Cold Collisions
Mostrando 1-12 de 15 artigos, teses e dissertações.
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1. Montagem e caracterização de uma armadilha magneto-óptica de rubídio / Mounting and characterization of a rubidium magneto-optical trap
In this work we present the building and characterization of a Magneto-Optical Trap (from now on named MOT) for Rubidium atoms. We perform experiments for studying the eect of a broadband light over trapped atoms. In order to carry out this study we used a incandescent lamp which is broad in the wavelength spectrum. We observed in a MOT, with a number of 109
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/07/2011
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2. Sobre a dinâmica das colisões atômicas frias controladas em redes ópticas / On the dynamic of the cold atomic controlled collisions in optical lattices
Partindo de uma derivação matemática do modelo de Bose-Hubbard, desenvolvemos os cálculo para o emaranhamento bi e multipartido, através da transição Isolante de Mott-superuida, entre os modos de uma rede óptica para as situações mais simples de dois, três e quatro átomos (N) depositados nestas com igual número de sítios M, ocasionando um fator
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/06/2011
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3. Armadilha de dipolo para átomos e moléculas / A dipole trap for atoms and molecules
Neste trabalho apresentamos a construção de um novo sistema experimental para aprisionamento de átomos e moléculas. Trata-se de uma armadilha de dipolo cruzada totalmente óptica, formada por um laser de fibra com 40 W de potência com comprimento de onda em 1064 nm. Nesse sistema foi demonstrado o aprisionamento de átomos Rb e K e moléculas Rb2. Reali
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/05/2011
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4. Photoassociative ionization in situations with low dimensions / Investigação do processo de foto-ionização associativa em situações com baixa dimensão
Photoassociative ionization (PAI) in a cold sample of sodium atoms was the main subject of our studies as a way to understand the effects of repulsive states and collision dimensions. Two-color PAI experiment were preformed in a magneto-optical trap (MOT) trough the addition of a probe laser beam, the intensity, polarization and frequency of that probe laser
Publicado em: 2009
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5. A construção teórica do conceito de legitimidade no direito internacional : a inaplicabilidade da Norma Fundamental da Teoria Pura do Direito de Hans Kelsen
This thesis focuses on the hypothesis of the inapplicability of the kelsenian basic norm as a single assumption of legitimacy concerned to international law and has as its purpose the study of the historical evolution of ideas concerning the international legal system, mainly established during the 20th century, taking as a point of reference the analysis of
Publicado em: 2009
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6. Open charm tomography of cold and hot nuclear matter
We identify the nuclear effects that modify the cross sections for open heavy flavor production in proton-nucleus and nucleus-nucleus collisions. In p+A reactions, we calculate and resum the coherent nuclear-enhanced power corrections from the final-state parton scattering in the medium. We find that single and double inclusive open charm production can be s
Braz. J. Phys.. Publicado em: 2007-06
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7. Jet tomography of quark gluon plasma
Recent experimental measurements of high pT hadron spectra and jet correlation at RHIC are analyzed within a parton model which incoporates initial jet production and final propagation in heavy-ion collisions. The suppre-sion of single hadron spectra, back-to-back correlation, their centrality dependence and azimuthal anisotropy point to a dense matter with
Brazilian Journal of Physics. Publicado em: 2004-12
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8. Modeling of low-altitude quasi-trapped proton fluxes at the equatorial inner magnetosphere
A secondary proton radiation belt can be observed in the equatorial region between the upper atmosphere and the interior edge of the main radiation belt. It is thought that the protons appear there in a result of ionization of energetic neutral hydrogen atoms coming from the internal area of the traditional radiation belt where they were born in charge excha
Brazilian Journal of Physics. Publicado em: 2003-12
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9. Desenvolvimento de fontes laser, espectroscopia de alta resolução e resfriamento e aprisionamento magneto-optico de atomos de calcio
In this work, we report on an experimental system for laser cooling and magneto-optical trapping of calcium atoms, the development of the laser sources for this system, and a spectroscopic analysis of calcium transitions in hollow cathode electric discharges. In the case of calcium, the most efficient optical transition for the atom motion manipulation by ra
Publicado em: 2002
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10. Estudo de taxas de perdas em sistemas heteronucleares / Trap loss in a two-species Rb-Cs magneto-optical trap
In this work, we had investigated the heteronuclear trap loss rate in a two-species Rb-Cs magneto-optical trap. The experimental results suggest that radiative escape is the main collisional process responsible for heteronuclear losses. An addapted Gallagher - Pritchard model is compared with the data. The model is very sensitive to the trap depth, which dep
Publicado em: 2001
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11. Estudo de colisões inelásticas heteronucleares no sistema rubídio(Rb)/césio(Cs) em regimes de baixas temperaturas. / Study of heteronuclear inelastic collisions in a rubidium (Rb)/ Cesium (Cs) system under low temperature.
Armadilhamento duplo de átomos neutros constitui um dos avanços mais recentes no estudo de colisões frias. Obtivemos experimentalmente as taxas de perda devido a interação de espécies alcalinas mistas (Cs/Rb). Utilizamos uma armadilha magneto-óptica mista operando com feixes de alta intensidade permitindo o resfriamento e confinamento das amostras com
Publicado em: 1999
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12. Perdas colisionais devido ao processo de mudança de estrutura fina em uma armadilha magneto-óptica de rubídio / Fine structure changing collisional losses in a rubidium magneto-optical trap
We report the observation of trap-loss collisional rates due to fine structure changing collisions between cold and trapped 85Rb atoms. We have measured, by photoionization of the atomic fragments in 5P1/2 state originated in these collisions, the rates through the atoms leave the trap induced by this loss mechanism. We carried out experiments to determine t
Publicado em: 1999