Portable Plasma Source for Optical Spectroscopy

• US 20180238807A1
• Filed: 02/15/2018
• Published: 08/23/2018
• Est. Priority Date: 02/17/2017
• Status: Active Grant

• Current Assignee: Radom Corporation
• Original Assignee: Radom Corporation
• Inventors: Menon, Ashok, Pikelja, Velibor, Jevtic, Jovan
• Granted Patent: US 10,900,907 B2
• Time in Patent Office: Days
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/443 Emission spectrometry
• CPC Class Codes: G01N 21/73 using plasma burners or torches
• CPC Class Codes: G01N 2201/0221 Portable; cableless; compact; hand-held
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/32201 Generating means
• CPC Class Codes: H01J 37/32247 Resonators
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 49/0404 Capillaries used for transferring samples or ions electrospray nozzles H01J49/167
• CPC Class Codes: H01J 49/105 using high-frequency excitation, e.g. microwave excitation, Inductively Coupled Plasma [ICP]

Abstract

A portable, modular plasma source allows the production of an emission spectrometer by combination with a common portable fiber optic spectrograph by channeling emitted light through a fiber optic coupling communicating light from the plasma source to the portable fiber optic spectrograph.

Claims

1. A modular plasma source for plasma emission spectroscopy comprising:

a housing having a base on which the housing may be supported, the housing in turn supporting;

an electronically controllable plasma generator;

a sample-handling system for introducing a sample into plasma generated by the plasma generator;

an optical collimation system capturing light from the plasma heated sample; and

a fiber optic connector receiving collimated light from the optical collimation system and coupling that light to an optical fiber releasably attached to the fiber optic connector and adapted to communicate with an external portable spectrometer.

2. The modular plasma source of claim 1 wherein the plasma source has a weight of less than 50 pounds.

3. The modular plasma source of claim 2 wherein the housing has a lower horizontal surface adapted to be supported by a bench or the like and fitting within an area of less than four square feet.

4. The modular plasma source of claim 1 wherein the plasma generator provides an annular ring of dielectric material concentric about an axis and generating plasma along the axis.

5. The modular plasma source of claim 1 wherein the axis is a vertical orientation of the housing supported by the base.

6. The modular plasma source of claim 4 wherein the optical collimation system receives light along the axis.

7. The modular plasma source of claim 6 further including an air knife positioned along the axis between the annular ring dielectric and the optical collimation system.

8. The modular plasma source of claim 6 wherein the optical collimation system includes a mirror.

9. The modular plasma source of claim 8 wherein the mirror is an ultraviolet enhanced aluminum parabolic mirror.

10. The modular plasma source of claim 4 further including a power supply receiving line power and communicating with a microwave generator inductively coupled to the annular ring to excite the annular ring into resonance.

11. The modular plasma source of claim 1 wherein the housing includes a handle on the top of the housing opposite the base for lifting the housing by the use of the handle by an individual.

12. The modular plasma source of claim 1 further including inlet connectors attached to the housing for receiving argon and nitrogen to be conducted to the plasma generator.

13. The modular plasma source of claim 1 wherein the housing provides a horizontal bench positioned beneath an overhang portion, wherein the sample handling system is exposed for access between the bench portion and the overhang and wherein the overhang portion describes an internal volume holding the electronically controllable plasma generator and optical collimation system and having a connector for communicating with an exhaust duct.

14. The modular plasma source of claim 1 wherein the fiber optic connector is an SMA-905 optical connector.

15. The modular plasma source of claim 1 further including a portable fiber optic spectrometer having a sensitivity from 190-850 nanometers communicating via a fiber optic with the releasable fiber optic connector.