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[en] Full text: The detection system is one of the most important aspects of any experimental apparatus. The data quality is a direct consequence of the efficiency and resolution of the detector. One example are the proportional counters which, in its simplest conception, are composed of a wire, placed between two plates, with a kilovolt voltage between them. When a photon passes, it ionizes the gas. The created ions are accelerated by the difference of potential, which can be detected as charge pulses in each end, permitting a precise determination the event position. Several methods have been developed to determine the position of the event in a proportional detector. In this project we will work on the development, characterization and control of a two-dimensional multiwire gas detector that will be used for X-rays experiments (5-8 KeV). This project is been developed in collaboration with the Department of Nuclear Physics of University of Sao Paulo, which has experience with two-dimensional multiwire gas detectors used for heavy ions research. One of the first goals will be to perform modifications in currently available detectors for X-Ray experiment. The modification of the detectors carries several implications, which corresponds to the design of an appropriate window, choice of the internal pressured gas mixture and the setup of the operation and control system. For the windows, some alternatives would be Kapton or Mylar since both materials have low X-Ray absorption and also sufficient high mechanical strength to support the pressure difference (4 atm), even using thin windows. Since the detector will have a reasonable large area (10 x 10cm or larger), the fixation and sealing of the window is an additional problem. As will be shown, several tests have been already performed both for the test of the electronics and control of the system and also the development of solutions for window fixation and sealing. (author)

[en] High-p_T measurements in relativistic heavy ion collisions provide a unique set of tools to investigate the early stages of the collision. In this paper we report the high-p_T measurements of inclusive hadron spectra, azimuthal anisotropies and two particle correlations performed by the STAR detector for 200 GeV Au+Au, p+p and d+Au collisions at RHIC. The results suggest that the phenomena observed uniquely in central Au+Au collisions are due to strong final state interactions in the hot and dense medium created in such collisions. (author)

[en] The study of heavy flavor production in relativistic heavy ion collisions is an extreme experimental challenge but provides important information on the properties of the Quark-Gluon Plasma (QGP) created in Au + Au collisions at RHIC. Heavy quarks are believed to be produced in the initial stages of the collision, and are essential on the understanding of parton energy loss in the dense medium created in such environment. Moreover, heavy-flavor quarkonium production is an important tool to understand deconfinement. In this work we review recent results on open heavy flavor and quarkonium production and their interaction with the hot and dense medium at RHIC. (author)

[en] The STAR (Solenoidal Tracker at RHIC) experiment is a large acceptance collider detector that measures primarily hadronic observables to search for signatures of the quark-gluon plasma phase transition and study strongly interacting matter at high energy density. Operational since June 2000, the new heavy ion collider RHIC has already provided Au+Au collisions at √(σ_NN) = 62, 130 and 200 GeV as well as p+p and d+Au collisions at 200 GeV. The various collision energies and systems allow the systematic study of particle production in heavy ion collisions. In particular, the production of strange (anti-)particles is one of the major topics of STAR. This detector allows the measurement of a variety of particle species at mid-rapidity, like neutral kaons; Λ, Ξ, and Ω. hyperons; and their anti-particles that are reconstructed via their decay topology. The strangeness measurements should provide important information on various phenomenological aspects of ultra-relativistic heavy ion collisions. The goal of this work is to perform the measurement of neutral kaons on Au+Au collisions at 62 GeV. This measurement will bring important information about strangeness production in the energy range between the top RHIC energy and the top SPS energy, where important questions regarding particle production are still open. In this poster, preliminary results of the analysis will be presented, mainly the evaluation of the topological cuts necessary for the neutral kaon reconstruction and the corrections that are necessary to obtain the transverse momentum spectra

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[en] Time scales of strongly energy damped and fast processes in light heavy-ion reactions were measured in order to investigate the dynamics involved in the collision. Particle-particle correlation functions at small relative momenta were measured to determine the time scale of sequential particle emission in highly excited light composite systems and the values obtained are compared to the lifetime of the compound nucleus determined by cross section fluctuations measurements. The results indicate that in the case of light nuclear systems, a drastic time scale compression is observed, independent of the inelasticity of the process, in contrast to the case of heavy systems for which the time difference between the fast and slow processes is at least 100-1000 times larger

[en] The dynamical of light-ions (A_CN-20) reactions has been studied for several years by our group. In order to continue this kind of investigation we are interested in determining the time-scales for the fusion-fission process in this mass region by the Ericsson fluctuations technique. Measurements have been done for the system ¹⁶ O + ¹⁰ B at E_Lab-64 MeV with beam energy step of δE_Lab-50 KeV. (author)

[en] Sixteen triple telescopes were developed to be used in the study of light heavy-ion nuclear reactions at the University of Sao Paulo Pelletron Laboratory, with the purpose of providing simultaneous identification of light and heavy reaction products. Each telescope consists of one ionization chamber, one Si detector and one CsI detector with photodiode readout. The telescopes are encapsulated in such a way that they can be utilized in different setup geometries depending on the kind of experiment being performed. Results for the ionization chambers energy loss resolution, Si and CsI detectors energy resolution and general performance are presented