[en] Experiment PREX will take place in Hall A at TJNAF in 2010. It will measure the neutron radius R_n in the ²⁰⁸Pb nucleus through the measurement of the parity violating asymmetry in electron scattering A_PV = σ_R-σ_L/σ_R+σ_L, with σ_R and σ_L the cross sections for right handed and left handed electrons respectively. The projected accuracy of 1% on R_n constitutes a fundamental test of nuclear theory. This measurement of R_n will provide the best determination of the density dependence of the symmetry energy at the density of ordinary nuclear matter. As a consequence, the PREX result will have a big impact on phenomena like neutron star structure, heavy ion collisions and atomic parity violation.

[en] A review of the experiments that measured the Parity Violating asymmetry in electron scattering is given. A description of the experimental apparatus and of the employed techniques as well as of the goals achieved is given for each experiment. The most important experiments that in the near future will perform Parity Violating asymmetry measurements and the physics fields interested by them (above all the search for physics Beyond the Standard Model) are provided.

No abstract available

[en] Hypernuclear spectroscopy of several hypernuclei is going to be performed in Hall A of the Thomas Jafferson Laboratory (JLab). With the JLab good quality beam and the High Resolution Spectrometers installed in Hall A, the resolution achievable will be of the order of 350 KeV and it should be possible to discern some of the spin doublet in the hypernuclear spectra improving our knowledge on Λ-nucleon interaction. Two septa have to be added to the HRS spectrometers, in order to make them able to detected very forward scattered particles and increase in this way the event rate. This paper starts with a short review of the physics goals that can be achieved by hypernuclear spectroscopy and of the different kinds of information that can be obtained using hadronic and electromagnetic probes. After the description of the JLab accelerator, Hall A and HRS spectrometer characteristics, it explains the hypernuclear program scheduled in Hall A, the changes needed to the experimental apparatus in order to perform it, and at last the problems created by the expected high single counting rates and the particle identification (PID) system. (S.Y.)

[en] The strangeness electroproduction experiments, just starting to take data at TJNAF, are very promising for giving very useful information to understand the nuclear and nucleonic structure and reaction mechanism. The experimental program on hypernuclei already approved concerns few body, light nuclei and heavy nuclei. It will be possible to investigate these hypernuclear systems for the first time by photo- and electro-induced reactions, allowing to obtain very useful information such as Λ-N interaction and weak interaction in the nuclear medium in a complementary way with respect to what can be done with hadron probes

[en] Mammoscintigraphy is an important tool for secondary breast cancer screening. Good results have been achieved with dedicated gamma cameras for T_1b tumors (size >5 mm). We have performed simulations and measurements in order to improve the performance of compact gamma cameras for detecting T_1a tumors (size <5 mm). Preliminary results of the simulation show that the best performance can be obtained using CsI(Tl) segmented scintillators (2x2x3 mm³) coupled with a Position Sensitive Photomultiplier Tube (PSPMT) having a multianode structure (2x2 mm² pad size). Measurements allowed to test the validity of the simulation software

[en] Nuclear Medicine methods have been proposed as a means of imaging primary breast lesions and regional metastatic involvement based on tumor physiology. Recently, the positive predictive value of scintimammography using ⁹⁹Tc labelled SestaMIBI has been reported to be as high as 81%, with an associated negative predictive value of 97%. Visualization of small (<1 cm) lesions using scintimammography may be complicated, however, by the effects of overlying and underlying background uptake of MIBI in the breast soft tissue and the deterioration of lesion contrast with distance from the gamma camera. For these reasons dedicated compact gamma cameras have been proposed and successfully used. Nevertheless, the detection of very small tumors (<5-10 mm) is still very difficult. Many parameters affect the breast small tumors detection. The degree of pixellation of both the scintillator and photodetector is critical for the intrinsic position resolution of the detector and for the overall imaging performance. In this paper, we examine the basic imaging properties of systems using arrays of scintillators and pixellated photodetectors. The influence of readout systems is also taken into account. Simulations as well as preliminary experimental results are presented

[en] The high-resolution hypernuclear spectroscopy experiment at Jefferson Lab, Hall A (E94-107), needs unambiguous kaon identification. Due to the huge pion and proton background, the standard Hall A hadron particle identification, based on a time of flight and two aerogel threshold Cherenkov detectors, is not sufficient. For this task a proximity focusing C₆F₁₄/CsI RICH has been built. Recently, after some improvements to the mechanical structure of its wire chamber and to its electronics rate capability, the RICH has been tested with cosmic rays. This paper represents a status report of the RICH detector

[en] Over the last few years our interest was dedicated to the development of small field of view imagers for Nuclear Medicine applications, particularly in Oncology. Some years ago, the authors have described an original scintillation gamma camera based on a matrix of 2x2 R5900-C8 Hamamatsu Position Sensitive PhotoMultiplier Tube (PSPMT) coupled to a scintillating array. The intrinsic spatial resolution obtained was adequate for high-resolution imaging applications. On the contrary, the prototype was affected by reduced performances at the borders between PSPMT. The subsequent introduction by Hamamatsu of the R7600 flange-less PSPMT family allowed to reduce the dead areas at the borders. Furthermore, Hamamatsu R7600-C12 model, improving the charge sampling with lower anode pitch, allows to improve the spatial resolution and to optimize the spatial response. Good performance was obtained with 2x2 R5900-C8 PSPMT array with a Combined Array-Planar Crystal (CAPC) geometry, designed by the authors. It consists of a planar crystal segmented in the top in a 15x15 array, 3 mm square pixel, 1 mm thick, and 0.25 mm gap. Hilger manufactured two CsI assemblies, Na and Tl doped, respectively, for this study

[en] Updated results of the experiment E94-107 hypernuclear spectroscopy in Hall A of the Thomas Jefferson National Accelerator Facility (Jefferson Lab), are presented. The experiment provides high resolution spectra of excitation energy for ¹²BΛ, ¹⁶NΛ, and ⁹LiΛ hypernuclei obtained by electroproduction of strangeness. A new theoretical calculation for ¹²BΛ, final results for ¹⁶NΛ, and discussion of the preliminary results of ⁹LiΛ are reported.