Emission Lines in 290–360 nm of Highly Charged Tungsten Ions W<sup>20+</sup>–W<sup>29+</sup>
Forbidden transitions in the near-UV and visible wavelength of highly charged tungsten (W) ions are potentially useful as novel tungsten diagnostics means of fusion plasmas. Emission lines in 290–360 nm from W<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-09-01
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| Series: | Atoms |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2218-2004/9/3/63 |
| Summary: | Forbidden transitions in the near-UV and visible wavelength of highly charged tungsten (W) ions are potentially useful as novel tungsten diagnostics means of fusion plasmas. Emission lines in 290–360 nm from W<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mi>q</mi><mo>+</mo></mrow></msup></semantics></math></inline-formula> ions interacting with an electron beam of 540–1370 eV are measured, using a compact electron-beam-ion-trap. The charge states of 64 lines are identified as W<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mn>20</mn><mo>+</mo></mrow></msup></semantics></math></inline-formula>–W<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mn>29</mn><mo>+</mo></mrow></msup></semantics></math></inline-formula>. A magnetic-dipole (M1) line of W<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mn>29</mn><mo>+</mo></mrow></msup></semantics></math></inline-formula> between the excited states <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mn>4</mn><msup><mi>d</mi><mn>8</mn></msup><mn>4</mn><mi>f</mi><mo>)</mo></mrow><mspace width="3.33333pt"></mspace><msub><mrow><mo>[</mo><msub><mrow><mo>(</mo><mn>4</mn><msubsup><mi>d</mi><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msubsup><mo>)</mo></mrow><mn>4</mn></msub><mspace width="3.33333pt"></mspace><mn>4</mn><msub><mi>f</mi><mrow><mn>7</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>]</mo></mrow><mrow><mn>13</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>→</mo><msub><mrow><mo>[</mo><msub><mrow><mo>(</mo><mn>4</mn><msubsup><mi>d</mi><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msubsup><mo>)</mo></mrow><mn>4</mn></msub><mspace width="3.33333pt"></mspace><mn>4</mn><msub><mi>f</mi><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>]</mo></mrow><mrow><mn>13</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></semantics></math></inline-formula> is newly identified; the wavelength is determined as 351.03(10) nm in air. The theoretical wavelength calculated using the multiconfiguration Dirac–Hartree–Fock method is in a good agreement with the measurement. |
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| ISSN: | 2218-2004 |