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Present in many experiments, wire and drift chambers have been used in a large variety of shapes and configurations during the last decades. Nevertheless, their readout elements has not evolved much: tungsten, sometimes gold-plated or aluminum, wires. By taking advantage of the developments in the manufacture of conducting carbon fiber, we could obtain interesting improvements for wire detectors. In this article, we present recent tests and simulations using carbon fibers to readout signal in place of traditional tungsten wires. Unlike metallic wires, their low weight guaranties a reduced quantity of material in the active area.

The measurement of gamma rays in the 0.3–30 MeV energy range with silicon detectors at room temperature via Compton scattering is being investigated for the next spatial gamma-ray observatory in the MeV band. In this contribution, we show that 60-keV gamma-ray detection with an energy resolution below 10 keV is possible using a 64×64 mm2, 1.5-mm thick, double-sided stripped silicon detector with a charge-sensitive preamplifier made of discrete commercial components. Our study of the noise including the bias circuit and the connection between the detector and the electronics allowed us to design a system able to sustain a leakage current of ∼50 nA/strip and a capacitance of ∼20 pF/strip. These results encourage us to investigate the use of integrated electronics in view of a satellite mission.

Astronomy in the MeV gamma-ray band (0.1 - 100 MeV) holds a rich promise for elucidating many fundamental questions concerning the most violent cosmic phenomena. The next generation of gamma-ray space instrument could be a Compton and pair-creation telescope made of two main parts: a silicon tracker optimized for Compton scattering of cosmic gamma rays and a calorimeter that absorbs the scattered photons. We present here the first results of GAMCOTE, a GAMma-ray COmpton TElescope prototype which includes thick double sided silicon strip detectors coupled to a LaBr3:Ce crystal read by a 64 multi-anode photomultiplier tube.

Pulse shape analysis for light particles ( $Z \leq 2$ ) is studied in a 500 μm thick Double-Sided Stripped Silicon Detector (DSSSD) of nTD type with a pitch lower than 500 μm. Good separation between the $Z = 1$ isotopes is achieved irrespective of the side used for signal pick up with the detector biased at depletion voltage. The low energy threshold for discrimination between $Z = 1$ isotopes is found to be around 2.5 MeV at depletion voltage and the quality of the separation can be slightly improved by using filtering methods. On the other hand, the discrimination performances are enhanced when lowering the bias of the detector at the expense of energy resolution. At nominal bias (i.e. overdepletion) where the energy resolution is the best, no separation between the three hydrogen isotopes is achieved when using the amplitude of the current signal. Discrimination can still be obtained by acquiring the time over a threshold set at 10% of the amplitude after applying a square bipolar filter to the current signal. Besides, in view of the design of the front-end electronics, the effect of the sampling rate needed for pulse shape analysis has been investigated and shows that below 200 MSa/s, the discrimination quality is strongly reduced.

Identification of the interstrip effects using digital pulse shape analysis is for the first time reported. This study is performed on a highly segmented double-sided silicon detector used in a nuclear reaction in which a large range of particles at different energies are produced. The output current pulse of the preamplifier is employed as observable. The interstrip effects diminish the capability of particle identification at energies below 5 MeV, especially on the injection side of the detector.

We achieved particle separation of proton, deuteron and triton at energies ranging between 2 and 10 MeV by the processing of digitized signals obtained with a double-sided, 485-μm pitch strip, 500-μm thick neutron transmutation doped (nTD) silicon detector. We produced the light charged particles in a nuclear reaction induced by a 34-MeV beam of 7Li impinging on a 12C target. We analyzed offline the signals with the goal of a simplified, possibly analog, front-end electronics in mind for the processing of the 15,000 channels of the new state-of-the-art detectors for low energy nuclear physics like GASPARD, HYDE and TRACE which should make use of such methods. At the optimum bias, using the current amplitude versus charge correlation, we obtain a separation of 3 FWHM between protons and deuteron, and 2 FWHM between deuteron and triton at energies as low as 2 MeV; with a square bipolar filter, suited for simple implementation, we separate them by 4.3 and 2.7 FWHM respectively at 5 MeV.

NESTER SEP ACC; We have developed a new telescope array, dedicated to the study of direct reactions of exotic nuclei on light targets in inverse kinematics. This device, called MUST2, is briefly described, and the results of the first tests performed with an alpha source and Ni beams at 10 and 75 MeV/u on a CDH target are presented.

A new and innovative array, MUST, based on silicon strip technology and dedicated to the study of reactions induced by radioactive beams on light particles is described. The detector consists of 8 silicon strip – Si(Li) telescopes used to identify recoiling light charged particles through time of flight, energy loss and energy measurements and to determine precisely their scattering angle through X, Y position measurements. Each 60×60 mm 2 double sided silicon strip detector with 60 vertical and 60 horizontal strips yields an X – Y position resolution of 1 mm, an energy resolution of 50 keV, a time resolution of around 1 ns and a 500 keV energy threshold for protons. The backing Si(Li) detectors stop protons up to 25 MeV with a resolution of approximately 50 keV. CsI crystals read out by photo-diodes which stop protons up to 70 MeV are added to the telescopes for applications where higher energy particles need to be detected. The dedicated electronics in VXIbus standard allow us to house the 968 logic and analog channels of the array in one crate placed adjacent to the reaction chamber and fully remote controlled, including pulse visualization on oscilloscopes. A stand alone data acquisition system devoted to the MUST array has been developed. Isotope identification of light charged particles over the full energy range has been achieved, and the capability of the system to measure angular distributions of states populated in inverse kinematics reactions has been demonstrated.