2021 Fiscal Year Annual Research Report
Electron electric dipole moment search by using polarized ultracold molecule s
| Project/Area Number |
21H01113
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| Allocation Type | Single-year Grants |
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| Research Institution | Okayama University |
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Principal Investigator |
DOYLE JOHN 岡山大学, 異分野基礎科学研究所, 客員教授 (50870432)
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| Co-Investigator(Kenkyū-buntansha) |
吉村 浩司 岡山大学, 異分野基礎科学研究所, 教授 (50272464)
増田 孝彦 岡山大学, 異分野基礎科学研究所, 特任准教授 (90733543)
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| Project Period (FY) |
2021-04-01 – 2025-03-31
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| Keywords | electric dipole moment / buffer gas cooling / thorium oxide |
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| Outline of Annual Research Achievements |
As for the photodetector development, we have procured various items for mass production. For example, we procured photosensors (Silicon photomultiplier: SiPM) which are the most important part of the detector. We got relatively low-dark count individual sensors. Since suppressing the dark count is one of the crucial points in the development, we plan to cool the SiPMs below the dew point, the low-dark count individuals mitigate the cooling requirements of the detectors.
In order to mitigate stray light from the readout laser scattering, we procured 2 pieces of custom-made interference bandpass filters, which have a great extinction ratio between ~510nm (signal wavelength) and longer than 700 nm (background wavelength) for a prototype test. Based on the test, we confirmed that the stray light suppression ratio is high enough while keeping over 90% transmission for the signal wavelength.
We also prepared various peripheral hardware such as parts of preamplifier boards and assemblies, and vacuum feedthrough assemblies.
Mass production has already been launched in this period and will be finished probably at the beginning of the next fiscal year. We are also constructing operating software and hardware in parallel.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We had planned that the detector mass production will be launched this fiscal year, and we have started the mass production based on this grant at the Okayama site. The item procurement for the mass production has been almost done and assembly work is ongoing. We also almost finished the buffer gas beam source which the PI is responsible for at the Harvard site. All of this work aims for the full assembly of the apparatus at Northwestern University, which is scheduled for the first half of the next Japanese fiscal year.
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| Strategy for Future Research Activity |
The photodetector development is being finalized and we will integrate this subsystem into the entire apparatus in the first half of the next fiscal year. The co-researchers will go on-site (Northwestern University, U.S.A.) to integrate the photodetectors and associated equipment. They will travel there several times to integrate and operate the detectors and perform the experiment with the collaborators.
The PI will manage the entire project: finalizing the design of the experimental apparatus, especially the new buffer gas source and photo detection system.
We plan to launch the physics run this fiscal year after investigating possible systematic sources with the actual apparatus and data acquisition system.
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