Claims
- 1. A method for producing a directed gas jet, comprising the following steps:a) generating a guided sample gas beam b) generating an auxiliary gas beam which is directed and guided in the same direction as, but extends separately from, said sample gas beam, c) providing a pulsed carrier gas beam and combining it with said sample gas beam such that said sample gas is embedded in said carrier gas beam in axially spaced pulses which are axially compressed by said carrier gas, and combining said sample gas beam and said auxiliary gas beam over a certain distance.
- 2. A method according to claim 1, wherein also said auxiliary gas beam is pulsed.
- 3. A method according to claim 1, wherein, after said certain distance of combined gas flow, said combined gas flow is radially constricted.
- 4. A method according to claim 2, wherein said pulses are controlled so as to provide a correlation between the carrier gas pulses and the auxiliary gas pulse.
- 5. A method according to claim 3, wherein, after the radial constriction of said gas beam, the gas is expanded so as to be adiabatically cooled thereby.
- 6. A method according to claim 1, wherein said sample gas beam is constricted before its combination with the auxiliary gas beam.
- 7. A method according to claim 3, wherein said gas beam is constricted by Laval or Venturi nozzles.
- 8. A device for producing a directed gas jet from a sample gas beam embedded in an auxiliary gas beam, said device including a central sample gas guide tube, an auxiliary gas guide tube disposed concentrically around said central sample gas tube, said sample gas guide tube having an end with an opening disposed within said auxiliary gas guide tube, means for admitting a sample gas to said sample gas guide tube and means for admitting an auxiliary gas to said auxiliary gas guide tube and including a pulsed valve for controlling the admission of said auxiliary gas to the auxiliary gas guide tube.
- 9. A device according to claim 8, wherein said auxiliary gas guide tube has a constriction at its open end downstream of said auxiliary gas guide tube.
- 10. A device according to claim 8, wherein said means for admitting a sample gas to said sample gas guide tube includes a radial sample gas supply line and said sample gas guide tube includes, at its upstream end, a pulse valve for admitting carrier gas pulses to said sample gas guide tube for providing compressed sample gas pulses between said carrier gas pulses.
- 11. A device according to claim 10, wherein said pulse valves are controllable by a programmable control unit for controlling the timing correlation of the carrier gas pulses and the auxiliary gas pulses.
- 12. A device according to claim 8, wherein said sample gas guide tube has a constriction at its open end in said auxiliary gas guide tube.
- 13. A device according to claim 12, wherein said constrictions in said auxiliary gas guide tube and said sample gas guide tube are either one of a Laval and Venturi nozzle.
- 14. A device according to claim 8, wherein said device is a gas inlet structure of an ion source.
- 15. A device according to claim 8, wherein said device is a gas inlet structure of a fluorescence or absorption spectrometer.
- 16. A device according to claim 8, wherein said device is a gas inlet structure of a pulsed aerosol beam.
Priority Claims (1)
Number |
Date |
Country |
Kind |
198 22 672 |
May 1998 |
DE |
|
Parent Case Info
This is a continuation-in-part application of international application PCT/EP99/03419 filed May 18, 1999 and claiming the priority of German application 198 22 672.1 filed May 20, 1998.
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
4938256 |
Wiegleb et al. |
Jul 1990 |
A |
5311016 |
Villa-Aleman |
May 1994 |
A |
5345079 |
French et al. |
Sep 1994 |
A |
5536323 |
Kirlin et al. |
Jul 1996 |
A |
5742050 |
Amirav et al. |
Apr 1998 |
A |
Foreign Referenced Citations (2)
Number |
Date |
Country |
44 41 972 |
Aug 1996 |
DE |
0 770 870 |
May 1997 |
EP |
Non-Patent Literature Citations (1)
Entry |
Chung Hang Sin et al., “Supercritical Fluid/Supersonic Jet Spectroscopy with a Sheath-Flow Nozzle”, Analytical Chemistry, vol. 64, No. 2, Jan. 15, 1992pp. 233-238. |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
PCT/EP99/03419 |
May 1999 |
US |
Child |
09/722445 |
|
US |