Difference between revisions of "01 Feb 2019"

Revision as of 07:55, 11 March 2019

Combined Sprat/SHOC is way to go.

Working out from Nasmyth:

"Inside" Nasymyth is autoguider. This can patrol half of the field of view, and will hopefully have a focus mechanism.
Nasmyth mounting:
- James to provide details of this mounting as used on Wide Field Camera on opposite port.
- 1/4 of the field of view will be for a High Resolution Spectrograph (HRS) fibre feed
- 1/4 of the field of view with be for SPRAT/SHOC
- A cable wrap (copy of that on opposite port) will be provided. James to provide details.
- There is possibility of pneumatic supply
Deployable calibration mirror (to feed flat/arc)
Deployable slit
Field Lens
Collimator Lens
FILTER SLIDES (3). Hopefully <50mm thickness. To house maybe 5 filters each. Note one filter will need to be order blocker (4000-8000 Angstroms) for SPRAT. James to design to fit to an interface in SPRAT.
Grism Assembly
Camera Lens and CCD.

General Design Points

Filter slides need to be in collimated beam to avoid focus shifts
Try and minimise cables on/off mount. So mount control computer with instrument. Note SHOC software requires GPS feed (serial; currently using serial to USB, Amanda to check latest GPS hardware).
USB for camera rather than PCI Card
Use existing SHOC CCD readout (via andor SDK)
Use existing Apache Thrift infrastructure
LJMU responsible for all mechanism control, including filter slides
Use wiki to keep one version of documentation/files etc.

Actions:

IAS: Check/modify optical design to make space for filter slides
James: Provide details of mounting plate/wider field camera (STEP File); provide information on cable wrap being used on other port
Carel: Provide details of SHOC software to Chris Mottram so he can try and built a local copy at LJMU
Amanda: Look at trade off between deep depletion (higher red QE, higher dark current) and standard EMCCD