Development of RIMS Apparatus for Isotope Analysis of Calcium in Nuclear Waste Materials

Abstract

We have developed a frequency stabilized laser system for RIMS analysis of a long-lived radionuclide of calcium ( 41 Ca) in concrete waste materials. A stable reference laser has been developed using magnetically induced circular dichroism of atomic rubidium. The frequency stability was estimated to be 50 kHz over 8-h period from beat frequency measurement. Furthermore, a computer-controlled fringe offset lock system has been developed to transfer the high frequency stability to the other lasers for three-step excitation of atomic calcium. By using the system precise frequency tuning of 1 MHz error over 1 GHz scan was realized. The overall frequency tuning precision was also confirmed by a multistep fluorescence and resonance ionization spectroscopy of calcium.

All-diode-laser cooling of Sr+isotope ions for analytical applications

“…We, therefore, introduced a digital fringe offset control (DFOC) system which realizes simultaneous frequency control of multiple lasers using a computer. 22) In this system, a stabilized He-Ne laser (Thorlabs HRS015) is used for the frequency reference. The cooling and repumping lasers frequency are controlled with respect to the He-Ne laser.…”

Development of Frequency Stabilized Diode Laser Based on a Spectroscopic Study of Magnetically Induced Circular Dichroism of Atomic Rubidium

“…Among them, a fringe-offset-lock (FOL) technique has been established for simultaneous stabilization of multiple tunable lasers. 1,2) In this technique, high frequency stability of the reference laser is transferred to the other lasers by a resonance cavity. For the reference laser, a commercial polarization-stabilized HeNe laser and an extended cavity diode laser (ECDL) stabilized by saturated absorption spectroscopy (SAS) or Pound-Drever-Hall (PDH) schemes are usually used.…”

“…Currently, we are developing a high-resolution multistep resonance ionization mass spectrometric (RIMS) apparatus for trace isotope analysis. 2,11) In this technique, several tunable lasers must be precisely and repeatedly tuned to various isotopic absorption lines by the FOL system; thus, the system requires a frequency-stabilized reference laser having a locking period of longer than several hours as well as a submegahertz stability. In this report, we present supplemental results to the previous studies on the DB-and DF-DAVLL techniques using the D 2 line of atomic Rb to reveal the applicability to long-term stabilization.…”