((a)) A person awarded a fellowship under the provisions of this subchapter shall continue to receive the payments provided in only during such periods as the Secretary of Energy finds that he is maintaining satisfactory proficiency in, and devoting essentially full time to, study or research in the field in which such fellowship was awarded, in an institution of higher education, and is not engaging in gainful employment other than part-time employment in teaching, research, or similar activities, approved by the Secretary of Energy.
((b)) The Secretary of Energy shall require reports containing such information in such forms and to be filed at such times as he determines necessary from each person awarded a fellowship under the provisions of this subchapter. Such reports shall be accompanied by a certificate from an appropriate official at the institution of higher education, library, archive, or other research center approved by the Secretary of Energy, stating that such person is making satisfactory progress in, and is devoting essentially full time to the research for which the fellowship was awarded.