Status of the TRIμP project

Abstract

At KVI the technical structures for the TRIμP facility are nearly all in place. The aim of the project is to use radioactive ions to study fundamental interactions and symmetries. We will measure β-recoil correlations in nuclear β decay. There the V,A structure of the Weak interaction may be violated. The second line of research is the search for a permanent electric dipole moment in Ra, with a magnitude forbidden by the Standard Model. By trapping these radioactive nuclei in atom traps a pure sample that can be manipulated facilitates these searches. The TRIμP facility consists of a production target and magnetic separator on the high energy side and a Radio-Frequency Quadrupole (RFQ) cooler and buncher on the low energy side. An ion catcher stops the fast product nuclides and transport them into the RFQ cooler. New technological approaches were implemented for several of these devices.

The Beta-Neutrino Correlation in Sodium-21 and Other Nuclei

“…The vertical grey band is allowed by the limit on the Fierz term from superallowed (0 + → 0 + ) Fermi decays [12]. The systems are 6 He [13] (blue), neutron [14] (pink) and [15] (orange), 21 Na (this work, red), 38m K [4] (green), and 32 Ar [16] (violet). A measurement for 23 Ne [17] is not shown, but is used to calculate the allowed region.…”

“…This would be particularly interesting in the case of 6 He, which has been discussed as a candidate for experiments in several forums, because of its pure Gamow-Teller transition, which cleanly constrains tensor couplings. The decay of 18 Ne would offer an opportunity to measure both pure Fermi and pure Gamow-Teller beta decays in the same nucleus, if the excited state is tagged in the detection.…”

“…Short-lived isotopes in neutral atom traps are an appealing source for the study of ! decay correlations, and many experiments have been performed and proposed in such systems [4][5][6]. Ideally, recoiling daughter nuclei and !…”

Atomic physics techniques for studying nuclear ground state properties, fundamental interactions and symmetries: status and perspectives

“…Strong enhancement is expected in the octupole-deformed region of radon or radium nuclei due to close-lying parity doublets. Experiments are planned by the groups at Argonne [246] and at KVI on 225 Ra in a magneto-optical trap [252] and by Chupp/Michigan on 223 Rn at TRIUMF in a cell [253]. Other systems might be even more favorable: Due to the Schiff moment, the expected EDM for 229 Pa is 3 · 10 4 larger than that of 199 Hg and 40 times larger than the 225 Ra moment [254].…”

“…The superconducting cyclotron AGOR at KVI Groningen is now mainly used for the TRIμP program [252,282]. Duurt Johan van der Hoek presented the facility in his talk on trapping of 21 Na.…”