Section 24. (a) A retired chief justice or associate justice of the supreme judicial court whose name has been placed on the list of retired justices pursuant to section sixty-five E of chapter thirty-two may be designated and assigned by the chief justice of the supreme judicial court to perform, during his term of eligibility, such of the duties of the office of associate justice of the supreme judicial court as may be requested of him and which he is willing to undertake, provided that no single assignment shall be for a term longer than ninety days, and provided that full-bench duties may be assigned only to fill a temporary vacancy, including temporary disability, on the court. Such retired chief justice or associate justice may also be designated and assigned by the chief justice of the supreme judicial court to perform; during his term of eligibility, such of the duties of judge of any lower court as may be requested of him and which he is willing to undertake provided that no single assignment shall be for a term of no longer than ninety days.

(b) In performing the service requested of him a retired chief justice or associate justice shall exercise all judicial powers and authority pertaining to the office in which he acts, with respect to matters as to which he is designated to act, and the fact of such service shall be stated on the records of the court, but need not be separately stated in the record or docket of any particular cause or proceeding. Service under the provisions of this section shall not be counted in determining the number of offices authorized or required by any applicable statute for the court on which a retired chief justice or associate justice might serve pursuant to this chapter.

(c) A retired chief justice or associate justice so serving shall be paid by the commonwealth, in addition to the pension or retirement allowance received, a per diem differential rate of compensation equivalent to one two hundred twentieths of the balance remaining after deducting the annual pension or retirement allowance received from the current annual salary of such justice if not retired. The per diem differential rate of compensation shall be paid monthly from Judiciary appropriated funds.

Such retired justice shall be entitled to all other benefits of a regular incumbent of the supreme judicial court and shall be reimbursed for expenses incurred while performing such services at any place other than his place of residence. While so serving he shall be entitled to receive such staff support, clerical assistance and facilities as are customarily available to judges of the court on which he serves.