RENATO YOICHI RIBEIRO KURAMOTO

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Agora exibindo 1 - 4 de 4
  • Artigo IPEN-doc 11000
    Rossi-alfa experiment in the IPEN/MB-01 research reactor
    2005 - KURAMOTO, R.; SANTOS, A.; JEREZ, R.; BITELLI, U.D.; DINIZ, R.; MADI FILHO, T.; SANTOS, S.C.
  • Artigo IPEN-doc 11802
    Absolute measurement of βeff based on Feynman-α experiments and the two-region model in the IPEN/MB-01 research reactor
    2007 - KURAMOTO, RENATO Y.R.; SANTOS, ADIMIR dos; JEREZ, ROGERIO; DINIZ, RICARDO
    A new methodology for absolute measurement of the effective delayed neutron fraction βeff based on Feynman-α experiments and the two-region model was developed. This method made use of Feynman-α experiments and the two-region model. To examine the present methodology, a series of Feynman-α experiments were conducted at the IPEN/MB-01 research reactor facility. In contrast with other techniques like the slope method, Nelson-number method and 252Cf-source method, the main advantage of this new methodology is to obtain βeff with the required accuracy and without knowledge of any other parameter. By adopting the present approach, βeff was measured with a 0.67% uncertainty. In addition, the prompt neutron generation time, Λ, and other parameters, was also obtained in an absolute experimental way. In general, the measured parameters are in good agreement with the values found from frequency analysis experiments. The theory-experiment comparison for the βeff measured in this work shows that JENDL3.3 presented the best agreement (within 1%). The reduction of the 235U thermal yield as proposed by Okajima and Sakurai is completely justified according to the βeff measurements performed in this work.
  • Artigo IPEN-doc 13041
    Absolute measurement of βeff based on Rossi-α experiments and the two-region model in the IPEN/MB-01 research reactor
    2008 - KURAMOTO, RENATO Y.R.; SANTOS, ADIMIR dos; JEREZ, ROGERIO; DINIZ, RICARDO
    A new method for absolute measurement of the effective delayed neutron fraction βeff based on Rossi-α experiments and the two-region model was developed at the IPEN/MB-01 Research Reactor facility. In contrast with other techniques such as the slope method, the Nelson-number method, and the 252Cf-source method, the main advantage of this new methodology is to obtain the effective delayed neutron parameters in a purely experimental way, eliminating all parameters that are difficult to measure or calculate. In this way, Rossi-a experiments for validation of this method were performed at the IPEN/MB-01 facility, and with the use of the present approach, βeff was measured with a 1.46% uncertainty. In addition, the prompt neutron generation time A and other parameters were also obtained in an absolute experimental way. In general, the final results agree well with values from frequency analysis experiments. Comparison of theory and experiment reveals that JENDL-3.3 shows deviation for βeff lower than 1%, which meets the desired accuracy for the theoretical determination of this parameter. This work supports the reduction of the 235U thermal yield, as proposed by Okajima and Sakurai.