Modulation of Commercial Hollow Cathode Lamps by a Magnetic Field in a Magnetron Configuration

Abstract

An oscillating magnetic field generated by an underdamped capacitive discharge in a large coil is used to modulate the intensity of commercial hollow cathode lamps. Lamps are oriented in the coil so that the magnetic field is coaxial with the hollow cathode. This results in a pseudo-magnetron configuration where the magnetic field is normal to the electric field in the cathode space charge. This configuration results in ExB and diamagnetic drift motions of positive ions and electrons, so that these particles are trapped in circular orbits parallel to the cathode surface. Radiation intensity vs. time profiles are presented for Mn, Cr, Hg, Ag, and V lamps. With relatively high magnetic field strengths and low lamp current, periods of very low lamp intensity are obtained with high-intensity spikes occurring when the magnetic field changes direction. With lower field strengths and higher lamp current, a variety of patterns of intensity modulation is observed.

Keywords

Emission spectroscopy Plasma-magnetic field interaction Hollow-cathode excitation

Get full access to this article

View all access options for this article.

References

Marcus

R. K.

and Harrison

W. W.

, Anal. Chem. 58, 797 (1986).

Brackett

J. M.

and Vickers

T. J.

, Spectrochim. Acta 37B, 841 (1982).

Kruger

R. A.

Bombelka

R. M.

, and Laqua

, Spectrochim. Acta 35B, 581 (1980).

Harrison

W. W.

Hess

K. R.

Marcus

R. K.

, and King

F. L.

Jr. , Anal. Chem. 58, 341A (1986).

Savickas

P. J.

Hess

K. R.

Marcus

R. K.

, and Harrison

W. W.

, Anal. Chem. 56, 817 (1984).

Sacks

and Puig

, “Preliminary Characterization of A Hollow Cathode Lamp for Non-Metals Detection in GC Effluents,” delivered at the XIV Meeting of the Federation of Analytical Chemistry and Spectroscopy Societies, Detroit, Michigan (1987).

Tanguay

and Sacks

, Appl. Spectrosc. 42, (1988), accepted for publication.

Penfold

A. S.

and Thornton

J. A.

, U. S. Patent 4,041,353 (1977).

Arcidiacono

F. R.

, Proceedings of the 27th Electronic components Conference (IEEE, New York, 1977), p. 232.

10.

Green

F. A.

and Chapman

B. N.

, J. Vac. Sci. Technol. 13, 165 (1976).

11.

Thornton

J. A.

, J. Vac. Sci. Technol. 15, 171 (1978).

12.

Gill

W. D.

and Key

, Rev. Sci. Instrum. 36, 277 (1965).

13.

Wasa

and Hayakawa

, Proc. IEEE 55, 2179 (1967).

14.

Kirov

K. I.

Ivanov

N. A.

Atanasova

E. D.

, and Minchev

G. M.

, Vacuum 26, 237 (1976).

15.

Hosokawa

Tsukada

, and Misumi

, J. Vac. Sci. Technol. 14, 143 (1977).

16.

Arcidiacono

F. R.

, Proceedings of the 27th Electronic Components Conference (IEEE, New York, 1977), p. 232.

17.

Heisig

Goedicke

, and Schiller

, Proceedings of the 7th International Symposium on Electron Ion Beam Scientific Technology, Washington, D.C. (1976), p. 129.

18.

Chen

F. F.

, Introduction to Plasma Physics and Controlled Fusion (Plenum Press, New York, 1984), 2nd ed., Vol. 1.

19.

Thornton

J. A.

and Penfold

A. S.

, “Cylindrical Magnetron Sputtering,” in Thin Film Processes, Vossen

J. L.

and Cuomo

J. J.

, Eds. (Academic Press, New York, 1978).

20.

Sutton

C. W.

and Sherman

, Engineering Magnetohydrodynamics (McGraw-Hill, New York, 1965), p. 394.

21.

Trivedi

Tanguay

Matties

, and Sacks

, Appl. Spectrosc. 41, 833 (1987).

22.

Boyd

T. J. M.

and Sanderson

J. J.

, Plasma Dynamics (Barnes and Noble, New York, 1969).

23.

Kamla

G. J.

and Scheeline

, Anal. Chem. 58, 932 (1986).

24.

Kamla

G. J.

and Scheeline

, Anal. Chem. 58, 923 (1986).

25.

Duchane

D. V.

and Sacks

R. D.

, Anal. Chem. 50, 1752 (1978).

26.

Suh

S. Y.

Collins

R. J.

, and Sacks

R. D.

, Appl. Spectrosc. 35, 42 (1981).

27.

Glasstone

and Lovberg

, Controlled Thermonuclear Reactions (D. Van Nostrand Co., Princeton, New Jersey, 1960).

28.

Hayakawa

and Wasa

, Electr. Eng. in Jpn. 83, 36 (1963).

29.

Hayakawa

and Wasa

, J. Phys. Soc. Jpn. 20, 1692 (1965).