Federal offices are governed by the US Constitution, and there is no recall provision. US Senators can only be removed by the votes of their fellow Senators (for conviction of a crime, etc.)
Per the Congressional Research Service
http://www.senate.gov/CRSReports/crs-publish.cfm?pid=%270E%2C*PL[%3A%230%20%20%0A
From a Goldwater Guy........thank you for your research and information. It is sincerely & deeply appreciated.