Gas Nozzles and Water-Cooling Mounts

gas nozzles

Introduction / overview
The water-cooling mounts described in detail in sections 9.60, 9.70, 9.80 provide a general
mechanical interface between mounted ZnSe lenses and the appropriate gas nozzle.
Three sizes of water cooled mount WMA, WMB, WMD(1) suit lenses in M11, M15 and M20 lens
cells, respectively.
Three sizes of gas nozzle:- SNA, MNA, LNA, each with a range of nozzle tips and length adaptors
to suit all standard lens focal lengths, are appropriate to the abovementioned water-cooled mounts.
The gas nozzle type ‘GNA’ remains appropriate for use with 11TF series lenses, but is no longer
recommended for general purpose use, being limited to 6 Bar gas pressure.
In some instances another ULO Optics product may be used to interface a mounted lens and gas
nozzle, avoiding the use of a water-cooled mount. Examples include FF25, FF38, CFF25, CFF38 focus
mechanisms. The appropriate water-cooled mount becomes optional for use with these items,
depending on the laser power in use.
Technical considerations
The ULO Optics gas nozzles detailed in technical data sections 9.10, 9.20, 9.30 are designed to
have several important features:
* All gas-outflow paths sealed with ‘O’ rings (including lateral adjustment screws).
* Smooth conical gas-flow path to nozzle tip.
* Adequate lateral adjustment range.
* Adequate stand-off adjustment for nozzle tip (usually +/-3mm).
* Lockable stand-off adjustment.
* Able to withstand high gas pressure.
Nozzle height adaptors / nozzle tips
Each nozzle type has a range of height adaptors allowing the basic (short) nozzle to be used with a
range of lens focal lengths.
The complete nozzle assembly is adapted to suit a particular lens type by use of one of a range of
nozzle tip lengths. This is necessary because the flange focal distance (FFD) for a lens depends not
only upon the effective focal length (EFL) but also upon the lens thickness. So, for example, an MNA
nozzle used with a 15MZLF127 lens uses height adaptor MNA/2/0605 and a nozzle tip 24mm long.
An MNA nozzle used with a (thicker) 15MHGP127 lens uses the same height adaptor, but a shorter,
22mm long, nozzle tip.
The height adaptors are gas-sealed against the nozzle body and against the related interface unit
(eg: water-cooled mount).
Standard nozzle tips, having a conical internal bore ending in a short parallel section at the gas outlet,
are designated ‘NT/01/xx’ series. These copper nozzle tips are common to ULOOptics nozzles
in the SNA, MNA, LNA ranges.
The number ‘xx’ represents a measure of the length of nozzle tip. (See data sections 9.10, 9.20, 9.30).
Product summary
Lens diameters, lens mount types, water-cooled interface units and appropriate gas nozzles are
related in table 9.01, below:

Gas Nozzle Data

Note (1): Water-cooled mount type ‘WMC’ suits mounted lenses of the ’15TF’ series only. These
lenses and mounts require specially adapted versions of the GNA series gas nozzle.
See technical data sections 21.2, 21.3.