VAMPIRES:Settings

VAMPIRES Settings

Run commands on VAMPIRES computer (sonne)

Acqusition and cube-size settings

The integration time per frame, the number of frames per cube and the window size can all be set independently, but here are some guidelines.

In general, cubes should not be longer than ~1 minute, as the cube length is also the amount of time that you have to wait after pressing Abort, etc.

Maximum safe cube sizes - Cubes should not be bigger than that shown in teh following table, or nasty slowdowns / OOM errors can occur.

Window Size	Min. t_int	Recommended max frames/cube	Total t_int	Total overhead
128	5 ms	12000	60 s	12 s
256	10 ms	4000	40 s	16 s
384	14 ms	2000	30 s	18 s
512	19 ms	1000	19 s	18 s

File saving overhead For large frame sizes there is considerable time overhead in saving data after acqusition has been completed, resulting in a low duty cycle.

Polarisation considerations When in polarisation mode, it is best to have one frame per HWP position, which is often chosen to be ~1 minute.

Beamsplitter wheel

The beamsplitter wheel can be controlled via the vampires_beamsplitter command on sonne.

# move to polarized beamsplitter
vampires_beamsplitter 2

For more granular control, use the conex command directly

• Check current position: conex 8 TP
• Move to position: conex 8 PA XX where XX is the desired position angle

The most up-to-date positions are stored in the configuration file /home/lestat/code/script/conf/conf_vampires_beamsplitter.txt

#	Name	Angle
1	Open	0
2	Polarised beamsplitter cube	45
3	Open	90
4	700 nm SP beamsplitter	133.95
5	Open	180
6	50/50 beamsplitter cube	224.65
7	Open	270
8	750 nm SP beamsplitter cube	315

Differential filter wheel

The differential filter wheel can be controlled via the vampires_diffwheel command on sonne.

# move to Continuum/H-alpha pair
vampires_diffwheel 4

For more granular control, use the conex command directly

• Check current position: conex 9 TP
• Move to position: conex 9 PA XX where XX is the desired position angle

The most up-to-date positions are stored in the configuration file /home/lestat/code/script/conf/conf_vampires_diffwheel.txt

#	Camera 1	Camera 2	Angle
1	Open	Defocus lens	0
2	Open	Open	45
3	775-25	675-25	90
4	Continuum	H-alpha	135
5	Defocus lens	Open	180
6	Open	Open	225
7	675-25	775-25	270*
8	H-alpha	Continuum	315

* Position suitable for the 700nm SP / 750nm SP beamsplitters. Beamsplitter 4 (700nm SP) has the best alignment of the two.

Coronagraph/Field stops

The coronagraphs and field stops are common path with FIRST and RHEA, be mindful when moving them.

Field stop commands are run on scexao2. The recommended way to control the field stops is with the vampires_coronagraph bash TUI, which has menus for fine-alignment and adjusting focus. This calls the vampires_fieldstop command behind the scenes. This script can take x or y as sub-commands for the respective stages. Note that x and y do not correspond to the axes as seen on vControl from cam1. The Lyot stop is controlled by the VAMPIRES pupil wheel (use vControl).

⚠️ When using the focal plane masks for the coronagraph, the focus will change because of inserting glass into a converging beam. More detailed testing needs to be done, but it seems like the offset is around -6 mm

Camera Focus

There are two focusing commands, one controls the absolute focus by moving the objective lens assembly, the other controls the differential focus between cam1 and cam2 by moving cam1.

to change the focus, you can either use the interface within vControl ("Steer Im/Pup" and use the Abs+ and Abs- buttons/text field) or you can use the vampires_*focus commands

vampires_focus <command>
vampires_camfocus <command>

For example, to change the absolute focus to 16 mm

vampires_focus goto 16

Right now, the nominal focii are

param	value	unit
focus	9.11	mm
focus (coro)		mm
camfocus	9.92	mm
	376000	step