本文選題：時(shí)間分辨激光誘導(dǎo)熒光 + 量子拍光譜��； 參考：《吉林大學(xué)》2016年博士論文

【摘要】：原子離子的結(jié)構(gòu)參數(shù)和輻射參數(shù)是原子物理學(xué)、分析化學(xué)、等離子體物理和天體物理學(xué)等學(xué)科領(lǐng)域研究所需的基礎(chǔ)數(shù)據(jù)。原子物理領(lǐng)域中,能級的自然輻射壽命和朗德因子是人們了解原子結(jié)構(gòu)、電子動(dòng)力學(xué)過程、角動(dòng)量耦合圖像和激發(fā)態(tài)原子輻射性質(zhì)的基本信息。天體物理學(xué)領(lǐng)域中,精確的振子強(qiáng)度等輻射參數(shù)在分析天體演化過程、確定化學(xué)元素豐度和了解恒星核合成過程等問題中亦有其重要作用。據(jù)文獻(xiàn)報(bào)道,稀土元素和鐵峰元素在化學(xué)特殊星、熾熱恒星等天體上有較高豐度,因此對其所屬元素輻射參數(shù)進(jìn)行研究與分析是很有必要的。本文利用時(shí)間分辨激光誘導(dǎo)熒光(TR-LIF)方法、量子拍光譜方法和激光燒蝕技術(shù),確定了鉻原子的朗德因子和自然輻射壽命,銩原子、銩一價(jià)離子和銪二價(jià)離子的自然輻射壽命。壽命測量過程中,用倍頻、三倍頻和受激拉曼散射等手段獲得可見及紫外波段的激發(fā)光;在真空室中,基態(tài)或亞穩(wěn)態(tài)的原子或離子被激發(fā)到目標(biāo)能級;由該能級向下自發(fā)輻射的熒光經(jīng)由聚焦透鏡、光柵單色儀和光電倍增管組成的探測系統(tǒng)進(jìn)行探測,然后傳輸?shù)绞静ㄆ髦酗@示并記錄;最后對熒光衰減曲線進(jìn)行e指數(shù)或解卷積擬合,確定能級的自然輻射壽命。合理地選擇磁場大小和適當(dāng)?shù)卣{(diào)節(jié)偏振方向,熒光信號出現(xiàn)振蕩,即產(chǎn)生量子拍衰減信號。然后對量子拍曲線進(jìn)行傅立葉變換得到量子拍頻,進(jìn)而確定能級的朗德因子。在實(shí)驗(yàn)過程中,通過使用不同的激發(fā)方案,改變觀測通道和延遲時(shí)間等方法,排除共激發(fā)的干擾,確保目標(biāo)能級被準(zhǔn)確激發(fā)。通過調(diào)節(jié)各種實(shí)驗(yàn)條件(如:激發(fā)和燒蝕光能量、燒蝕激光焦點(diǎn)大小、磁場強(qiáng)度和激發(fā)-燒蝕光之間的延遲時(shí)間等),消除各種物理效應(yīng)(如輻射陷阱效應(yīng)、超輻射效應(yīng)、量子拍效應(yīng)、飽和效應(yīng)、碰撞效應(yīng)和飛出視場效應(yīng)等)可能對壽命測量產(chǎn)生的影響。壽命結(jié)合分支比是一種確定躍遷幾率和振子強(qiáng)度的可靠方法。分支比測量方面,以空心陰極燈作為原子或離子譜線的發(fā)射源,由高分辨率光柵光譜儀測量發(fā)射譜,然后對躍遷譜線進(jìn)行擬合分析,用譜線的強(qiáng)度比來確定躍遷分支比。本論文具體內(nèi)容包括以下三個(gè)部分:一、運(yùn)用TR-LIF方法和和量子拍光譜方法,測量了Cr I 3d54p、3d44s4p、3d55p和3d44s5p組態(tài),能級位于23305.0026-53782.78 cm-1之間35條奇宇稱能級的朗德因子和43條奇宇稱能級的壽命。其中15個(gè)朗德因子和17個(gè)能級壽命屬于首次測量。測得的壽命值在11.4-193 ns范圍之間。把實(shí)驗(yàn)測量g因子值與不同純耦合方式下的g值進(jìn)行對比,發(fā)現(xiàn)所研究能級的耦合方式更接近LS耦合。此外,利用鉻空心陰極燈的原子發(fā)射譜,確定了8條鉻原子躍遷的分支比,并結(jié)合壽命數(shù)據(jù)確定了31條譜線的躍遷幾率和振子強(qiáng)度。二、運(yùn)用TR-LIF方法,測量了Tm I的4f125d6s6p、4f126s26p、4f136s8s、4f125d6s2、4f136s6p、4f136s7p、4f135d6p、和4f136s8p組態(tài)位于22791.176到48547.98cm-1之間88個(gè)激發(fā)態(tài)能級的自然輻射壽命,壽命值分布在15.4-7900 ns之間,其中77個(gè)能級屬于首次研究報(bào)道。還測量了Tm II的4f126s6p、4f125d6p、4f125d6s、4f125d2和4f126s2組態(tài)位于27294.79到65612.85 cm-1之間29個(gè)能級的自然輻射壽命,壽命值分布在36.5-1000 ns之間,其中22個(gè)能級屬于首次報(bào)到。另外,對15個(gè)Tm II能級的位置進(jìn)行了修正。三、利用TR-LIF方法,測量了Eu III 4f 6(7F)5d組態(tài)位于39636.83到42530.91cm-1之間6條偶宇稱能級的自然輻射壽命,其中3條能級屬于首次測量。它們的壽命值在33-130 ns之間,壽命誤差都在10%以內(nèi)。綜上所述,本文對鉻原子(Cr I)能級的自然輻射壽命、朗德因子和躍遷分支比進(jìn)行了測量研究,并確定了分支比測量譜線的振子強(qiáng)度;另外,還測量研究了銩原子(Tm I)、銩一價(jià)離子(Tm II)和銪二價(jià)離子(Eu III)能級的自然輻射壽命,得到了一批文獻(xiàn)中未見報(bào)道的新的原子輻射和朗德因子參數(shù)。這些原子數(shù)據(jù)不僅為確定天體中化學(xué)元素豐度提供豐富的光譜分析數(shù)據(jù),還對核聚變物理、原子物理和等離子體物理等領(lǐng)域相關(guān)問題的研究具有重要的科學(xué)價(jià)值。
[Abstract]:The structural parameters and radiation parameters of atomic ions are the basic data needed in the field of atomic physics, analytical chemistry, plasma physics and astrophysics. In the field of atomic physics, the natural radiation life of the energy level and the Lund factor are the understanding of the atomic structure, the electron dynamics process, the angular momentum coupling image and the excitation. The basic information of the properties of the atomic radiation. In astrophysics, the exact intensity of the vibrator and other radiation parameters also play an important role in the analysis of the evolution of the celestial bodies, the determination of the abundance of chemical elements and the understanding of the process of the synthesis of stars. With high abundance, it is necessary to study and analyze the radiation parameters of its elements. In this paper, a time resolved laser induced fluorescence (TR-LIF) method, a quantum beat spectrum method and a laser ablation technique have been used to determine the natural radiation life of the chromium atom and the natural radiation life, thulium, thulium and europium two valence ions. In the course of life measurement, the excitation of visible and ultraviolet bands is obtained by means of frequency doubling, three frequency doubling and stimulated Raman scattering; in the vacuum chamber, the atoms or ions of the ground state or metastable state are excited to the target level; the fluorescence of the spontaneous emission downward from the energy level is via the focusing lens, the grating monochromator and the photomultiplier group. The detection system is detected, then transmitted to the oscilloscope and displayed and recorded. Finally, the e exponent or deconvolution fitting is used to determine the natural radiation life of the energy level. The size of the magnetic field and the direction of polarization are properly adjusted. The fluorescence signal is oscillating, that is, the quantum beat attenuation signal is produced. Then, the quantum beat is produced. The curve is transformed by Fu Liye transform to obtain the quantum beat frequency and then determine the lad factor of the energy level. In the experiment, by using different excitation schemes, changing the observation channel and the delay time, eliminating the common excitation interference and ensuring the target energy level to be accurately excited. The effect of various physical effects (such as radiation trap effect, ultra radiation effect, quantum beat effect, saturation effect, collision effect, and flying out of view effect) on life measurement is eliminated. The life bound branching ratio is a kind of determination of transition probability and vibration. A reliable method of subdivision strength. In the aspect of branch ratio measurement, a hollow cathode lamp is used as the source of atomic or ion spectral lines. The emission spectrum is measured by a high resolution grating spectrometer. Then the transition spectrum is fitted and analyzed with the intensity ratio of the spectral line to determine the transition branch ratio. The specific contents of this paper include the following three parts: 1, using TR-LIF Methods and quantum beat spectroscopy, the Cr I 3d54p, 3d44s4p, 3d55p and 3d44s5p configurations are measured, and the lifetime of 35 odd parity energy levels and 43 odd parity energy levels between the energy levels are located between the 23305.0026-53782.78 cm-1 and the first measurements of 15 rad and 17 energy levels. The measured life values are in the 11.4-193 ns range. By comparing the g factor values with the g values in the different pure coupling methods, it is found that the coupling mode of the energy level is closer to the LS coupling. In addition, the branch ratio of the 8 chromium atom transition is determined by the atomic emission spectrum of the chromium hollow cathode lamp, and the transition probability and the oscillator strength of the 31 spectral lines are determined by the lifetime data. Two, The TR-LIF method is used to measure the natural radiation life of the 88 excited states of the 4f125d6s6p, 4f126s26p, 4f136s8s, 4f125d6s2,4f136s6p, 4f136s7p, 4f135d6p, and 4f136s8p configuration between 22791.176 and 48547.98cm-1, which are located between 22791.176 and 48547.98cm-1, and the lifetime values are between 15.4-7900. 26s6p, 4f125d6p, 4f125d6s, 4f125d2 and 4f126s2 configuration are located at the natural radiation life of 29 levels between 27294.79 and 65612.85 cm-1, the lifetime distribution is between 36.5-1000 ns, 22 of which belong to the first report. In addition, the position of the 15 Tm II levels is corrected. Three, the TR-LIF method is used to measure the configuration bits of the Eu 6. The natural radiation life of 6 parity energy levels between 39636.83 and 42530.91cm-1, of which 3 levels belong to the first measurement. Their life values are between 33-130 ns, and the lifetime error is within 10%. In summary, the natural radiation life of the chromium atom (Cr I), the Langde factor and the transition ratio are investigated and determined in this paper. In addition, the natural radiation life of thulium atom (Tm I), thulium monovalent ion (Tm II) and europium two valence ion (Eu III) energy level is also measured, and new atomic radiation and Lund factor parameters not reported in the literature are obtained. These atomic data are not only used to determine the abundance of chemical elements in the celestial bodies. It provides abundant spectral analysis data and has important scientific value for the research of nuclear fusion physics, atomic physics and plasma physics.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：O562

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本文編號：1964409