Clean, in vacuum chopper assembly with enclosure constructed of stainless steel, the standard 4-slot balde is reflective and driven by a clean, magnetically coupled transmission. With the provided controller and 4-slot (heavy) reflective blade, maximum chopping frequency is about 100Hz. Other blades available, please inquire. The enclosure provides three beam path ports, one straight through and the other deviating 90 degrees (reflected.) This accessory is routinely used in systems like the vacuum spectrophotometer VUVaS. Vacuum operation in to the 10^-6 torr range. Also available in all metal sealed UHV versions.

Vacuum polarizer mount allows the user to insert and retract polarizers from the optical axis while under vacuum. The polarizer may also be rotated through > 90 degrees while under vacuum. Angle readout indicates actual position of the polarizer. Few polarizers work in the vacuum ultraviolet. This accessory fits the few commercially available Rochon type polarizers constructed of Magnesium Fluoride and working in the ~140 to 220nm wavelength range. This accessory is o-ring sealed and suitable for vacuum to 10^-6 torr. Flange connections to beamline are NW40.

Our popular prism predisperser models use fused silica prisms and their range is restricted to the non vacuum UV-Vis and IR wavelengths. To address user needs for coarse dispersion, pre wavelength selection in the vacuum range we conceived this grating predisperser. It is useful in applications requiring low stray light or separation of intense nearby energy from less intense signal of interest. The near normal incidence angle help maintain reasonable optical performance even though this unit most often works with coarse gratings. Vacuum slits are not included but are available as accessories. Some users with simple requirements may use the vacuum compatible grating predisperser as a low performance monochromator / grating drive for home built instrumentation.

The alignment accessory is useful in many applications. For example, in many applications it is important to align, determine field of view, and calibrate spectrometers and detection system. This can be challenging under vacuum conditions. The alignment accessory can also help set optimal light collection from vacuum sources (Deuterium or Hollow Cathode) with respect to emitted source energy. This accessory allows to freely float a source point at the spectrometer's entrance aperture. This enables interception of sections of a hollow cathode plasma, for instance, or, spatial confirmation of peak plasma emission. Useful for any UHV or standard vacuum spectrometer system in which repeated venting to atmospheric pressure would be required during source alignment.