Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 廖雪兒 | en_US |
dc.contributor.author | Liu, Suet-Yi | en_US |
dc.contributor.author | 李遠鵬 | en_US |
dc.contributor.author | 鈴木俊法 | en_US |
dc.contributor.author | Lee, Yuan-Pern | en_US |
dc.contributor.author | Suzuki, Toshinori | en_US |
dc.date.accessioned | 2014-12-12T01:25:28Z | - |
dc.date.available | 2014-12-12T01:25:28Z | - |
dc.date.issued | 2010 | en_US |
dc.identifier.uri | http://140.113.39.130/cdrfb3/record/nctu/#GT079525807 | en_US |
dc.identifier.uri | http://hdl.handle.net/11536/41242 | - |
dc.description.abstract | I have constructed a He(I) ultraviolet photoelectron spectrometer using a supersonic molecular beam and a two-dimensional position-sensitive detector of photoelectrons. The photoelectron imaging (PEI) spectrometer enabled measurements of photoelectron spectra and photoelectron angular distributions with an efficiency considerably higher than a conventional spectrometer using a hemispherical energy analyzer. The most crucial factor for this achievement was to overcome high susceptibility of PEI to background electrons generated by scattered He(I) radiation. I examined various designs of electrodes experimentally and computationally and identified the main source of the background photoemission as the repeller plate used for acceleration of electrons. I designed a new electrostatic lens that intercepts background photoelectrons from the repeller plate traveling toward the imaging detector. High energy resolution (□E/E) of 0.735 % was achieved at E = 5.461 eV with He(I) radiation that has rather poor beam characteristics. The photoelectron angular anisotropies as a function of photoelectron kinetic energies are presented for jet-cooled benzene and pyridine. The PEI spectrometer was also employed in photoionization experiments using a vacuum ultraviolet free electron laser (VUV-FEL) at SPring-8 in Japan as a light source. A time-resolved photoelectron imaging using a femtosecond ultraviolet (UV) laser as a pump pulse and the VUV-FEL as a probe pulse is presented. Ultrafast internal conversion and intersystem crossing in pyrazine in a supersonic molecular beam were clearly observed. The VUV radiation allowed us to observe the entire Franck-Condon envelope in photoionization from a transient electronic state, which was not possible in UV-DUV experiment in the laboratory. | zh_TW |
dc.description.abstract | I have constructed a He(I) ultraviolet photoelectron spectrometer using a supersonic molecular beam and a two-dimensional position-sensitive detector of photoelectrons. The photoelectron imaging (PEI) spectrometer enabled measurements of photoelectron spectra and photoelectron angular distributions with an efficiency considerably higher than a conventional spectrometer using a hemispherical energy analyzer. The most crucial factor for this achievement was to overcome high susceptibility of PEI to background electrons generated by scattered He(I) radiation. I examined various designs of electrodes experimentally and computationally and identified the main source of the background photoemission as the repeller plate used for acceleration of electrons. I designed a new electrostatic lens that intercepts background photoelectrons from the repeller plate traveling toward the imaging detector. High energy resolution (□E/E) of 0.735 % was achieved at E = 5.461 eV with He(I) radiation that has rather poor beam characteristics. The photoelectron angular anisotropies as a function of photoelectron kinetic energies are presented for jet-cooled benzene and pyridine. The PEI spectrometer was also employed in photoionization experiments using a vacuum ultraviolet free electron laser (VUV-FEL) at SPring-8 in Japan as a light source. A time-resolved photoelectron imaging using a femtosecond ultraviolet (UV) laser as a pump pulse and the VUV-FEL as a probe pulse is presented. Ultrafast internal conversion and intersystem crossing in pyrazine in a supersonic molecular beam were clearly observed. The VUV radiation allowed us to observe the entire Franck-Condon envelope in photoionization from a transient electronic state, which was not possible in UV-DUV experiment in the laboratory. | en_US |
dc.language.iso | en_US | en_US |
dc.subject | 電子影像 | zh_TW |
dc.subject | He(I) | en_US |
dc.subject | photoelectron imaging | en_US |
dc.title | 分子束多原子分子之紫外光光電子影像 | zh_TW |
dc.title | Vacuum ultraviolet photoelectron imaging of polyatomic molecules in supersonic molecular beams | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | 應用化學系碩博士班 | zh_TW |
Appears in Collections: | Thesis |
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