Mass-Spectrometers for Tritium Analysis
Specialized Mass Spectrometers for Analysis Tritium Gas Mixed in "In-line" Mode
Tech Area / Field
- INS-MEA/Measuring Instruments/Instrumentation
3 Approved without Funding
All-Russian Scientific Research Institute of Non-Organic Materials named after A. Bochvar, Russia, Moscow
- NIIEFA Efremov, Russia, St Petersburg\nVNIITF, Russia, Chelyabinsk reg., Snezhinsk
- Forschungszentrum Karlsruhe Technik und Umwelt / Tritium Laboratory, Germany, Karlsruhe\nConsiglio Nazionale delle Ricerche / Instituto di Fisica del Plasma, Italy, Milan\nGeneral Atomics, USA, CA, San Diego
Project summaryThe aim of the present project is calculating and experimental motivation of possibility of development the small-dimensioned high-speed time of flight mass-spectrometer (mass-reflectron) for isotopic and chemical analysis of tritium gas mixtures, fabrication of a pilot model and test it in the technological system for the real technical feature study and operational demonstrations and reliability.
Small-dimension specialized in the fields of light gases mass spectrometer with corresponding analytical characteristics and speed, possibility of working in "in-line" is need in modern time in many fields:
- The stage of technical designing of International Thermonuclear reactor (ITER) is coming to the end. Experiments with the mixture D-T were conducted for the first time on JET installation and TFTR; separate technological installation, prototypes of "Tritium Plant" are under investigations in KfK (Germany), Ispra (Italy), JET (England), TSTA (USA) and others.
- The frames of works with tritium control in the technological systems for lazer FR is increased and corresponding technological installation is developed. The creation of blanket on the base of accelerating installations operating with H-D-T gas mixtures are under consideration and experimental technological systems are accordingly created intended for working with gas mixtures, containing isotopes of hydrogen and helium (H-D-T-3He-4He).
- The control in technological systems for regenerations of nucleus ammunitions and saturations the targets of neutron generators by the tritium is necessary The control of tritium at Atomic Stations, especially with HW reactors, and in places of storage and transportations of great amounts of tritium and etc is necessary. At present because of the absence of serial single-purpose mass spectrometers, taking into account specifics of light gases analysis and b-active tritium, for operative control in technological systems arc adapted omegatrons and quadrupole mass spectrometers, which do not as a whole suitable for analytical control of H-D-T-3He-4He gas mixtures.
It is necessary high resolving power R10%=2500 (however, 3T+-3He+ will not be separated) and high sensitivity for full isotope and chemical analyses of H-D-T-3Не-4Не mixtures, since gas mixture, except main components can contain the following admixtures: oxygen and oxides of different elements, hydrocarbons, nitrogen and its combinations, neon, argon and etc. Range of contents of admixtures can be from 10-3% to 5%. It is necessary high sensitivity in events of finding of T2 leakage. The most important requirement for analysis of tritium mixtures by mass spectrometers is an eliminating of a detectors background, caused by b-active tritium. Necessary sensitivity of instruments practically is not attainable without performing this requirement. Installation created on the base of omegatrons and quadrupole mass spectrometers do not fulfill enumerated conditions. It is possible to take into account (fully or partly) specifics of analysis of such mixtures in static mass spectrometer with the double focusing or in time of flight mass spectrometer (mass reflectron). On the first stage of work within the framework of this project it is decided to create a model of mass reflectron, having advantage in the speed and sensitivity.
It is necessary to pay attention that mass-reflectron and using it for light gases analysis - is a unique developments, not having analogues in the world. Principle of functioning of the mass-reflectron allows reducing an influence of detector background while working with the radioactive isotope of hydrogen that in quadrupole mass-spectrometer and in omegatron is impossible.
This project is stipulates on the grounds of calculating and experimental work, experience of development of mass spectrometers for isotopic and chemical analysis of light gasses by the commonwealth of VNIINM, VNIITF and NIIEFA, development and tests of a laboratory model of mass reflectron.
The work on project expects:
- calculation with the help of developed programs and choice optimum ion-optical mass-reflectron scheme;
- fabrication of pilot model of mass-reflectron and its technical parameter study in laboratory conditions on hydrogen-helium mixtures;
- test of a pilot model and its technical parameter study on tritium gas mixtures at technological installation, qualification of measurements;
- to give recommendations for capacity to work, advantages and applications of mass reflectron in the mode "in-line" in technological thermonuclear installation systems and others areas (control of leakages, ultra cleaning of helium, neutron tubes and etc.).
It is expected under the realization of the project to get the mass reflectron features not worse:
- mass range 1-150 а.е.м
- resolving power (on 10% level) not less than 200
- sensitivity (He) 10-8 Pa
- dynamic range 106-107
- time of registrations of 20 components less 1 s
- absence of an increasing of background of detector
- length of analyzer ~ 500 mm
- possibility of work in automatic mode
- possibility of accommodation in a glove box, while working with radioactive gasses.
Russia organizations, participating in the project (VNIINM, VNIITF, NIIEFA), have a significant experience (with the beginning of 80-h) and methodology in the field of development of mass-spectrometers for light gases and work with tritium mixtures. On initial stage it is expected discussion, adjustment (as required) and co-ordination with collaborators the following questions:
- statement of the problem, acquisition of extras, plan of work
- while performing the Project it is planned regularly discussions of main results and to conduct working counsels
- provided participation in joint tests
- publications of results
Interest in work has expressed General Atomic (USA). The need of development of small-dimensioned specialized mass spectrometer for tritium technological systems was stressed in discussions in KfK with Dr.Penzhorn and Dr.Glugla and on meeting within the framework of "Fifth Topical Meeting on Tritium Technology in fission, fusion and isotopic application" (1995, Italy) with Dr.Price (GB) and Dr.Engehnan (Italy). Development of analytical equipment is also part "Tritium R&D Programs" for design work Tririum Plant ITER (Fusion Technology, v. 28 (3), part I, 1995, 491-495).