Routine Maintenance

Maintenance Schedule

Dewar thermal cycling

There is no set requirement for dewar thermal cycling. The active charcoal getters should be capable of maintaining pressure in an operating range almost indefinitely, provided the tank stays cold. An occasional (maybe every 6 to 12 months) thermal cycle may not be a bad idea.

Note that if a dewar is ever allowed to warm up to the point where pressures rise significantly above 1e-5 Torr, it is then recommended to do a full thermal cycle including warm-up and extended pumpdown.

Mirror cleaning (guider, slicer)

We see debris on the ACAM pickoff mirror and on the slicer mirrors. These will need to be cleaned. An inaugural cleaning and corresponding procedure are pending.

The A&G system pickoff mirror should be cleaned occasionally. We will perform such a cleaning prior to 2026B and a procedure will be provided.

Other internal optics should not need cleaning.

Instrument cleaning

A damp cloth wipedown of the instrument exterior every few months is likely a good idea. A more frequent wipe down around the entrance apertures (near the slicer cover and Acam cover) is also recommended.

Arc lamp replacement

The two arc lamps are replaceable. The box design is similar to the CWI lamp box where a back cover with the lamp attached slides out, the lamp unplugs from its socket once a plastic retainer is removed.

Continuum bulb replacement

The Red continuum lamp has an internal bulb that can be replaced. Be sure to wear gloves and never bump or drop the bulb, full instructions are provided in this video, but the procedure is to remove the side panel (to the left when looking at the face with the intensity knob). While holding the bulb, release it with the two thumb screws and pull directly up. Insert the new bulb and tighten the two thumb screws and replace the panel.

The blue continuum lamp has a very long lifetime and we do not expect to need to replace it, but a replacement would require a replacement of at least the expensive light source head (a completely new unit). The procedure to do so will be provided if there is need.

Instrument glycol interconnect inspection

Instrument glycol interconnects at the 3 Andor cameras (slit-viewing and guider) should be inspected daily, as should the telescope hose interconnect on the underside of the instrument electronics rack. We have provided a separate procedure to facilitate these inspections and any servicing deemed necessary; see Plumbing — Managing Cooling Lines and Addressing Leaks.