| 研究課題/領域番号 |
15K13618
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| 研究機関 | 東京大学 |
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研究代表者 |
ウッドワード ジョナサン 東京大学, 総合文化研究科, 准教授 (80526054)
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| 研究期間 (年度) |
2015-04-01 – 2017-03-31
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| キーワード | TIRF microscopy / Spin dynamics / Magnetic Field / Radical Pair / RYDMR / SEMF |
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| 研究実績の概要 |
The primary research goal for the first year of the project was to design and construct a new kind of microscope arrangement. It was decided that rather than the combined lens reflector arrangement originally proposed, the use of a single objective of very high numerical aperture operating in combined direct and total internal reflection illumination was preferred, as such lenses are commercially available. The main challenge of this new arrangement was to allow the light from a diode laser, serving as a probe beam, to a) be focused on to the back focal plane of a high numerical aperture (>1.4) objective lens in a total internal reflection geometry in order to create an evanescent light field at the sample; b) be enclosed within an optical cavity in order to allow multiple passes of the beam through the objective, increasing the extent of light absorbed by transient radical species generated by a pump beam; c) be steered by optics in an arrangement that allows access to the pump beam through the centre of the objective lens; d) be delivered in an optical arrangement that can be easily modified to allow TIRF microscopy to be undertaken.
Some time was devoted to analysing the pros and cons of different optical arrangements until a an optimal candidate was selected. The instrument was then built as a 3D model to ensure that there were no resulting problems in mounting optics. After construction of the 3D model, all the various components needed for construction were then purchased and construction of the microscope commenced. Construction of the microscope is nearly complete.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
The project is running a little behind schedule for two primary reasons:
1) Based on restrictions on the dimensions of available optical mounts, building an optical arrangement using a commercial high numerical aperture objective proved a little more technically challenging than anticipated due to restraints on space to mount the optics. Finally, a working solution to the problem was developed. No equipment was ordered until this issue had been resolved, which meant that the apparatus was largely ordered later than anticipated.
2)Human resources in the Woodward group were substantially less than anticipated during the 2015-2016 financial year (the student allocated to work on this project decided to withdraw their application). This meant that the work had to be undertaken directly by the PI and a student busy on another project. This also resulted in slower progress than anticipated.
Despite the setbacks highlighted above, designs for the instrument were completed, components specified and ordered and construction of the microscope undertaken. It is anticipated that more rapid progress will be possible in the second year of the project.
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| 今後の研究の推進方策 |
Once the construction of the microscope is completed, experiments will be performed using camera based detection in TIRF mode to ensure correct operation. Once confirmed, the light sources will be reconfigured and the cavity mirrors installed to test the microscope in cavity based optical absorption mode, using a 50% modulated pump beam. Optimisation and testing will then take place and the performance of the microscope will be evaluated and results written up for publication in an instrumental journal as appropriate.
Subsequent work will largely follow the sequence highlighted in the original proposal. In TIRF mode, detection using sample scanning and single photon counting will be undertaken and the potential of making single molecule MFE measurements evaluated. If successful, measurements of single molecules of flavin adenine dinucleotide embedded in thin films will be investigated in detail.
In the final stages of the project, rapid switched magnetic field measurements and low field RYDMR measurements will also be undertaken in the TIRF arrangement where time allows.
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| 次年度使用額が生じた理由 |
The funds for the first year of the project were primarily for purchasing the components needed to construct the microscope. As the construction is not quite complete, a small amount of funds were held over for the purchase of additional optical elements / mounts in the final instrument configuration.
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| 次年度使用額の使用計画 |
The remaining funds will be used to purchase any necessary optical elements / mounts using the final stages of construction of the microscope and during testing and optimisation.
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