The AC Stark frequency shift induced by blackbody radiation (BBR) is presently a limiting factor toward the accuracy evaluation of Cs fountain frequency standards [1] [2]. In fact, at laboratory temperature, the AC Stark relative frequency shift is of the order of 10-14 and therefore the black-body coefficient must be evaluated to the percent level if an accuracy below 10-15 is desired. The BIPM recommended coefficient is -1.69(4) · 10-14 for Cs atoms while recent BBR shift measurements performed at IEN (now INRIM) [3] [4] yield a value which differs by 18% from the accepted value. The Politecnico di Torino is now developing a new method for the measurement for the BBR shift, with the aim of resolving the discrepancy on the coefficient. In this paper the Politecnico di Torino method is analyzed with a full description of the new apparatus. The method is based on rapidly varying thermal cycles.

A New Proposal for the Measurement of blackbody Radiation Shift in a Cesium Fountain (The Politecnico di Torino Method) / Costanzo, Giovanni Antonio; Berutto, Marco; Caldera, M; DE MARCHI, Andrea. - STAMPA. - -:(2006), pp. 197-199. (Intervento presentato al convegno Frequency and Time Forum (EFTF), 2006 20th European tenutosi a Braunschweig nel 27-30 March 2006).

A New Proposal for the Measurement of blackbody Radiation Shift in a Cesium Fountain (The Politecnico di Torino Method)

COSTANZO, Giovanni Antonio;BERUTTO, Marco;DE MARCHI, ANDREA
2006

Abstract

The AC Stark frequency shift induced by blackbody radiation (BBR) is presently a limiting factor toward the accuracy evaluation of Cs fountain frequency standards [1] [2]. In fact, at laboratory temperature, the AC Stark relative frequency shift is of the order of 10-14 and therefore the black-body coefficient must be evaluated to the percent level if an accuracy below 10-15 is desired. The BIPM recommended coefficient is -1.69(4) · 10-14 for Cs atoms while recent BBR shift measurements performed at IEN (now INRIM) [3] [4] yield a value which differs by 18% from the accepted value. The Politecnico di Torino is now developing a new method for the measurement for the BBR shift, with the aim of resolving the discrepancy on the coefficient. In this paper the Politecnico di Torino method is analyzed with a full description of the new apparatus. The method is based on rapidly varying thermal cycles.
2006
9781467326421
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/1534713
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