Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-C
Abstract Confinement time of electron plasmas trapped using a purely toroidal magnetic field has been found to exceed $${100}\, \hbox {s}$$ 100 s in a small aspect ratio ( $$R_{o}/a \sim {1.59}$$ R o / a ∼ 1.59 , $$R_o$$ R o and a are device major and minor radius, respectively), partial torus. It i...
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| Format: | Article |
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Nature Portfolio
2023-11-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-023-44849-2 |
| _version_ | 1797636899093872640 |
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| author | Lavkesh Lachhvani Sambaran Pahari Rajiv Goswami Yogesh G. Yeole Minsha Shah Nikhil Mohurle Prabal K. Chattopadhyay |
| author_facet | Lavkesh Lachhvani Sambaran Pahari Rajiv Goswami Yogesh G. Yeole Minsha Shah Nikhil Mohurle Prabal K. Chattopadhyay |
| author_sort | Lavkesh Lachhvani |
| collection | DOAJ |
| description | Abstract Confinement time of electron plasmas trapped using a purely toroidal magnetic field has been found to exceed $${100}\, \hbox {s}$$ 100 s in a small aspect ratio ( $$R_{o}/a \sim {1.59}$$ R o / a ∼ 1.59 , $$R_o$$ R o and a are device major and minor radius, respectively), partial torus. It improves upon the previously reported confinement time by nearly two orders of magnitude. Lifetime is estimated from the frequency scaling of the linear diocotron mode launched from sections of the wall, that are also used for mode diagnostics. Confinement improves as neutral pressures are reduced to $$< 5 \times 10^{-10} \hbox{mbar}$$ < 5 × 10 - 10 mbar in the presence of a steady state magnetic field of 200 Gauss ( $$\sim {60}\, \hbox {s}$$ ∼ 60 s with droop $$< 0.1\%$$ < 0.1 % ) at $${100}\, \hbox {V}$$ 100 V electron injection energies. With reduced pressures the role of (ion driven) instability diminishes and loss mechanisms resulting from elastic electron–neutral (e–n) and the ubiquitous electron–electron (e–e) scattering seem to play an important role which suggests low electron temperatures. The contribution to electron population resulting from the ionization of background neutral gas at these temperatures and pressures are expected to be insignificant and is corroborated in our experiments. |
| first_indexed | 2024-03-11T12:41:45Z |
| format | Article |
| id | doaj.art-701e18c17bd842d8918eeabe006f6599 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-03-11T12:41:45Z |
| publishDate | 2023-11-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-701e18c17bd842d8918eeabe006f65992023-11-05T12:17:29ZengNature PortfolioScientific Reports2045-23222023-11-011311810.1038/s41598-023-44849-2Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-CLavkesh Lachhvani0Sambaran Pahari1Rajiv Goswami2Yogesh G. Yeole3Minsha Shah4Nikhil Mohurle5Prabal K. Chattopadhyay6Institute for Plasma Research, A CI of Homi Bhabha National InstituteBhabha Atomic Research Centre, HBNIInstitute for Plasma Research, A CI of Homi Bhabha National InstituteInstitute for Plasma Research, A CI of Homi Bhabha National InstituteInstitute for Plasma Research, A CI of Homi Bhabha National InstituteInstitute for Plasma Research, A CI of Homi Bhabha National InstituteInstitute for Plasma Research, A CI of Homi Bhabha National InstituteAbstract Confinement time of electron plasmas trapped using a purely toroidal magnetic field has been found to exceed $${100}\, \hbox {s}$$ 100 s in a small aspect ratio ( $$R_{o}/a \sim {1.59}$$ R o / a ∼ 1.59 , $$R_o$$ R o and a are device major and minor radius, respectively), partial torus. It improves upon the previously reported confinement time by nearly two orders of magnitude. Lifetime is estimated from the frequency scaling of the linear diocotron mode launched from sections of the wall, that are also used for mode diagnostics. Confinement improves as neutral pressures are reduced to $$< 5 \times 10^{-10} \hbox{mbar}$$ < 5 × 10 - 10 mbar in the presence of a steady state magnetic field of 200 Gauss ( $$\sim {60}\, \hbox {s}$$ ∼ 60 s with droop $$< 0.1\%$$ < 0.1 % ) at $${100}\, \hbox {V}$$ 100 V electron injection energies. With reduced pressures the role of (ion driven) instability diminishes and loss mechanisms resulting from elastic electron–neutral (e–n) and the ubiquitous electron–electron (e–e) scattering seem to play an important role which suggests low electron temperatures. The contribution to electron population resulting from the ionization of background neutral gas at these temperatures and pressures are expected to be insignificant and is corroborated in our experiments.https://doi.org/10.1038/s41598-023-44849-2 |
| spellingShingle | Lavkesh Lachhvani Sambaran Pahari Rajiv Goswami Yogesh G. Yeole Minsha Shah Nikhil Mohurle Prabal K. Chattopadhyay Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-C Scientific Reports |
| title | Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-C |
| title_full | Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-C |
| title_fullStr | Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-C |
| title_full_unstemmed | Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-C |
| title_short | Unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in SMARTEX-C |
| title_sort | unprecedented confinement time of electron plasmas with a purely toroidal magnetic field in smartex c |
| url | https://doi.org/10.1038/s41598-023-44849-2 |
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