Title:
マイクロ波誘導プラズマ用プラズマトーチ
Document Type and Number:
Japanese Patent JP2005526258
Kind Code:
A
Abstract:
A Plasma torch ( 10 ) for microwave induced plasma spectrochemical analysis of a sample includes a nozzle ( 30 ) in an inlet ( 18 ) for the main plasma gas flow between outer tube ( 12 ) and intermediate tube ( 14 ) of the torch ( 10 ). The nozzle ( 30 ) increases the gas flow velocity in the sheathing gas layer for the plasma which is provided by the gas flow from the annular gap ( 22 ) between the tubes ( 12 and 14 ). The increased velocity of the gas in the sheathing gas layer "stiffens" that layer and thus better confines the microwave induced plasma (such better confinement not being necessary for an ICP torch). Thus the torch is of improved durability for a microwave induced plasma compared to an ICP torch. The sample injection (inner) tube ( 16 ) may have a reduced diameter outlet at its end ( 34 ) which is substantially level with the end ( 35 ) of intermediate tube ( 14 ) to improve injection of a sample into the microwave induced plasma. The inlet end ( 26 ) of the sample injection tube ( 16 ) may include a heater ( 36 ) to assist in preventing blockages in tube ( 16 ) near its outlet end.
Inventors:
Hummer, Michael, Ron
Application Number:
JP2004506325A
Publication Date:
September 02, 2005
Filing Date:
May 21, 2003
Export Citation:
Assignee:
Varian Australia Pty.
International Classes:
G01N21/73; G01N22/00; H05H1/24; H05H1/30; G01N33/18; (IPC1-7): G01N21/73; H05H1/30
Attorney, Agent or Firm:
Inaoka cultivation
Mio Kawasaki
Mio Kawasaki