Title : 
NIST-7, the new US primary frequency standard
         
        
            Author : 
Drullinger, R.E. ; Lowe, J.P. ; Glaze, D.J. ; Shirley, Jon
         
        
            Author_Institution : 
Nat. Inst. of Stand. & Technol., Boulder, CO, USA
         
        
        
        
        
        
            Abstract : 
NIST-7, an optically pumped, cesium-beam frequency standard, has replaced NBS-6 as the official US primary frequency standard. The present short-term stability of the standard, measured with respect to an active hydrogen maser, is characterized by σ/t(τ) ≈88 × 10-13 τ-1/2/. A first evaluation has resulted in an uncertainty of 4 × 10-14. An improved servo-electronic system is being developed which should improve stability and allow more precise evaluation of the various systematic errors
         
        
            Keywords : 
atomic clocks; frequency measurement; frequency stability; measurement standards; NBS-6; NIST-7; US primary frequency standard; active H maser; optically pumped Cs beam frequency standard; servo-electronic system; short-term stability; systematic errors; Atom optics; Atomic beams; Frequency conversion; Hydrogen; Masers; NIST; Optical frequency conversion; Optical polarization; Optical pumping; Stability;
         
        
        
        
            Conference_Titel : 
Frequency Control Symposium, 1993. 47th., Proceedings of the 1993 IEEE International
         
        
            Conference_Location : 
Salt Lake City, UT
         
        
            Print_ISBN : 
0-7803-0905-7
         
        
        
            DOI : 
10.1109/FREQ.1993.367379