Construction of an experiment providing cold strontium atoms for atomic interferometry in a ring cavity

• Autor(a) principal: Armijos, Michelle Alejandra Moreno
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/76/76132/tde-28052020-104753/
• topic: Armadilha magneto-óptica; Átomos frios; Cold atoms; Espectroscopia de absorção saturada; Estrôncio; Magneto-optical trap; Saturated absorption spectroscopy; Strontium

This thesis describes the first steps to fulfill the main objective of our project: the development of a gravimetry system based on the continuous monitoring of Bloch oscillations performed by ultra-cold strontium atoms. The realization of this project comprises three main stages: the first stage consists in obtaining a magneto-optical trap in the broad transition of 461 nm of strontium, the second stage is the transfer to a magneto-optical trap in the narrow intercombination line of 689 nm, and finally the third stage is the monitoring of Bloch oscillations of the cloud of atoms in a ring cavity. This work details the first stage of the project, the creation of an experimental apparatus which produces ultra-cold strontium atoms in the transition of 461 nm, as well as the characterization of the cloud of atoms, temperature, size, number of atoms, etc. For this project, a new experimental apparatus has been designed and realized. It involves an ultra-high vacuum system, magnetic field sources, laser systems and optical instruments which are required for cooling, trapping and repumping strontium atoms. A novel feature is the implementation of a transversely loaded two-dimensional magneto-optical trap, which serves as a source of a cold strontium atomic beam. A loading rate of the atomic beam into a nearby three-dimensional magneto-optical trap exceeding 105 s-1 for the 88Sr isotope at a moderate dispenser temperature of 600 °C are reported. The temperature of the cloud is about 4 mK and its size 0.3 mm, these characteristics suggest that the state of the atomic trap is in optimal conditions to make the transfer to the optical magneto trap in the intercombination line and thus continue with the second stage of the project.