Features:

• Grating/mirror pair optics maintains sharp sagittal focus at all wavelengths
• Each grating tuneable from zeroth order to >125nm
• Two cassettes can be loaded in the standard instrument.
• Optional laminar HeI grating for suppression of second order HeII.
• Optional chamber sizes for 3 or 4 cassettes
• Bakeable up to 120°C
• spot size < 500µm.
• Line width < 1meV.
• photocurrent HeI_α > 20nA ; HeII > 8nA.

Product Description:

SPECS is pleased to introduce the new TMM304 VUV Monochromator. This instrument uses a unique cassette-based optical design to maximise the photon flux at specific user-selectable wavelengths.

In its standard configuration the TMM304 contains two cassettes, one for HeI and the other for HeII which are selected using a linear drive. While each cassette is optimised for a particular wavelength, the gratings can be tuned via a second linear drive over a wide spectral range down to zeroth order, where light from the UV lamp is specularly reflected by the grating through the monochromator. Cassettes are also available for other wavelengths where it is desired for example to run the UV lamp on alternative gases such as neon and hydrogen.

In combination with the SPECS UV source UVS 300 and an ellipsoidal capillary, the TMM 304 system can be configured simultaneosuly with up to four stages of differential pumping and spot sizes down to 500 micrometres producing ultra-low helium partial pressures in the analysis chamber and outstanding photon fluxes.