Francium (Fr), which is the alkali atom in the 7th period, can be obtained as ultracold atoms with laser cooling and trapping techniques, and could be employed for the experiments on searches for the ...permanent electric dipole moment (EDM) of an electron. In order to improve the sensitivity of the electron EDM search, development of a high-intensity source of Fr atoms is essential. We demonstrated a production of a high intensity
210
Fr ion beam with a rate of
5
×
10
6
ions/s by a fusion reaction with bombardment of an accelerated
18
O beam onto a fixed gold target in RIKEN. The Fr products inside the gold target were extracted from the gold surface as an ion beam focused with an electrostatic field. We also discussed the method to produce
221
Fr by
α
-decay of
225
Ac. A neutron-rich
221
Fr isotope can be obtained as a daughter nucleus of this decay.
In Japan, research activities by junior and senior high school students show an upward trend. However, there are limited examples of research activities in the field of elementary particles and ...atoms. This is due to the difficulty associated with procuring research tools such as accelerators or particle detectors. Therefore, we hosted the 'Accel Kitchen' in 2018 and 2019 at the Cyclotron and Radioisotope Center (CYRIC) in Tohoku University where junior and senior high school students could participate in ongoing research of particle and atomic physics. At each workshop, 12 junior and senior high school students participated in the beam experiment, including the production of francium atoms (Fr) by the fusion reaction of oxygen and gold, optimizing the transport of the ion beam and identifying the alpha decay nuclei, and laser trapping of Fr for two days. Each group that was involved in the experiment was supported by researchers and university students who acted as mentors. This was the first opportunity for junior and senior high school students to know about the particle beam experiment in Japan.
We installed a 400-m-long polarization-maintaining fibers for magneto-optical trapping of Francium atoms. Fiber polarization stability of ∼9 × 10 -4 was achieved with an averaging time of 10 seconds, ...which even allows fluorescence observation at 20 atoms.
The TUCAN (TRIUMF Ultra-Cold Advanced Neutron) collaboration aims to search for the neutron electric dipole moment (nEDM) with unprecedented precision. One of the essential elements for the nEDM ...measurement is a polarization analyzer of ultracold neutrons (UCNs), whose main component is a magnetized thin iron film. Several thin iron films were deposited on aluminum and silicon ubstrates and were characterized by vibrating sample magnetometry and cold-neutron reflectometry. A magnetic field required to saturate the iron film is \(\sim\)12 kA/m for those on the aluminum substrates and 6.4 kA/m for the silicon substrates. The magnetic potential of the iron films on the Si substrate was estimated to be 2 T by the neutron reflectometry, which is sufficient performance for an UCN polarization analyzer of the nEDM measurement.
