Charge-exchange spectroscopic diagnostics for neutral gas in electron beam ion trap

Liang Yaqiong; Liang Guiyun; Wei Huigang

doi:10.11884/HPLPB201830.180202

Volume 30 Issue 12

Dec. 2018

Turn off MathJax

Article Contents

Article Navigation > High Power Laser and Particle Beams > 2018 > 30(12): 122002

Liang Yaqiong, Liang Guiyun, Wei Huigang. Charge-exchange spectroscopic diagnostics for neutral gas in electron beam ion trap[J]. High Power Laser and Particle Beams, 2018, 30: 122002. doi: 10.11884/HPLPB201830.180202

Citation:

Liang Yaqiong, Liang Guiyun, Wei Huigang. Charge-exchange spectroscopic diagnostics for neutral gas in electron beam ion trap[J]. High Power Laser and Particle Beams, 2018, 30: 122002. doi: 10.11884/HPLPB201830.180202

Citation:

PDF( 3263 KB)

Charge-exchange spectroscopic diagnostics for neutral gas in electron beam ion trap

doi: 10.11884/HPLPB201830.180202

Liang Yaqiong^{1, 2
,},
Liang Guiyun^{2
,
,},
Wei Huigang²

1.
School of Logistics, Beijing Wuzi University, Beijing 101149, China
2.
National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China

Received Date: 2018-07-26
Rev Recd Date: 2018-11-06
Publish Date: 2018-12-15

Abstract

Abstract

Electron beam ion traps(EBITs) play an important role on extreme ultra-violet(EUV) and X-ray spectroscopy in laboratory astrophysics. Residual neutral gas in the EBIT trap center has a significant effect on ion breeding. In this work, we investigated the effect of residual neutral gas on the charge state distribution, as well as the diagnostic for the pressure in the trap center. The charge/energy exchange process between the neutral gas and highly charged ions not only affects the ionic fraction, but also plays an important role in fitting the excitation function (namely the relation curve of ionic fraction as a function of electron energies). By using the ionization equilibrium method on the measured excitation function, we have successfully estimated the residual neutral gas in the ion-electron interaction region of the trap center, as well as the vacuum pressure at the trap center.
- atomic processes,
- electron beam ion trap,
- extreme ultraviolet

FullText(HTML)

References(17)

References

[1]	Dere K P, Landi E, Mason H E, et al. CHIANTI—An atomic database for emission lines. Ⅰ. Wavelengths greater than 50 Å[J]. Astronomy and Astrophysics Supplement Series, 1997, 125(1): 149-173. doi: 10.1051/aas:1997368
[2]	Landi E, Young P R, Dere K P, et al. CHIANTI—An atomic database for emission lines. ⅩⅢ. Soft X-ray improvements and other changes[J]. The Astrophysical Journal, 2013, 763(2): 86. doi: 10.1088/0004-637X/763/2/86
[3]	Smith R K, Brickhouse N S, Liedahl D A, et al. Collisional plasma models with APEC/APED: emission-line diagnostics of hydrogen-like and helium-like ions[J]. The Astrophysical Journal Letters, 2001, 556(2): L91. doi: 10.1086/322992
[4]	Foster A R, Ji L, Smith R K, et al. Updated atomic data and calculations for X-ray spectroscopy[J]. The Astrophysical Journal, 2012, 756(2): 128. doi: 10.1088/0004-637X/756/2/128
[5]	Smith R K, Foster A R, Brickhouse N S. Approximating the X-ray spectrum emitted from astrophysical charge exchange[J]. Astronomische Nachrichten, 2012, 333(4): 301-304. doi: 10.1002/asna.201211673
[6]	Testa P, Drake J J, Landi E. Testing EUV/X-ray atomic data for the solar dynamics observatory[J]. The Astrophysical Journal, 2012, 745(2): 111. doi: 10.1088/0004-637X/745/2/111
[7]	Gillaspy J D, Lin T, Tedesco L, et al. Fe XVII X-ray line ratios for accurate astrophysical plasma diagnostics[J]. The Astrophysical Journal, 2011, 728(2): 132. doi: 10.1088/0004-637X/728/2/132
[8]	Bernitt S, Brown G V, Rudolph J K, et al. An unexpectedly low oscillator strength as the origin of the Fe XVII emission problem[J]. Nature, 2012, 492(7428): 225. doi: 10.1038/nature11627
[9]	Loch S D, Ballance C P, Li Y, et al. Non-equilibrium modeling of the Fe XVII 3C/3D line ratio in an intense X-ray free-electron laser excited plasma[J]. The Astrophysical Journal Letters, 2015, 801(1): L13. doi: 10.1088/2041-8205/801/1/L13
[10]	Liang G Y, Baumann T M, López-Urrutia J R C, et al. Extreme-ultraviolet spectroscopy of Fe Ⅵ-Fe ⅩⅤ and its diagnostic application for electron beam ion trap plasmas[J]. The Astrophysical Journal, 2009, 696(2): 2275. doi: 10.1088/0004-637X/696/2/2275
[11]	Liang G Y, López-Urrutia J R C, Baumann T M, et al. Experimental investigations of ion charge distributions, effective electron densities, and electron-ion cloud overlap in electron beam ion trap plasma using extreme-ultraviolet spectroscopy[J]. The Astrophysical Journal, 2009, 702(2): 838. doi: 10.1088/0004-637X/702/2/838
[12]	Gillaspy J D. Precision spectroscopy of trapped highly charged heavy elements: pushing the limits of theory and experiment[J]. Physica Scripta, 2014, 89: 114004. doi: 10.1088/0031-8949/89/11/114004
[13]	Liang G Y, Li F, Wang F L, et al. X-ray and EUV spectroscopy of various astrophysical and laboratory plasmas: Collisional, photoionization and charge-exchange plasmas[J]. The Astrophysical Journal, 2014, 783(2): 124. doi: 10.1088/0004-637X/783/2/124
[14]	Hahn M, Becker A, Bernhardt D, et al. Storage ring cross section measurements for electron impact single and double ionization of Fe¹³⁺ and single ionization of Fe¹⁶⁺ and Fe¹⁷⁺[J]. The Astrophysical Journal, 2013, 767(1): 47. doi: 10.1088/0004-637X/767/1/47
[15]	Dere K P. Ionization rate coefficients for the elements hydrogen through zinc[J]. Astronomy & Astrophysics, 2007, 466(2): 771-792.
[16]	Kim Y S, Pratt R H. Direct radiative recombination of electrons with atomic ions: Cross sections and rate coefficients[J]. Physical Review A, 1983, 27(6): 2913. doi: 10.1103/PhysRevA.27.2913
[17]	Epp S W, López-Urrutia J R C, Brenner G, et al. Soft X-ray laser spectroscopy on trapped highly charged ions at FLASH[J]. Physical review letters, 2007, 98(18): 183001. doi: 10.1103/PhysRevLett.98.183001