Camera Specifications 20my15-1.pdf
Zemax file	SHREK - 128 - f8 - for review.ZAR

Winlight's quote for the Green Camera "Pre-Design" study:

ofws1625-A Pre-design study for SHREK Camera-1.pdf

Winlight Products from Green Camera "Pre-Design" effort:

Description	Files
Technical	WS2812-001-RAP001-A -SHREK green camera prestudy.pdf
Management and Risk (includes schedule)	WS2812-001-RAP002-A -SHREK Management and risk.pdf
Manufacturing/Costing	ofws1635-A - SHREK GREEN CAMERA.pdf

Red Camera

Our documents to Winlight for an RFQ:

Description	Files
Our statement of work	SOW for SHREK Red Camera - Jan 19 2016.pdf
Our specifications	SHREK Red Camera Specification - Jan 19 2016.pdf
Red camera Zemax file sent to Winlight	Red camera prelim for WS.ZAR

Winlight documents from Red Camera RFQ effort:

Description	Files
Manufacturing of the SHREK red camera	ofws1666-A - SHREK RED CAMERA.pdf

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