BATS: a Bayesian user-friendly software for Analyzing Time Series microarray experiments

BATS is a user-friendly software for Bayesian Analysis of Time Series microarray experiments based on the novel, truly functional and fully Bayesian approach proposed in Angelini et at. (2006). The software is specifically designed for time series data. It allows an user to automatically identify and rank differentially expressed genes and to estimate their expression profiles. BATS successfully manages various technical difficulties which arise in microarray time-course experiments, such as a small number of observations, non-uniform sampling intervals, and presence of missing or multiple data. BATS can carry out analysis with both simulated and real experimental data. It also handles data from different platforms. 1 Availability: BATS is written in Matlab and executable in Windows (Macintosh and Linux version are currently under development). It is freely available upon request from the authors.

178Hg and asymmetric fission of neutron-deficient pre-actinides

International audienceFission at low excitation energy is an ideal playground to probe the impact of nuclear structure on nuclear dynamics. While the importance of structural effects in the nascent fragments is well established in the (trans-)actinide region, the observation of asymmetric fission in several neutron-deficient pre-actinides can be explained by various mechanisms. To deepen our insight into that puzzle, an innovative approach based on inverse kinematics and an enhanced version of the VAMOS++ heavy-ion spectrometer was implemented at the GANIL facility, Caen. Fission of Hg178 was induced by fusion of Xe124 and Fe54. The two fragments were detected in coincidence using VAMOS++ supplemented with a new SEcond Detection arm. For the first time in the pre-actinide region, access to the pre-neutron mass and total kinetic energy distributions, and the simultaneous isotopic identification of one the fission fragment, was achieved. The present work describes the experimental approach, and discusses the pre-neutron observables in the context of an extended asymmetric-fission island located southwest of Pb208. A comparison with different models is performed, demonstrating the importance of this new asymmetric-fission island for elaborating on driving effects in fission

Shape coexistence in neutron-deficient Hg-188 investigated via lifetime measurements

Shape coexistence in the $Z \approx 82$ region has been established in mercury, lead and polonium isotopes. Even-even mercury isotopes with $100 \leq N \leq 106$ present multiple fingerprints of this phenomenon, which seems to be no longer present for $N \geq 110$. According to a number of theoretical calculations, shape coexistence is predicted in the $^{188}$Hg isotope. The $^{188}$Hg nucleus was populated using two different fusion-evaporation reactions with two targets, $^{158}$Gd and $^{160}$Gd, and a beam of $^{34}$S, provided by the Tandem-ALPI accelerators complex at the Laboratori Nazionali di Legnaro. The channels of interest were selected using the information from the Neutron Wall array, while the $\gamma$ rays were detected using the GALILEO $\gamma$-ray array. The lifetimes of the excited states were determined using the Recoil Distance Doppler-Shift method, employing the dedicated GALILEO plunger device. Using the two-bands mixing and rotational models, the deformation of the pure configurations was obtained from the experimental results. The extracted transition strengths were compared with those calculated with the state-of-the-art symmetry-conserving configuration-mixing (SCCM) and five-dimentional collective Hamiltonian (5DCH) approaches in order to shed light on the nature of the observed structures in the $^{188}$Hg nucleus. An oblate, a normal- and a super-deformed prolate bands were predicted and their underlying shell structure was also discussed.Comment: v1: 13 pages, 10 figures, comparison between IBM-CM and SCCM calculations; v2: 16 pages, 13 figures, discussion on the mixing amplitudes from the experimental B(E2) values, comparison between SCCM and 5DCH calculation

Simulations using the pulse shape comparison scanning technique on an AGATA segmented HPGe gamma-ray detector

International audienceMonte Carlo simulations are used to test the Pulse Shape Comparison Scanning (PSCS) technique implemented at the IPHC scanning table. The technique allows the full volume characterization of a given position sensitive detector resulting in the construction of the corresponding database of pulses. The tests, performed on a high purity germanium (HPGe) detector unit of the AGATA array, aim to quantify the accuracy of the technique and validate it through the evaluation of parameters extracted from the resulting database. The simulations use a combination of tools such as Geant4, SIMION and the Agata Detector Library (ADL). Quality parameters are extracted at various gamma-ray energies and the impact of the input statistics on the parameters is also analyzed

Full-volume characterization of an AGATA segmented HPGe gamma-ray detector using a

Scanning tables use collimated gamma-ray sources to perform full volume characterization of position sensitive detectors. One of such tables is hosted at IPHC Strasbourg. It was designed and built within the AGATA collaboration. It exploits the pulse shape comparison scanning (PSCS) technique to build databases of pulses used to characterize the response of high purity germanium (HPGe) detectors and perform R&D on such crystals. Ultimately, measured databases could be used by the pulse shape analysis (PSA) algorithms employed in AGATA experiments. The table can perform full volume scans of large volume detectors in short times, with a good spatial resolution and at different energies. Lately, the table was upgraded with a new $$^{152}Eu$$ source, which emits gamma rays in cascades of different energies. A scan with such source is performed for the first time. It allows to build different energy databases in one single scan. The present work aims at testing the performances of the PSCS technique with a multi-energetic source and verifying some assumptions of the Shockley–Ramo theorem which are at the base of the PSA algorithms used for gamma-ray tracking arrays

A Digital data acquisition system for PRIN- A Facility for neutron production using Accelerator.

International audienceAll most all the nuclear physics experiments involves ion beam (projectile) of different species and energies. The intensity of the beam, the beam energy, the beam uniformity & divergence including stability of the ion beam is of fundamental importance for any Accelerator. In addition with ion beam the study of neutrons are demanding subject now days. There are lack of reliable nuclear data [1], especially around 5 to 14 MeV range and still it is an open field of study. The neutron cross-section data at these high energies are very much important for fusion reactor development. More over there is a need for calibrated neutron (n) detectors to be used for reliable cross-section measurements. In addition to the above the dark matter group wants to investigate the experimental study using recoil range analysis method in liquid Ar/Xe where they need more precise neutron energy and crosssection. Now days the imaging (neutron imaging) is another emerging field for non-destructive study of many thing starting from industrial to defences research where the high energy neutron cross section are very much important. All the above requirement lead to the development of a dedicated neutron source and dedicated fast data acquisition system which can able to do quick analysis at the site for better understanding. Keeping all the things on mind a dedicated beam line for n production has been developed which uses a two body D(d, n)3He reaction to produce mono energetic neutron [2] of desired energies at 3.3MV Tandem Accelerator (TTT-3) at Department of Physics, University of Naples Federico II [3]. The neutron beam line including specially designed chamber for neutron Production has been shown in Fig.1. There are many other reactions are available to produce neutron whereas D(d, n)3He reaction has some better advantage which will be presented and discussed. To support the above experimental facility a dedicated digital data acquisition system have been installed and new algorithm using ROOT has been developed for the analysis purpos