Banca de DEFESA: TARCIO HENRIQUE RIBEIRO DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : TARCIO HENRIQUE RIBEIRO DOS SANTOS
DATA : 15/09/2020
HORA: 14:00
LOCAL: ConferênciaWeb https://conferenciaweb.rnp.br/webconf/ppgfisdefesas
TÍTULO:

IMPLEMENTATION OF A LABORATORY OF SAMPLE PREPARATION FOR 14C DATING MASS SPECTROMETRY WITH ACCELERATOR

PALAVRAS-CHAVES:

dating, mass spectrometry, grafitization, isotopes, radiocarbon

PÁGINAS: 72
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

The study of the carbon cycle and, especially, its 14C radioactive isotope, has provided a solution to a number of problems concerning marine, geological, environmental, archaeological, and other processes. The development of the radiocarbon dating technique has taken place since 1950 by measuring the decay rate of this isotope. With the development of mass spectrometry with particle accelerators it became possible to date samples smaller than 1 mg. In this thesis, we install a Sample Preparation Laboratory for 14C Dating, the third in the country, after LAC-UFF and 14C Carbon Laboratory of the Center for Nuclear Energy in Agriculture at the University of São Paulo (USP), using the mass spectrometry technique with accelerators and, in future, apply it in paleoenvironmental, archaeological and other studies. The creation of this new laboratory is inserted in the INCT- Nuclear Physics and Applications project and has the main collaboration of the Samples-14 Carbon Laboratory (LAC) in Physics Institute of the Fluminense Federal University (UFF). In the implementation of this laboratory a comparison work with reference materials, C2, C6, C9 and OXII, transformed into graphite at UFBA. Part of the graphites produced were sent to LAC-UFF for measurement of 14C by AMS, in order to validate our preparation routine as regards the absence of contamination and another part of the graphite were made δ 13C measurements in the EA-IRMS to study the isotopic fractionation and the graphitization reaction yield. The measurements of isotopic ratio of materials C2, C6, C9 and OXII provided results with yield of the graphite produced (< 50%),accompanied by isotopic fractionation with an average difference of −9,17ooo. Lastly, the implementation of this laboratory in Bahia will make the research area more accessible, mainly, to the North and Northeast regions of Brazil.

MEMBROS DA BANCA:
Externo à Instituição - ANA CECILIA RIZZATTI DE ALBERGARIA BARBOSA
Externo à Instituição - CARLA REGINA ALVES CARVALHO
Interno - 1194490 - IURI MUNIZ PEPE
Externo ao Programa - 3140683 - JOSE MARQUES LOPES
Interno - 2349838 - MARIA DO ROSARIO ZUCCHI