The 2015 Joint Conference of the IEEE International Frequency Control Symposium & European Frequency and Time Forum “IFCS-EFTF 2015” (http://ifcs-eftf2015.org/) will be held in Denver, Colorado, USA, April 12-16, 2015. This conference is is one of the leading international technical conferences for research, development, and applications of frequency control. Topics include, Materials, Filters, Resonators, MEMS, Oscillators, Synthesizers, Noise, Timekeeping, Optical and Microwave Atomic Standards, Sensors and Transducers. From Tabata Lab., 1 abstract was accepted by the technical program committee as Poster presentation. The authors and title is;
Authors: K. Ban, K. Tsujimoto*, Y. Hirai, A. Terao, N. Mizutani, T. Kobayashi, O. Tabata
Title: Alkali Metal Source Tablet for Vapor Cells of Atomic Magnetometers
Abstract
Toward practical implementation of optically pumped atomic magnetometers (OPAMs) using alkali metal vapor cell, the uniform quantity of potassium enclosed in the cells is required to suppress differences in atomic density and OPAM sensitivity. In order to make such vapor cells, we propose a novel method using potassium source tablet that feed fixed amounts of the potassium to the cells. This tablet consists of a porous alumina plate covered with a layer of KN3, and which was prepared by a simple two-step process: Droplets of KN3 aqueous solution were put onto a porous alumina substrate, and the water was then removed under vacuum. The yield of potassium was dependent on the pore size. The highest yield was 65% with an average pore size of 60 um. The sensitivity of 12 vapor cells operated as OPAMs was 3.3-3.8 fTrms/(Hz^0.5) at a frequency of 10 kHz, indicating small variation in the sensitivity.