The Project is about the acquisition of a Noble Gas Mass Spectrometer (NGMS ). The NGMS is a magnetic sector spectrometer used for isotopic composition analysis of small samples of noble gases (He, Ne , Ar , Kr and Xe ). The system included in this proposal is able to analyze all isotopes of noble gases, but is particularly suitable for the simultaneous measurement of the two isotopes of helium mass 3 and 4 (3He and 4He).
The main components of nGMS are:
1) “Nier” ions source, designed for easy disassembly, easy change of the filament and cleaning.
2) Electromagnet mounted on roller bearings and with rotational and translational adjustment in three planes to optimize the shape and flatness of the peaks. The pole face of each collector output can be rotated independently to fine tune the focal length of each detector.
3) Electronic control systems , with the following components: ( i ) the power electronics , controlled by a computer, ( ii ) data collection for Faraday detectors and electron multipliers and ( iii ) control of the magnet.
4) Vacuum System, designed for ultra-high performance real vacuum ( UHV ). The system is made of stainless steel welds with minimum welding in both the source and the collectors. The flight tube is also made of stainless steel. The pumping of the UHV system is achieved using a 40 L/s ion pump specifically designed for pumping noble gases and a 70 L/s turbomolecular pump supported by a two stage diaphragm pump.
The detectors connected to NGMS are a multiplier for ion counting for low masses, and Faraday cage widely suppressed voltage for higher masses. The Faraday cage is connected to a switchable gain amplifier by software 1011 and 1012. The detection system also incorporates a low electrostatic mass analyzer 50 mm for extreme abundance analysis.
The most important accessory for the correct use of the NGMS is the double-entry preparation system for noble gases or gas purification system. The gas purification system consists of last cleaning line and two separate primary lines that provide a clean source of noble gases for the analysis (helium, neon, argon, krypton and xenon). The primary lines clean the gas sample before its admission for the final cleaning on the line. The final cleaning line is used for all samples and reference gases before entering the mass spectrometer. This design allows two sample introduction systems to the preparation system, for example a furnace and a laser. With These two introduction systems allow to independently evacuate using a turbomolecular “dry” pump and samples can be analyzed using one of the loads while the other is being cleaned/loaded. This increases productivity to the maximum.
The preparation system is mounted on a bench. This system uses a new solid collector technology that uses gas collectors of solid stainless steel to help reduce the volume. Manual valves used are all metal, at right angles, with mini conflat . The bench contains all electronic systems to control the preparation system, including ( i ) the turbomolecular pump controller, (ii) the ion pump controller, (iii) control unit for the supply of heating and Getter (x4) and (iv) Ion Gauge Controller.
Finally, the NGMS and the gas purification system are controlled via a PC with Windows XP Pro or later versions, an integrated computer running an operating system in real time; control software associated with each instrument. The PC with Windows XP runs the software of each instrument and is responsible for providing the user interface and monitor the performance of the instrument. The integrated PC is responsible for controlling the instrument at a low level and maintains the system´s integrity and time.
Research areas in which the NGMS be used: The application of isotope geochemistry of noble gases has many scientific applications. This provides a significant scientific equipment in investigations related to the exploration of geothermal resources advance the study of groundwater resources and reducing volcanic risk through a strengthening of the volcanology monitoring , among others. The use of this instrumentation allows multiple opening new research among which are the following : Heat flow studies in high enthalpy geothermal exploration Research on groundwater resources by noble gas isotope geochemistry Isotopic geochemistry of noble gases in volcanology