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NIBTRON Data Sheet

Ion Source Options.
Open Ion Source. (Fitted as Standard) This ion source is used for residual gas analysis and simple gas analysis applications.



Axial Beam Ion Source. This ion source is specifically for analysing either molecular beams or ion beams from an external source. The ion source has a low profile with side mounted filaments so that the source can be positioned close to the exit hole of a source of ions or molecular beam that is in line with the axis of the quadrupole. 
Cross Beam Ion Source. This source is for molecular beams that enter the ion source at right angles to the quadrupole. A clear aperture of 3,5mm avoids contact with the molecular beam. This source is normally used in applications where condensable vapors may be present within the molecular beam that could contaminate the quadrupole filter.


NIBTRON Data Sheet



NIBTRON Ion Source. This source is specially for gas analysis only and has many unique advantages to the traditional gas tight Ion Source.

.Mass Filter Options.

Single Mass Filter.  (Fitted as Standard) A Low cost single stage mass filter using cylindrical rods for low mass applications.

Saddle mounted Filter. A high precision saddle mounted mass filter is available as an option on our range of instruments. It is easily de-mounted for cleaning. This enclosed filter offers improved sensitivity, resolution and abundance sensitivity.

Dual & Triple filters. These are available based on saddle mounted mass filters, and are normally chosen for special applications or when the highest performance/resolution is required.. Available on the AX800 instrument only.

Detector Options.

Faraday Only. A Faraday plate detector for ion collection. Used mainly for higher pressure applications when greater ion currents are available for collection.

Dual Faraday/Channeltron. The Channeltron (SEM) provides a high level of amplification of the ion beam and therefore provides detection of much lower ion currents. When in SEM mode the pre-amplifier can be operated at a lower gain and faster scanning speeds are possible.

Discreet SEM. A discreet dynode Electron multiplier is available on the AX800 as an alternative to the Channeltron Electron Multiplier. This has much larger surface area of secondary electron electrodes and therefore offers much longer life when operating on continuous high signal levels over prolonged periods of time. The Faraday option is not available when this device is fitted.

Pulse Counting. Provides the ultimate in detection by counting individual ions arriving at the detector.. Normally used in trace gas analysis applications where the lowest level of detection is required. A special version of the electronics is available that includes a counting pre-amplifier, system clock, counter, and interface for transferring the accumulated ion count to the quadrupole software for display. (Special order)

High Temperature Operation

Thermal Extender. Allows operation of the quadrupole whilst the analyser is at high temperature This option is available on most of our RGA instruments and has to be fitted to the analyser at the time of manufacture. It extends the back of the analyser  by approx 24 cms so the plug-on electronics is now separated from the analyser hot zone.

Filament Options

Technical Notes.

Which Filament?

The majority of our competitors use a twin filament assembly. That means that when one of the filaments blows the customer has a difficult decision. Does he replace the filament assembly throwing the remaining good filament away, or does he run on the second filament and hope it does not blow during a critical measurement when there is no back-up.

All ASI/Larimax RGA’s are fitted with two filaments. The filaments are individually replaceable. Therefore if one filament blows, that filament can be changed at a convenient time. And the other good filament remains on the analyser

Tungsten Filaments. Advantages Disadvantages
Operating temperature for Pure Tungsten approx 2200C   A good low cost general purpose filament. Life is reduced in oxidising atmospheres above 5x 10e-6mBar
Operating temperature for Thoriated Tungsten (1% Thoria) approx 1950C  Under high vacuum, below 10e-6mBar filaments will last many months and sometimes many years. Life is reduced in high partial pressures of water vapour (10e-5mBar) due to filament erosion.
  Can be used at high pressure in inert atmospheres. Tungsten filaments usually produce background peaks at mass 28 (CO) and 44(CO2).
  Can be used in Hydrogen or reducing atmospheres. Sudden exposure to high pressure above 10-2mBar of oxidising atmosphere can cause instant oxidation and burn out of filament.
  Safe to handle filaments. Will burn out instantly if switched on at atmospheric pressure.
    Can produce a catalytic action with some chemicals.


Slow evaporation of filament will cause the filament to become thinner over a very long period of time, with a reduction of operating current eventually leading to failure.

Normally recommended in medium and high vacuum systems for general-purpose residual gas analysis.

Thoria Coated Iridium. Advantages Disadvantages
  Life typically 12 months or more. More expensive than tungsten filaments.
Operating temperature approx 1400C. Runs at lower temperature and therefore lower out gassing from Ion Source. Poisonous and mildly Radio-Active. Disposable gloves and mask should be worn when handling filaments.
  Does not produce CO or CO2 and therefore these background peaks are much lower. High levels of hydrogen can cause reduction of the oxide coating with an increase in water background, and a consequent reduction in filament life.
  Can be used at high pressures in oxidising atmospheres. Severe Shock or vibration can dislodge the coating.
  Will tolerate high pressure burst. Cannot be chemically cleaned.


Normally recommended for gas analysis applications and for use at high operating pressures, especially if oxidising gases are present. Also may be preferred in UHV conditions when the lowest possible background is important.


Yttria Coated Iridium. Advantages Disadvantages
Operating temperature approx 1600C. Similar to Thoria Similar to Thoria (See Comment below)


Sometimes chosen as an alternative to Thoria because it is not Radio-active 

Yttrium Oxide absorbs CO2 and NH3 ( if present) from the atmosphere. Long term exposure may convert the oxide to the carbonate. If this happens then it may outgas large amounts of CO2. when first operated, as the carbonate is converted back to the oxide. Yttria filaments should be stored & systems vented with dry nitrogen or an inert atmosphere if possible, if prolonged exposure to atmospheric pressure is  required.

  Filaments in other materials are available to special order.



Contact Information

+44 (0)1805 625 205
Postal address
  Anglo Scientific Instruments,
  3, Devon Units, Hatchmoor Industrial Estate,
            Torrington, Devon. EX38 7HP. UK.
Electronic mail

All enquires:           angloscientific@live.co.uk