A recoil separator for the measurement of radiative capture reactions Gialanella, L; Strieder, F; Brand, K ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/1996, Volume:
376, Issue:
2
Journal Article
Peer reviewed
A recoil separator in combination with a windowless gas target has been designed for the measurement of the radiative capture reaction
p(
7Be
, γ)
8B
. The separator consists of momentum and velocity ...filters and a
ΔE−
E detector telescope. The setup was tested quantitatively using the
p(
12C
, γ)
13N
reaction at the effective energy
E
cm = 841 keV. Projectile fluxes were measured directly with Faraday cups and indirectly with elastic backscattering into Si detectors, while the
13N recoil flux was measured directly with the
ΔE−
E telescope. A suppression of the
12C
beam particles by a factor 2 × 10
−10 was observed when the system was tuned for the recoil
13N's
. Special emphasis was given to the charge state probabilities of the
13N
recoils. Possible improvements of the system for the measurement of other capture reactions are discussed.
Using the 50 kV LUNA accelerator facility at the Gran Sasso underground laboratory we measured, with an accuracy of the order of 10%, the d(p,
γ)
3He cross section from 22 down to 2.5 keV c.m. ...energy, well below the solar Gamow peak. The experimental set-up was based on a large solid angle, segmented BGO detector and a renewed windowless gas target. The astrophysical
S(
E) factor within the Gamow peak is in fair agreement with the value of one of the existing extrapolations of data at higher energies.
Nanotechnology: A new era for photodetection? Ambrosio, M.; Ambrosio, A.; Ambrosone, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2009, Volume:
610, Issue:
1
Journal Article
Peer reviewed
Open access
Nowadays we live in the so-called “Silicon Era”, in which devices based on the silicon technology permeate all aspects of our daily life. One can simply think how much silicon is in the everyday ...household objects, gadgets and appliances.
The impact of silicon technology has been very relevant in photodetection as well. It enables designing large or very large-scale integration devices, in particular microchips and pixelled detectors like the Silicon Photo Multiplier made of micrometric channels grouped in mm
2 pixels. However, on the horizon, the recent development of nanotechnologies is opening a new direction in the design of sub-micron photodevices, owing to the capability to deal with individual molecules of compounds or to chemically grow various kinds of materials.
Among them, carbon compounds appear to be the most promising materials being chemically very similar to silicon, abundant and easy to handle. In particular, carbon nanotubes (CNT) are a very intriguing new form of material, whose properties are being studied worldwide providing important results.
The photoelectric effects observed on carbon nanotubes indicate the possibility to build photodetectors based on CNTs inducing many people to claim that we are at the beginning of a Post Silicon Era or of the Carbon Era.
In this paper, we report on the most important achievements obtained on the application of nanotechnologies to photodetection and medical imaging, as well as to the development of radiation detectors for astro-particle physics experiments.
The cross section of the reactions
3He(d,
p)
4
He and d(
3He,
p)
4He has been measured at the center-of-mass energies
E=5 to 60 keV and 10 to 40 keV, respectively. The experiments were performed to ...determine the magnitude of the electron screening effect leading to the respective electron-screening potential energy
U
e
=219±7
and
109±9 eV, which are both significantly higher than the respective values from atomic physics models,
U
e
=120
and 65 eV.
In the framework of Coulomb dissociation experiments, performed to reconstruct the cross section of the inverse radiative capture process, the detection of breakup fragments is usually performed ...using separate detectors, which unavoidably are not sensitive to small relative angles. It is shown, by means of Monte Carlo simulations, that the phase-space constraints imposed by the detection geometry can bias, specially at very low relative energies, the extracted cross section, which turns out to be strongly dependent upon the assumed angular distribution of fragments in the intrinsic reference frame. A solution to the problem of the model-dependence of the response function is proposed, making use of a single three-stage detector for the identification and the relative energy measurement of the breakup fragments. A test measurement on the reaction
208Pb(
16O,
12C-
α)
208Pb at 126
MeV incident energy has been performed, using a gas–Si–CsI tritelescope. The results indicate the feasibility of measuring very low relative energies in the Coulomb dissociation approach to the solution of important problems in nuclear astrophysics via the accurate determination of reaction rates at energies far below the Coulomb barrier.
CdTe crystals grown by the Traveling Heater Method (THM) often show a pronounced non-uniformity along the ingots due to the thermal irregularities, the Te-excess growth conditions resulting from the ...retrograde slope of the solidus line of the phase diagram, and to the introduced impurities. In addition, structural defects can be present that affect the electrical and optical properties of the crystals. X-ray and alpha particle spectroscopy measurements have been performed on differently prepared CdTe samples (as grown or annealed, different surface treatments, etc.) with Pt electrodes deposited by electroless technique in order to extract the typical figures of merit of the material and the detectors. Moreover, Rutherford Backscattering Spectrometry (RBS) using 8 MeV 7 Li +++ ions and X-Ray Fluorescence (XRF) using a Pd-anode X-Ray generator were performed to characterize the crystal surface as well as the semiconductor-electrode interface. In addition, contactless resistivity and mutau product mapping technique, infrared microscopy imaging and electrical and spectroscopy measurements have been used for material characterisation. The aim of this work is to determine in a routine way the best suited method to fabricate high-quality X- and Gamma-ray detectors to be used both as large size simple detectors and as elements of imaging systems in medical or industrial applications as well as to understand and improve the structure of the material-electrode interface. The thickness, the stoichiometry and the concentration profiles of platinum, cadmium and tellurium present at the surface layers were determined. The distribution of Cd deficiency at the interface layers was profiled using simulations and showed complex profiles in the samples, which can greatly affect the electrical quality of the detectors
EBOFERA: A companion for FERA ADCs Ordine, A.; Boiano, A.; Parascandolo, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1997, Volume:
390, Issue:
3
Journal Article
Peer reviewed
A data transfer problem using FERA modules was found in a heavy ion nuclear physics experiment. The source of the problem was spotted in the handling of some signals on the FERA control bus. A ...modification of this handling is proposed and performed by means of a new CAMAC-FERA control module, the EBOFERA. Furthermore, this module has a number of useful features like the master gate and clear signals handling, event tagging, pattern unit and event counter.
Nuclear fusion reactions play a key role in the understanding of energy production, neutrino emission and nucleosynthesis of the elements in stars. The direct measurement of the cross section of ...these reactions at the relevant energies is usually hampered by cosmic radiation, beam induced background and/or the radioactivity of the nuclei involved. The measurements are expected to be completed by fall 1996.
