Riptide is a detector concept aiming to track fast neutrons. It is based on neutron--proton elastic collisions inside a plastic scintillator, where the neutron momentum can be measured by imaging the ...scintillation light. More specifically, by stereoscopically imaging the recoil proton tracks, the proposed apparatus provides neutron spectrometry capability and enable the online analysis of the specific energy loss along the track. In principle, the spatial and topological event reconstruction enables particle discrimination, which is a crucial property for neutron detectors. In this contribution, we report the advances on the Riptide detector concept. In particular, we have developed a Geant4 optical simulation to demonstrate the possibility of reconstructing with sufficient precision the tracks and the vertices of neutron interactions inside a plastic scintillator. To realistically model the optics of the scintillation detector, mono-energetic protons were generated inside a \(6\times6\times6\) cm\(^3\) cubic BC-408 scintillator, and the produced optical photons were propagated and then recorded on a scoring plane corresponding to the surfaces of the cube. The photons were then transported through an optical system to a \(2\times2\) cm\(^2\) photo sensitive area with 1 Megapixel. Moreover, we have developed two different analysis procedures to reconstruct 3D tracks: one based on data fitting and one on Principal Component Analysis. The main results of this study will be presented with a particular focus on the role of the optical system and the attainable spatial and energy resolution.
Fast neutron detection is often based on the neutron-proton elastic scattering reaction: the ionization caused by recoil protons in a hydrogenous material constitutes the basic information for the ...design and development of a class of neutron detectors. Although experimental techniques have continuously improved, proton-recoil track imaging remains still at the frontier of n-detection systems, due to the high photon sensitivity required. Several state-of-the-art approaches for neutron tracking by using n-p single and double scattering - referred to as Recoil Proton Track Imaging (RPTI) - can be found in the literature. So far, they have showed limits in terms of detection efficiency, complexity, cost, and implementation. In order to address some of these deficiencies, we have proposed RIPTIDE a novel recoil-proton track imaging detector in which the light output produced by a fast scintillator is used to perform a complete reconstruction in space and time of the interaction events. The proposed idea is viable thanks to the dramatic advances in low noise and single photon counting achieved in the last decade by new scientific CMOS cameras as well as pixel sensors, like Timepix or MIMOSIS. In this contribution, we report the advances on the RIPTIDE concept: Geant4 Monte Carlo simulations, light collection tests as well as state-of-the-art approach to image readout, processing and fast analysis.
The electromagnetic calorimeter of the HERA-B experiment Avoni, G.; Baldanza, C.; Bertin, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2007, Letnik:
580, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The electromagnetic calorimeter of the
HERA-B experiment built at the HERA proton accelerator at DESY (Hamburg) is described. The construction characteristics of the detector, of the related ...front-end, readout, trigger and service electronics are discussed together with the constraints and the motivations which inspired the design philosophy. The detector performance are presented as obtained from the analysis of the data acquired during the
HERA-B running period, including calibration procedures and achievements and the electron identification capability exploiting a method, proposed here for the first time, based on the observation of the associated bremsstrahlung
γ
. Finally, some observed physical signals and a short overview of the main obtained physics results are presented.
is a fixed target experiment working on the 920 GeV proton beam of the HERA accelerator at the DESY laboratory in Hamburg. During the last data taking period (2002-2003), about 150 million dilepton ...triggers, 220 million minimum bias events and 35 million hard photon triggers were acquired. These large statistics allow detailed studies on the production of charmonium states in proton-nucleus p-A collisions, which extend for the first time into the negative Feynman-x () region. Measurements of the inclusive , \(\Upsilon\) and open charm cross sections are also ongoing. After a brief discussion of the detector and of the data samples, we report on preliminary results obtained on these physics topics.
The bb¯ production cross section in 920 GeV proton-nucleus fixed target collisions is measured by observing double muonic decays of b-flavoured hadrons in the kinematic region −0.3<xF(μ)<0.15. A ...total number of 83±12bb¯ events is obtained with a likelihood fit of the signal and background simulated events to the data. The resulting cross section is σbb¯=17.5±2.6stat±3.3sys nb/nucleon, or, when combined with a previous HERA-B measurement of similar precision, σbb¯=15.8±1.7stat±1.3sysuncorr±2.0syscorr nb/nucleon, which is consistent with recent NLO calculations.
By exploiting the triple-well option available in a deep-submicron CMOS process, we developed monolithic active pixel sensors (MAPS) with the unique features of full analog signal processing and ...digital functionality implemented at the pixel level. After briefly reviewing the results achieved with the first prototype chip, we report on the extensive measurements on the second prototype, containing both single-channel sensors, with an improved noise figure, and an
8
×
8
pixel array. For the pixel having a collecting electrode area of
900
μ
m
2
we measured an equivalent noise charge of about 40 electrons. Using the
Fe
55
5.9
keV line, we obtained a Signal-to-noise (S/N) ratio of about 30. The pixel matrix
(
50
×
50
μ
m
2
)
has been successfully readout up to 30
MHz. Through noise scans, an expected significant threshold dispersion has been measured.
The measurements presented in this paper confirm the capability of our MAPS, based on the deep n-well concept, to be operated as ionizing radiation detectors and suggest a series of improvements we are already implementing in the design of the next prototype chip.
Using data collected by the HERA-B experiment, we have measured the fraction of J/ψ's produced via radiative χc decays in interactions of 920 GeV protons with carbon and titanium targets. We obtained ...Rχc=0.32±0.06stat±0.04sys for the fraction of J/ψ from χc decays averaged over proton–carbon and proton–titanium collisions. This result is in agreement with previous measurements and is compared with theoretical predictions.
The cross section ratio RJ/ψ=Br(ϒ→l+l−)⋅dσ(ϒ)/dy|y=0/σ(J/ψ) has been measured with the HERA-B spectrometer in fixed-target proton–nucleus collisions at 920 GeV proton beam energy corresponding to a ...proton–nucleon c.m.s. energy of s=41.6 GeV. The combined results for the decay channels ϒ→e+e− and ϒ→μ+μ− yield a ratio RJ/ψ=(9.0±2.1)×10−6. The corresponding ϒ production cross section per nucleon at mid-rapidity (y=0) has been determined to be Br(ϒ→l+l−)⋅dσ(ϒ)/dy|y=0=4.5±1.1 pb/nucleon.
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