Introduction: there are 3 main modes in Echelle :
- Echelle classic: Echelle + X-disperser + Mask (if needed)
- Echelle "long slit + X-disperser" ( no mask)
- Echelle "long slit + filter" (no X-disperser, no mask)
To setup an ECHELLE grating:
- Install requested cross disperser grism(s) in position #6 or (/and) #7
of grism wheel.
- For Ech #10 or #14, install Echelle mask in REMD path unless not
wanted by observer ( e.g. long slit).
- For Ech#9 do not use Echelle mask in REMD.
- On EMMI configuration panel declare echelle , echelle mask and cross disperser(s)
- Although the status on EMMI config panel remains "not
Echelle is in the proper position and does not need centering.
- Click Backup under File submenu.
- Focussing: run REMD_all_tec_SetFoc to tune focus
- if cross disperser will be used, run REMD_all_tec_CheckFoc
without cross disperser (as template doesn't work with it)
and choose the option Fixed focus or focus offset according
- if long slit mode (narrow band filter and no cross disperser)
run REMD_all_tec_CheckFoc with specified
filter and no grism.
- long slit mode filters are generally
so narrow that exposure time above 300 s is recommended.
this means that focus check
will last 40 mn at least.
- The best focus temperature will be automatically reported into the REMD
focus popup window.
You can verify it in the next REMD_ech_cal_Arcs for instance. (Be careful
if two cross dispersers are going to be used: only the last measured best
focus will be recorded automatically).
- Leave the corresponding focus curve print out on wemmi keyboard.
- For Echelle#9 , run a wave calibration REMD_ech_cal_Arcs with
- Slit width SLIT.WID
- Slith length SLIT.LEN
- lamp LAMP1.NAME
- time LAMP1.EXPTIME
~ 120 sec.
- GRAT.NAME = Eche#9.
- Compare the RTD display to the figure which you can find in
Emmi Users's Manual section C.4.