Application of the electrostatic separation of recoil atoms to the²²⁵Ac-²²¹Fr-²¹⁷At-²¹³Bi decay series

Author

John Daniel Marsh

Date of Award

8-2000

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Chemistry

Major Professor

George K. Schweitzer

Committee Members

Joe Peterson, John Turner, Larry Miller, Saed Mirzadeh

Abstract

The focus of this research was to develop a novel approach for the separation of ²²¹Fr and ²¹³Bi from ²²⁵Ac. First a method was developed to electrodeposit the actinium onto a cathode from a pH = 2 nitric acid solution. Yields for the electrodeposition approached 99% for a one hour deposition. The Joliot Equation was used to quantitate the process. A linear velocity constant of 0.23 cm/min was measured for the electrodeposition of ²²⁵Ac on a Pt electrode. To separate the ²²¹Fr and ²¹³Bi, the atoms were caught in an electrostatic field as they recoiled from the cathode. The collection yield was found to be dependent on the electrostatic field strength with a critical voltage of about 2000 volts, above which the yield leveled off. The maximum yields for ²²¹Fr were found to occur after 40 minutes of collection. The yield for ²²¹Fr approached 50% while that for ²¹³Bi approached 99%. It was found that the activity of ²²¹Fr on the collector plate could be calculated by multiplying the chain decay equation by a geometry correction factor of the form: f= 0.5(1 - cosΘ) where Θ = tan^-1(R/d) and R = the radius of the collector and d is the distance between the plates. If secular equilibrium is assumed, then the equation reduces to simply: A_FR = A_Ac*f- The collection of the recoil atoms of ²²¹Fr and ²¹³Bi in an electrostatic field has been shown an effective and efficient means of their separation from ²²⁵Ac.

Recommended Citation

Marsh, John Daniel, "Application of the electrostatic separation of recoil atoms to the²²⁵Ac-²²¹Fr-²¹⁷At-²¹³Bi decay series. " PhD diss., University of Tennessee, 2000.
https://trace.tennessee.edu/utk_graddiss/8344