2023.02.14 - UBV/RIZ Monthly meeting

Agenda : 10:00-12:00 CET

• 10:00-10:05 (5 min) Introduction (Bruno)

• Optical design Update

  • 10:05-10:20 (15 min) RIZ optical design status (Audrey)

  • 10:20-10:35 (15 min) UBV optical design status (Michael/Manfred)

• 10:35-10:55 (20 min) Vacuum tank updates (Pablo / Jonathan)

• 10:55-11:15 (20 min) Thermal enclosure updates / discussion (Pablo/AIP)

• 11:15-11:35 (20 min) Status of the Opto-mechanical Design

• 11:35-11:40 (5 min) Coordinate system

• 11:40-11:50 (10 min) CAD Archive

• 11:50-12:00 (10 min) Situation of the management in Spain

Optical design update:

• UBV status: Work is ongoing to put every arm together, the proposition to use the same preslit design change as RIZ has been accepted, Some work on alternative collimator design also ongoing.

• RIZ status: A work to validate the manufacturability of the E. Oliva inherited design is ongoing, It seems to be the case that we have a workable solution. In the meantime we have some consulting work from B. Delabre that proposed a preslit optics change, that has been adopted. He also proposed a whole spectrograph design that is changing essentially the way the long slit aberrations are corrected using a schiefspiegler configuration (use of tilted spherical mirrors). This leads to a new overall design with new possibilities that RIZ team needs to look in detail to assess advantages incovinients.

Discussion: Both teams are advancing slowly and we are not yet in the frozen state. Main take out of the discussions are:

• Opto-mechanics design cannot start without freezing the design.

• Though it seems that RIZ/UBV follow different design path, it is common understanding that once some clear good solution is found we will try our best to make a common design.

• The possibilities to have the cameras at the bottom of the design is interesting for the opto-mechanical design

• We should do our utmost to avoid delay to the SAR.

Vacuum tank design:

• There have been advances on the aluminium square design, there is already some price tag on it (and it is not cheap)

• A new version is being studied inspired by LIGO or other developments in spain. Could be made out of steel or aluminium. study to be continued. Potentially much cheaper design.

• One important point proposed also is to have the vacuum vessel and the optical table decoupled as much as possible using flexible bellows, and also to be able to correct the orientation of the table from the outside.

• A proposal on how to keep the vacuum without vibration is on the table, wee need to convince ESO that it will work

Discussion:

• On the new design studied the buckling load on the top part could be a dimensioning feature

• Discussion with the spanish team to be organized to share experience in this field.

• Obviously this part is also dependent on a freeze of the optical design

Thermal enclosure design:

• Work on the OpenModelica model, and the concepts has progressed. One interesting new proposal is to use Peltier elements in order to be able to cool or heat with the same devices.

• The German team has now starting FEM modeling

Discussion:

• A suggestion has been to lower the number of elements of the mesh of the FEM analysis to speed things up.

CAD archive:

Work is still on going to figure out how to deal with all the different softwares. hopefully there seem to be a path forward.

Mechanical Reference System:

No problem has been spotted with the proposal made by the Geneva Team, however the effort has to be more detailed. ESPRESSO documentation will be used as a template. More over some harmonization at the level of the project lead by ​Utilisateur mentionné @Edoardo Maria Alberto Redaelli@Edoardo Maria Alberto Redaelli is needed.

Management of the Spanish contribution:

Good news here Manuel is back!

The slides presented during the meeting can be found here ​