Skip to content

Research at St Andrews

Self-excitation and operational characteristics of the crossed-field secondary emission electron source

Research output: Contribution to journalArticle

Author(s)

Y M Saveliev, W Sibbett, D M Parkes

School/Research organisations

Abstract

We have investigated the crossed-field secondary emission (CFSE) electron source which is of a magnetron type with smooth cylindrical electrodes and axial applied magnetic field. It initiates at the negative slope d\U\/dt < 0 of the high voltage pulse U similar to 10-40 kV, but further current production is maintained by a self-sustained secondary electron emission regardless to the voltage pulse shape. The output electron beam is tubular with a thin similar to 1 mm wall. This article is concerned mainly with the identification of the mechanisms governing the excitation and generation of the electron beam and with the determination of the principles upon which the "optimal" CFSE electron source should be designed. We have demonstrated that the CFSE diode starts operation in a self-excitation regime (i.e., without application of the primary current) provided there is a partial trapping of the multiplying electrons inside the diode boundaries. The required axial decelerating force can be established with the use of either axial electric or nonuniform magnetic fields. Amongst all of the practical methods tested (shifting of the anode with respect to the cathode, double diode, diodes with ferromagnetic parts, use of the nonuniform external magnetic field), the diode with a ferromagnetic ring insert inside the cathode cylinder has been shown to be the most successful. It has generated an similar to 240 A electron beam with a perveance of similar to 85 mu A/V3/2. The operating range of the CFSE diode is limited by both low and high magnetic fields. The lower limit arises from a necessity to comply with a Hull cutoff condition. The upper limit is determined by the time required for development of an electron avalanche. A secondary electron emission mechanism of current production in the CFSE diode allows the diode to operate in an oscillating regime when the applied magnetic field is higher but close to the Hull cutoff value. It has thus been possible to generate 100% density modulated electron beams at a modulation frequency of similar to 10(7) Hz in our present experiments with the possibility of further increases up to similar to 10(8) Hz. A geometrical scaling law for the CFSE diodes has been deduced empirically. It states that the perveance of the output electron beam is proportional to the geometrical factor X = (D-k/d(e))(root L-d/d(e) - 0.8), where D-k is the cathode diameter, d(e) is an effective diode gap, and L-d is the diode length. The scaling law provides a tool for designing the CFSE diodes and predicting the ultimate beam currents. For a practical size of device, this electron current could be as high as similar to 1 kA. [S0034-6748(99)05012-1].

Close

Details

Original languageEnglish
Pages (from-to)4502-4514
Number of pages13
JournalReview of Scientific Instruments
Volume70
Publication statusPublished - Dec 1999

    Research areas

  • PLANAR, DIODES, YIELD, GAP

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. 3D laser nano-printing on fibre paves the way for super-focusing of multimode laser radiation

    Sokolovskii, G. S., Melissinaki, V., Fedorova, K. A., Dudelev, V., Losev, S. N., Bougrov, V. E., Sibbett, W., Farsari, M. & Rafailov, E. U., 2 Oct 2018, In : Scientific Reports. 8, 9 p., 14618.

    Research output: Contribution to journalArticle

  2. Ultrafast high-repetition-rate waveguide lasers

    Shepherd, D., Choudhary, A., Lagatsky, A. A., Kannan, P., Beecher, S., Eason, R., Mackenzie, J., Feng, X., Sibbett, W. & Brown, C. T. A., Mar 2016, In : IEEE Journal of Selected Topics in Quantum Electronics. 22, 2

    Research output: Contribution to journalArticle

  3. Dropout dynamics in pulsed quantum dot lasers due to mode jumping

    Sokolovskii, G. S., Viktorov, E. A., Abusaa, M., Danckaert, J., Dudelev, V. V., Kolykhalova, E. D., Soboleva, K. K., Deryagin, A. G., Novikov, I. I., Maximov, M. V., Zhukov, A. E., Ustinov, V. M., Kuchinskii, V. I., Sibbett, W., Rafailov, E. U. & Erneux, T., 29 Jun 2015, In : Applied Physics Letters. 106, 26, 5 p., 261103.

    Research output: Contribution to journalArticle

  4. Optical trapping with superfocused high-M2 laser diode beam

    Sokolovskii, G. S., Dudelev, V. V., Melissinaki, V., Losev, S. N., Sobolev, K. K., Deryagin, A. G., Kuchinskii, V. I., Farsari, M., Sibbett, W. & Rafailov, E. U., 3 Mar 2015, Laser Resonators, Microresonators, and Beam Control XVII. Kudryashov, AV., Paxton, AH., Ilchenko, VS., Aschke, L. & Washio, K. (eds.). Bellingham: SPIE, 7 p. (Proceedings of SPIE; vol. 9343).

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

  5. A diode-pumped 1.5 mu m waveguide laser mode-locked at 6.8 GHz by a quantum dot SESAM

    Choudhary, A., Lagatsky, A. A., Zhang, Z. Y., Zhou, K. J., Wang, Q., Hogg, R. A., Pradeesh, K., Rafailov, E. U., Sibbett, W., Brown, C. T. A. & Shepherd, D. P., Oct 2013, In : Laser Physics Letters. 10, 10, 4 p., 105803.

    Research output: Contribution to journalArticle

Related by journal

  1. Application of SQUIDs to low temperature and high magnetic field measurements—ultra low noise torque magnetometry

    Arnold, F., Naumann, M., Lühmann, T., Mackenzie, A. P. & Hassinger, E., Feb 2018, In : Review of Scientific Instruments. 89, 2, 8 p., 023901.

    Research output: Contribution to journalArticle

  2. Cryogenic STM in 3D vector magnetic fields realized through a rotatable insert

    Trainer, C. W. J., Yim, C. M., McLaren, M. & Wahl, P., Sep 2017, In : Review of Scientific Instruments. 88, 9, 4 p., 093705.

    Research output: Contribution to journalArticle

  3. Measurement of vacuum pressure with a magneto-optical trap: a pressure-rise method

    Moore, R., Lee, L., Findlay, E., Torralbo Campo, L., Bruce, G. D. & Cassettari, D., 15 Sep 2015, In : Review of Scientific Instruments. 86, 9, 093108.

    Research output: Contribution to journalArticle

  4. Piezoelectric-based apparatus for strain tuning

    Hicks, C. W., Barber, M. E., Edkins, S. D., Brodsky, D. O. & Mackenzie, A. P., 18 Jun 2014, In : Review of Scientific Instruments. 85, 6, 8 p., 065003.

    Research output: Contribution to journalArticle

  5. Construction and performance of a dilution-refrigerator based spectroscopic-imaging scanning tunneling microscope

    Singh, U. R., Enayat, M., White, S. C. & Wahl, P., 30 Jan 2013, In : Review of Scientific Instruments. 84, 1, 5 p., 013708.

    Research output: Contribution to journalArticle

Related by journal

  1. Review of Scientific Instruments (Journal)

    Graham David Bruce (Reviewer)
    2017 → …

    Activity: Publication peer-review and editorial work typesPeer review of manuscripts

ID: 833061

Top