Abstract
Within the frame of the EKATϒ programme, whose purpose is the innovative imaging of the subsurface of archaeological sites and the interior of structural elements of monuments in “three” and ...“four” dimensions, the applicability of Muon Tomography technique in the representation of a tumulus is tested in the present work. The scanning of its internal structure is accomplished by measuring the flux deficit of cosmic muon tracks in the presence of an object inside the tumulus, compared to the muon flux when traversing a uniform tumulus (transmission muography). The feasibility study of the method is achieved with a simulation of the tumulus geometry and the structure under investigation. Following the simulation process, a tracking telescope, consisting of four MicroMegas detectors and two trigger plastic scintillators, will be placed near Apollonia’s tumulus to collect data. For the specific latitude where the Apollonia’s tumulus is located, the energy and angular muon distribution at sea level is studied. Implementing the dimensions of the telescope in the simulation, the back-projection method is examined for the localization of the hidden object and the estimation of its dimensions. The method is tested for the telescope optimal position, placed under the tumulus, and the realistic one, placed near the tumulus at the level of its base.
A novel MicroMegas detector based on microbulk technology with an embedded XY strip structure was developed, obtained by segmenting both the mesh and the anode in perpendicular directions. This ...results in a very low-mass device with good energy and spatial resolution capabilities. Such a detector is practically “transparent” to neutrons, being ideal for in-beam neutron measurements and can be used as a quasi-online neutron beam profiler at neutron time-of-flight facilities. A dedicated front end electronics and acquisition system has been developed and used. The first studies of this new detection system are presented and discussed.
Drift velocity and gain in argon- and xenon-based mixtures Andronic, A.; Biagi, S.; Braun-Munzinger, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2004, Volume:
523, Issue:
3
Journal Article
Peer reviewed
We present measurements of drift velocities and gains in gas mixtures based on Ar and Xe, with CO
2, CH
4, and N
2 as quenchers, and compare them with calculations. In particular, we show the ...dependence of Ar- and Xe–CO
2 drift velocities and gains on the amount of nitrogen contamination in the gas, which in real experiments may build up through leaks. A quantification of the Penning mechanism which contributes to the Townsend coefficients of a given gas mixture is proposed.
The recently developed Spherical Proportional Counter 1 allows to instrument large target masses with good energy resolution and sub-keV energy threshold. The moderate cost of this detector, its ...simplicity and robustness, makes this technology a promising approach for many domains of physics and applications, like dark matter detection and low energy neutrino searches. Detailed Monte Carlo simulations are essential to evaluate the background level expected at the sub-keV energy regime. The simulated background here, it refers to the contribution of the construction material of the detector and the effect of the environmental gamma radiation. This detector due to its spherical shape could be also served as an optical photon detector provided it is equipped with PMTs, for Double Beta decay and Dark Matter searches. All calculations shown here are obtained using the FLUKA Monte Carlo code.
The Spherical Proportional Counter, recently developed, allows to instrument large target masses with good energy resolution and low energy threshold. Ultra low energy results are shown here, leading ...to an energy threshold as low as 25 eV and a single electron detection sensitivity. The bench mark result is the observation of a well resolved peak at 270 eV due to carbon fluorescence, which is a unique performance for such large massive detector. This very promising feature can fulfill the demands of many challenging projects from dark matter detection to low energy neutrino searches. Details of this study are given in reference 1.
A novel large volume spherical proportional counter, recently developed, is used for neutron measurements. The pure N2 gas is studied for thermal and fast neutron detection, providing a new way for ...neutron spectroscopy. The neutrons are detected via the N14(n,p)C14 and N14(n,α)B11 reactions. The detector is tested for thermal and fast neutrons detection with Cf252 and Am241−Be9 neutron sources. The atmospheric neutrons are successfully measured from thermal up to several MeV, well separated from the cosmic ray background. A comparison of the spherical proportional counter with the current available neutron counters is also presented.
In high-energy nuclear collisions the degree of thermalization at the partonic level is a key issue. Due to their large mass, heavy quarks and their possible participation in the collective flow of ...the QCD-medium constitute a powerful probe for thermalization. We present studies with PYTHIA for
pp collisions at the top LHC energy of
s
=
14
TeV
applying the two-particle transverse momentum correlator
〈
Δ
p
t
,
1
,
Δ
p
t
,
2
〉
to pairs of heavy-quark hadrons and their semi-leptonic decay products as a function of their relative azimuth. Modifications or even the complete absence of initially existing correlations in
Pb
+
Pb
collisions might indicate thermalization at the partonic level.
Differential triangular flow, v3(pT), of negative pions is measured at sNN=17.3 GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0–30% with a mean ...centrality of 5.5%. This is the first measurement as a function of transverse momentum of the triangular flow at SPS energies. The pT range extends from about 0.05 GeV/c to more than 2 GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydrodynamic calculation combined with an UrQMD cascade model for the late stages.
Space charge in drift chambers operated with the Xe,CO2(15%) mixture Andronic, A.; Appelshäuser, H.; Blume, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2004, Volume:
525, Issue:
3
Journal Article
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