Asian Journal of Physics Vol 32, Nos 9 – 12 (2023) 627-636

Large volume plasma device-upgrade: A versatile plasma system for electron emitter, beam and wave based diagnostics

A K Sanyasi1, P K Srivastava1, Ayan Adhikari1,2, L M Awasthi1,2 and R Sugandhi1,2
1Institute for Plasma Research, Bhat, Gandhinagar-382 428, India
2Homi Bhaba National Institute, Training School Complex, Anushaktinagar, Mumbai- 400 094, India
Dedicated to Prof B N Basu

General classification of vacuum electronic devices are mostly based on their construction and operational principles, associated with generation of waves from low to ultrahigh frequencies comprising of amplifiers, oscillators, electron emitters, etc. The devices are further classified with regard to their operation by applying magnetic field or without magnetic field. Moreover, almost every plasma system requires a proper vacuum device with vacuum requirements typically between ~10–2 mbar to ~10–9 mbar. Such systems also require a primary electron source (emitter) to initiate the plasma either by field emission or by emission induced impact ionization. In this paper, we describe large volume plasma device-Upgrade (LVPD-U) as a system which produces plasmas with filamentary emission. The plasma is magnetized for electrons and un-magnetized for ions (AR+) with the scale lengths for electron (re) and ion (ri) Larmor radii and follows the order (re << ri, L), L being the system size. The LVPD-U is fancied with several diagnostics viz. electrical and magnetic probes, microwave interferometry, in-vacuum gridded electron beam source, visible spectrometry, RF-based quadruple mass analyzers and thyrotron based exciter for high frequency wave excitation, etc. The system is further being equipped with high-power electron cyclotron resonators and LASER system. The paper highlights on LVPD-U as a large vacuum plasma device and its various diagnostics, coupled to facilitate plasma diagnosis. © Anita Publications. All rights reserved.
Keywords: Vacuum, Plasma, Electron Gun, Microwave.

Peer Review Information
Method: Single- anonymous; Screened for Plagiarism? Yes
Buy this Article in Print © Anita Publications. All rights reserve


  1. Laframboise J G, Rubinstein J, Theory of a cylindrical probe in a collisionless magnetoplasma, Phys Fluids, 19 (1976)1900;
  2. Demidov V I, Ratynskaia S V, Rypdal K, Electric probes for plasmas: The link between theory and instrument, Rev Sci Instrum, 73(2002)3409–3439.
  3. Merlino R L, Understanding Langmuir probe current-voltage characteristics, Am J Phys, 75(2007)1078–1085.
  4. Sheehan P, Hershkowitz N, Emissive Probes, Plasma Sources Sci Technol, 20(2011)063001; org/ 10.1088/0963-0252/20/6/063001.
  5. Sanyasi A K, Srivastava P K, Awasthi L M, Plasma potential measurement using centre tapped emissive probe (CTEP) in laboratory plasma, Meas Sci Technol, 28(2017)045904;
  6. Everson T, Pribyl P, Constantin C G, Zylstra A, Schaeffer D, Kugland N L, Niemann C, Design, construction, and calibration of a three axis, high frequency magnetic probe (B-dot probe) as a diagnostics for exploding plasmas, Rev Sc Instrum, 80(2009)113505; doi: 10.1063/1.3246785.
  7. Banziger N U, Kammeyer M, Lange M, Plasma-density measurement by microwave interferometry and Langmuir probes in an rf discharge, Rev Sci Instrum, 64(1993)19–25.
  8. Lu Q, Wang S, Dou X, Electrostatic waves in an electron – beam plasma system, Phys Plasmas, 12(2005)072903;
  9. Leemans W, Esaray E, Laser-driven plasma-wave electron accelerators, Physics Today, 62(2009)44–49.
  10. Das P, Paikaray R, Samantaray S, Sethy B K, Sanyasi A K, Ghosh J, Determination of electron temperature of pulsed washer gun generated Argon plasma bu corona model, Fusion Sci Technol, 78(2022)56–65. 
  11. Sanyasi A K, Srivastava P K, Adhikari A, Awasthi L M, Leuva P, Santra P, Doshi B, Gupta M K, Sugandhi R, Large area multifilamentary plasma source for large volume plasma device- upgrade, Rev Sci Instrum, 93(2022)03546;
  12. Sanyasi A K, Sugandhi R, Srivastava P K, Srivastav P, Awasthi L M, Electro-mechanical probe positioning system for large volume plasma device, Rev Sci Instrum, 89(2018)055113;
  13. .Singh S K, Srivastava P K, Awasthi L M, Mattoo S K, Sanyasi A K, Singh R, Kaw P K, Performance of large electron energy filter in large volume plasma device, Rev Sci Instrum, 85(2014)033507;
  14. Sanyasi A K, Awasthi L M, Srivastava P K, Adhikari A, Sugandhi R, Real time measurement of AC and DC electron temperature using coupled center tap emissive and Langmuir probe (CCTELP), IPR internal report (IPR- RR-1472).