CRE Details
-
CRE Identifier:
CRE-007
Title of CRE:
LTAO: change to separate LGS dichroic from FPRS window unit
CRE Class:
Class 1
Status
Implemented and Closed
CRE Owner
Fraser ClarkeSharepoint Link
CRE Folder (SharePoint)
Affected Documents listed in CRE
Resource Identifier Version Document Name Main Author Status More Info PDF Link HRM-DGW-3200-1000-013 A Not found in the Database New/Updated Documents listed in CRE
Resource Identifier Version Document Name Main Author Status More Info PDF Link HRM-DGW-3200-1000-013 B Not found in the Database CRE Notes
- Reviewed at CCB on 2019-02-12: This was returned for further investigation as it was not clear that the impact of the uncorrected tilted window doublet in SCAO and HC modes had been fully reviewed or included in the document – for instance the HC mask would have to increase significantly greatly increasing the radius of detectability of planets around a star. This could be a major degradation on potential science. Likewise SCAO has not had to deal with the additional dispersion previously. Conversely, if we left the window doublet normal to the beam, dispersion in the L-NGS in the LTAO mode would have to be assessed.
- Therefore we need more information on:-
- • Impact on HC mode - mask radius, reduction in potential target count…. Alexis Carlotti
- • Impact on SCAO mode – Kjetil to review with Jeff
- • Impact on LTAO mode if dichroic dispersion not compensated – Kjetil to review with Benoit and Tim
- • Re-investigate previous alternatives to the window compensating for the dichroic (Cylindrical lens, “blank” glass to replace dichroic) – Monty + Patrick maybe
- Aim is to do this in about two weeks to coincide with review of the LGSS Fixed Asterism CRE.
- Provisionally agreed at CCB on 2019-04-01 - details captured in ECN-007.
- 2019-06-05: Interface drawing HRM-3200-1000-013 has been updated to rev.B. Awaiting confirmation from FC that outstanding action items from CCB of 2019-04-01 have been addressed.
- 2019-08-13: Interface drawing HRM-DGW-3200-1000-013 has been updated to Rev.B, lodged in Sharepoint and the ICDossier and incorporated into design (reviewed at OCDR). Closed.