Section 47-8-20 - Membership in the fund; effect of contributions on eligibility for benefits and participation in the fund; payment of contributions for service rendered before becoming a member(a) All judges of the superior courts of this state who qualify under this chapter shall be eligible to participate in the fund. In order to be eligible to receive the benefits provided by this chapter, a judge of the superior court must begin making the contributions required by this chapter by December 31, 1964, or within 90 days after taking office as judge of the superior court, whichever date is later. Any judge who fails to begin making the contributions required by this chapter within the time required by this Code section shall be forever barred from participating in the fund.(b) Any judge of a superior court who desires to qualify under this chapter to participate in the fund shall, as a prerequisite to such participation, pay into the fund a sum of money equal to the contributions required by this chapter from the date of the beginning of his service as judge of a superior court until the date such sum of money is paid into the fund. At the same time he shall pay into the fund an amount of money equivalent to 6 percent simple interest on such sum of money for each year from the beginning of his service as a judge of a superior court until the date the contributions are paid into the fund.