Plasma mass spectrometry
OwnerStephen E. Anderson, Ian L. Turnerinventors
Life of this patent
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Abstract
A plasma mass spectrometer has a plasma ion source (1). The source has associated with it an electromagnetic excitation means (2), which may be one or more induction coils. The excitation means is powered by an RF generator (3). Ions are sampled from the plasma ion source through an interface (15) into a vacuum chamber (16). The stream of ions is directed by an ion optics element (4) through a mass analyser (5) to an ion detector (6). The excitation means may include means (7) for altering the axial component of the electromagnetic field sustaining the plasma. Alternatively or additionally, the spectrometer may include signal detecting means (11,17) to provide feedback enabling optimisation of parameters.
Claims20
A plasma mass spectrometer comprising:
- (a) a plasma ion source having an electromagnetic excitation means associated therewith;
- (b) an alternating radio frequency (RF) power generator providing RF power to the excitation means;
- (c) an interface for sampling ions from the plasma into a vacuum chamber;
- (d) at least one ion optics element for directing a stream of ions from the interface;
- (e) a mass analyser and ion detector;
- and
- (f) means for altering the axial component of the electromagnetic field sustaining the plasma in response to a signal derived from a signal detecting means located intermediate said interface and said ion detector while the plasma is maintained.
A plasma mass spectrometer comprising:
- (a) a plasma ion source having an electromagnetic excitation means associated therewith;
- (b) an interface for sampling ions form the plasma into a vacuum chamber;
- (c) at least one ion optics element for directing a stream of ions from the interface;
- (d) a mass analyzer and ion detector;
- and
- (e) electromagnetic signal detecting means located upstream from the ion detector;
- wherein, in operation, the electromagnetic signal detecting means provides feedback information enabling the optimization of one or more parameters governing the maintenance of the plasma and location of the ion source.
A plasma mass spectrometer comprising:
- (a) a plasma ion source having an RF excitation means associated therewith;
- (b) an alternating RF power generator providing RF power to the excitation means;
- (c) an interface for sampling ions from said plasma into a vacuum chamber;
- (d) at least one ion optics element for directing a stream of ions from the interface;
- (e) a mass analyser and ion detector;
- (f) means for altering the axial component of the RF field sustaining the plasma while the plasma is operating;
- and
- (g) RF signal detecting means in said vacuum chamber upstream from the ion detector.
Dependencies are inferred from the claim text.