Production and Spectroscopic Measurement of Dust Plasma in Superfluid Liquid Helium

超流液氦中尘埃等离子体的产生及光谱测量

• 批准号: 14580514
• 负责人: MINAMI Kazuo
• 金额: $ 2.3万
• 依托单位: NIIGATA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580514/
• 关键词: Liquid Helium; Dusty Plasma; Pulsed Discharge; Stark Broadening; Impurity Injection; Spectroscopy; Magnesium; Needle Electrodes; シュタルク幅; 分光スペクトル

Spectroscopic measurement of dusty plasma produced by high voltage pulsed discharge in superfluid liquid helium(LHe) is carried out. First, we tried to dissolve powder of silver(Ag) fine particle with diameter 0.07μm into LHe. Evaporation of LHe is enhanced by the fine particles, and they have tendency to adhere the wall of Dewar bottle which prevents optical observation. Next, we tried various metal rods as an electrode to initiate high voltage pulsed discharge that is ablated into LHe. So far, we are successful only to ablate magnesium(Mg) particles into LHe from the solid electrode. Tungsten(W) electrode with and Mg rod with 1mm diameter are fixed along a common axis at the bottom of the Dewar bottle filled with superfluid LHe. The light intensity of collimated image of the source is introduced into optical spectrometer and time-resolved spectral line intensities produced dusty plasma are measured by multi-channel image intensifier(Hamamatsu, PMA-50). Spectral intensities of the light between the electrodes in 1 atmosphere helium gas at room temperature are measured. MgI line intensity at 518.2nm shows that the intensities are fifteen times stronger and light lasts for longer time for the case of that Mg rod is cathode rather than the case that the polarity is opposite. Then, the electrodes are immersed in LHe with the former polarity. During the pulsed discharge, intense continuum lights and strong HeI triplet line at 587.6nm are observed that means the presence of high-density plasma. The light from the plasma is extinguished at 20μs after the pulsed discharge because of cooling effect of ambient LHe. On the other hand, MgI lines at 518.2 and 552.8nm can be observed until 35μs, after the helium plasma ends. Plasma of ablated Mg dusty particles is estimated to be produced in the LHe. The sizes of the localized dusty plasma are measured in some detail. The sizes of the dusty particle are remained to be examined in future.

在超级流体液氦（LHE）中进行尘埃式排放的光谱测量。 。时间分辨的光谱线紧张产生的尘土飞扬的血浆是通过数量通道年龄增强剂测量的（Hamamatsu，PMA-50）。情况是相反的。另一方面，在脉冲后，脉冲放电后，可以在518.2和552.8nm处进行MGI线，以在LHE中产生将来可以对其进行检查。

项目成果

C.Kojima, K.Minami 他2名: "Optical Observation of Localized Plasma after Pulsed Discharges in Liquid Helium"IEEE Trans.on Plasma Science. 31. 1379-1383 (2003)

C.Kojima、K.Minami 和其他 2 人：“液氦脉冲放电后局部等离子体的光学观察”IEEE Trans.on Plasma Science 31. 1379-1383 (2003)。

K.Minami, Y.Yamanishi, C.Kojima, M.Shindo, O.Ishihara: "Very Slowly Decaying Afterglow Plasma in Cryogenic Helium Gas"IEEE Trans. Plasma Science. 31・3(発表予定). (2003)

K.Minami、Y.Yamanishi、C.Kojima、M.Shindo、O.Ishihara：“低温氦气中的缓慢衰变余辉等离子体”IEEE Trans 31·3（即将发表）。

K.Minami 他4名: "Very Slowly Decaying Afterglow Plasma in Cryogenic Helium Gas"IEEE Trans.on Plasma Science. 31. 429-437 (2003)

K. Minami 和其他 4 人：“低温氦气中缓慢衰变的余辉等离子体”IEEE Trans.on Plasma Science 31. 429-437 (2003)。

C.Kojima, K.Minami他2名: "Optical Observation of Localized Plasma after Pulsed Discharges in Liquid Helium"IEEE Trans. on Plasma Science. 31(印刷中). (2003)

C. Kojima、K. Minami 和其他 2 人：“液氦中脉冲放电后的局部等离子体的光学观察”，IEEE Trans，等离子体科学 (2003 年)。

K.Miami他4名: "Very Slowly Decaying Afterglow Plasma in Cryogenic Helium Gas"IEEE Trans. on Plasma Science. 31. 429-437 (2003)

K. 迈阿密和其他 4 人：“低温氦气中缓慢衰变的余辉等离子体”IEEE Trans on Plasma Science 31. 429-437 (2003)。