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C Carpentieri,
M G Bisogni,
A Del Guerra,
P Delogu,
M E Fantacci,
J Fogli,
A Marchi, V Marzulli,
V Rosso,
A Stefanini,
A Tofani
[show abstract]
[hide abstract]
ABSTRACT: Recent advances in semiconductor pixel detectors and read-out electronics allowed to build the first prototypes of single photon-counting imaging systems that represent the last frontier of digital radiography. Among the advantages with respect to commercially available digital imaging systems, there are direct conversion of photon energy into electrical charge and the effective rejection of electronic noise by means of a thresholding process. These features allow the photon-counting systems to achieve high imaging performances in terms of spatial and contrast resolution. Moreover, the now available deep integration techniques allow the reduction of the pixel size and the improvement of the functionality of the single cell and the read-out speed so as to cope with the high fluxes found in diagnostic radiology. In particular, the single photon-counting system presented in this paper is based on a 300-microm thick silicon pixel detector bump-bonded to the Medipix2 read-out chip to form an assembly of 256 x 256 square pixels at a pitch of 55 microm. Each cell comprises a low-noise preamplifier, two pulse height discriminators and a 14-bit counter. The maximum counting rate per pixel is 1 MHz. The chip can operate in two modalities: it records the events with energy above a threshold (single mode) or between two energy thresholds (window mode). Exploiting this latter feature, a possible application of such a system as a fast spectrometer is presented to study the energy spectrum of diagnostic beams produced by X-ray tubes.
Radiation Protection Dosimetry 06/2008; 129(1-3):119-22. · 0.82 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The work presented here was developed in the framework of the SENTINEL Project and is devoted to the analysis of dental radiology dosimetric data. The procedure of data processing allows the analysis of some important aspects related to the protection of the patient and the staff because of the position of the operators near the patient and their exposure to the radiation scattered by the patient. Dental radiology data was collected in an Italian hospital. Following the Italian quality assurance (QA) protocols and suggestions by the leaders of the SENTINEL Project, X-ray equipment performances have been analysed in terms of: kVp accuracy, exposure time accuracy and precision, tube output, dose reproducibility and linearity, beam collimation, artefacts and light tightness. Referring to these parameters the physical quality index (QI) was analysed. In a single numerical value between 0 and 1, QI summarises the results of quality tests for radiological devices. The actual impact of such a figure (as suggested by international QA protocols or as adopted by local QA routine) on the policy of machine maintenance and replacement is discussed.
Radiation Protection Dosimetry 04/2008; 129(1-3):227-30. · 0.82 Impact Factor
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V. Fanti,
A. Lai,
D Marras,
L. Musa,
B Hay,
K N Moore,
G Barr,
H. Blumer,
G Bocquet,
J Bremer, [......],
G. Wirrer,
A. Gaponenko,
V Kekelidze,
D Madigojine,
A Mestvirishvili,
N Molokanova,
Yu. Potrebenikov,
G. Tatishvili,
A. Tkatchev,
A Zinchenko
[show abstract]
[hide abstract]
ABSTRACT: . A new precision measurement of the # 0 mass has been performed at the NA48 experiment at the CERN SPS. The value obtained is [1314.820.06 (stat.) 0.2 (syst.)] MeV/c 2 . The branching ratios of # 0 radiative decays have been measured as: Br(# 0 # ##)=[1.90 0.34(stat.) 0.19(syst.)] 10 -3 and Br(# 0 # # 0 #)=[3.14 0.76(stat.) 0.32(syst.)] 10 -3 . The NA48 Collaboration: Precision measurement of the # 0 mass 1 Introduction A precise measurement of hyperon masses permits the checking of the mass splitting related to radiative corrections. The mass of the # 0 hyperon is known with less pre- a Present address: Dipartimento di Fisica dell'Universitae Sezione dell'INFN di Perugia, 06100 Perugia, Italy. b Present address: Physics-Astronomy Building, Michigan State University, East Lansing, MI 48824 USA. c Present address: NIKHEF, PO Box 41882,1009 DB Amsterdam, The Netherlands. d Funded by the UK Particle Physics and Astronomy Research Council....
06/2000;
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S.R. Amendolia,
A. Barsotti,
A.M. Calafiore,
M.G. Bisogni,
U. Bottigli,
M.A. Ciocci,
P. Delogu,
M.E. Fantacci, V. Marzulli,
P. Maestro,
E. Pernigotti,
N. Romeo,
V. Rosso,
A. Samaritani,
A. Stefanini,
S. Stumbo
[show abstract]
[hide abstract]
ABSTRACT: The left ventricular reduction called Batista's procedure (BP) is
a surgical technique able to improve the ventricular function in the
heart disease known as Congestive Heart Failure (CHF). From a
geometrical point of view the BP is a restyling of the left ventricle
from a spherical configuration to an ellipsoidal one. The authors have
written a program (“SoftHeart”) which simulates the response
of the heart after the BP. The main products of the authors' program are
the new ejection fraction and the new stroke volume as a function of the
equatorial surgical reduction. Using these curves it is possible to
classify the patients into three categories corresponding to a
Gaussian-like curve, a flat curve and a monotonic descending curve,
respectively. A clinical trial performed on 165 patients allows a good
correlation between the three categories built by
“SoftHeart” and three different clinical situations. An
explanation of the three categories produced by “SoftHeart”
using the Laplace and the Frank-Starling laws is reported
Computers in Cardiology 1998; 10/1998
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G.D. Barr,
C. Bruschini,
G Bocquet,
P. Buchholz,
D. Cundy,
N Doble,
W Funk,
L Gatignon,
A Gonidec,
B. Hallgren, [......],
A Givernaud,
L Gosset,
J Heitzmann,
E Mazzucato,
B Peyaud,
R Turlay,
C Biino,
A Ceccucci,
P Maas,
S Palestini
[show abstract]
[hide abstract]
ABSTRACT: The NA48 collaboration is preparing a new experiment at CERN aiming to study CP violation in the K #K system with an accuracy of 2 10 #4 in the parameter 0 ###. Decays into two # #s will be recorded by a quasi#homogeneous liquid krypton calorimeter. A liquid krypton calorimeter has been chosen to combine good energy# position and time resolution with precise charge calibration and long#term stability. The prototype calorime# ter incorporating the #nal design of the electrode read#out structure is presented in this paper. An energy resolution of 3#5# p E with a constant term smaller than 0#5# has been obtained. The time resolution was found to be better than 300 ps above 15 GeV.
07/1998;
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V Fanti,
A Lai,
L Musa,
A Nappi,
M G Setzu,
R W Moore,
D J Munday,
M A Parker,
S F Takach,
T O White, [......],
P Maas,
F Marchetto,
E Menichetti,
H Dibon,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok
[show abstract]
[hide abstract]
ABSTRACT: The rate of the decay of the neutral K meson into KL 0 → μμγ has been measured with the NA48 detector at the CERN SPS. A total of 59 events has been observed with an estimated background of 14 events. The overall Kaon flux was determined to be 1.2 × 109. This observation corresponds to a branching ratio of (3.4 ± 0.6stat ± 0.4sys) × 10-7. Using this branching ratio the parameter αK* describing the relative strength of the two contributing amplitudes to this decay, through intermediate pseudoscalar or vector-like mesons, was measured to be αK*= -0.04-0.21+0.24. © Springer-Verlag 1997.
Zeitschrift fur Physik C-Particles and Fields. 01/1997; 76(4):653-657.
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C. Avanzini,
F. Costantini,
F. Fidecaro,
B. Gorini,
F. Laico,
G. Magazzu, V. Marzulli,
F. Morasni,
D. Passuello,
G. Pierazzini,
R. Tripiccione,
F. Rossi
[show abstract]
[hide abstract]
ABSTRACT: The PeakSum Processing System (PSS) is an element of the neutral
trigger of the NA48 experiment at CERN. The PSS is a pipelined processor
based on a VLSI semi-custom device, containing all the processing blocks
needed in the system. The PSS provides information on the energy pattern
released in the electromagnetic calorimeter of the NA48 experiment, used
to identify
K<sub>0</sub>⇒π<sup>0</sup>π<sup>0</sup>⇒4γ decays
IEEE Transactions on Nuclear Science 07/1996; · 1.45 Impact Factor
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A. Kreutz,
M. Holder,
M. Rost,
R. Werthenbach,
K. J. Peach,
H. Blümer,
R. Heinz,
K. Kleinknecht,
P. Mayer,
B. Panzer, [......],
A. Bigi,
P. Calafiura,
M. Calvetti,
R. Carosi,
R. Casali,
C. Cerri,
I. Mannelli, V. Marzulli,
A. Nappi,
G. M. Pierazzini
[show abstract]
[hide abstract]
ABSTRACT: Improved branching ratios were measured for theK
LG(KL ® 3p0 )/G(KL ® p+ p- p0 ) = 1.611 ±0.037\Gamma ({\rm K}_L \to 3\pi ^0 )/\Gamma ({\rm K}_L \to \pi ^ + \pi ^ - \pi ^0 ) = 1.611 \pm 0.037
and
G(KL ® 3p0 )/G(KL ® pev) = 0.545 ±0.010.\Gamma ({\rm K}_L \to 3\pi ^0 )/\Gamma ({\rm K}_L \to \pi ev) = 0.545 \pm 0.010.
From the first number an upper limit for I=5/2 and I=7/2 transitions in neutral kaon decay is derived. Using older results for the Ke3/K3 fraction, the 30 branching ratio is found to be(K
L
30)/
tot
=(0.2110.003), about a factor three more precise than from previous experiments.
Zeitschrift für Physik C 02/1995; 65(1):67-74.
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A Kreutz,
M Holder,
M Rost,
R Werthenbach,
K J Peach,
H. Blümer,
R Heinz,
K Kleinknecht,
P Mayer,
B Panzer, [......],
A Bigi,
P. Calafiura,
M Calvetti,
R Carosi,
R Casali,
C Cerri,
I Mannelli, V. Marzulli,
A Nappi,
G M Pierazzini
[show abstract]
[hide abstract]
ABSTRACT: Improved branching ratios were measured for the $K_L \to 3 \pi^0 $ decay in a neutral beam at the CERN SPS with the NA31 detector: $\Gamma (K_L \to 3 \pi^0) / \Gamma (K_L \to \pi^+ \pi^- \pi^0) = 1.611 \pm 0.037$ and $\Gamma (K_L \to 3 \pi^0) / \Gamma (K_L \to \pi e \nu ) = 0.545 \pm 0.010$. From the first number an upper limit for $\Delta I =5/2$ and $\Delta I = 7/2 $ transitions in neutral kaon decay is derived. Using older results for the Ke3/K$\mu $3 fraction, the 3$\pi^0$ branching ratio is found to be $\Gamma (K_L \to 3 \pi^0 )/ \Gamma_{tot} = (0.211 \pm 0.003)$, about a factor three more precise than from previous experiments.
09/1994;
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V. Fanti,
A. Lai,
D. Marras,
L. Musa,
A.J. Bevan,
T.J. Gershon,
B. Hay,
R.W. Moore,
K.N. Moore,
D.J. Munday, [......],
W. Wislicki,
S. Wronka,
H. Dibon,
G. Fischer,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
M. Pernicka,
A. Taurok
[show abstract]
[hide abstract]
ABSTRACT: The NA48 experiment at CERN has performed a new measurement of direct CP violation, based on data taken in 1997 by simultaneously collecting KL and KS decays into π0π0 and π+π−. The result for the CP violating parameter is (18.5±4.5(stat)±5.8(syst))×10−4.
Physics Letters B.
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S.R Amendolia,
E Bertolucci,
M.G Bisogni,
U Bottigli,
A Ceccopieri,
M.A Ciocci,
M Conti,
P Delogu,
M.E Fantacci,
P Maestro, V Marzulli,
E Pernigotti,
N Romeo,
V Rosso,
P Rosso,
A Stefanini,
S Stumbo
[show abstract]
[hide abstract]
ABSTRACT: A GaAs pixel detector designed for digital mammography, equipped with a 36-channel single photon counting discrete read-out electronics, was tested using a test object developed for quality control purposes in mammography. Each pixel was 200×200 μm2 large, and 200 μm deep.The choice of GaAs with respect to silicon (largely used in other applications and with a more established technique) has been made because of the much better detection efficiency at mammographic energies, combined with a very good charge collection efficiency achieved thanks to new ohmic contacts. This GaAs detector is able to perform a measurement of low-contrast details, with minimum contrast lower (nearly a factor two) than that typically achievable with standard mammographic film+screen systems in the same conditions of clinical routine. This should allow for an earlier diagnosis of breast tumour masses.Due to these encouraging results, the next step in the evolution of our imaging system based on GaAs detectors has been the development of a VLSI front-end prototype chip (MEDIPIX ) in order to cover a much larger diagnostic area. The chip reads 64×64 channels in single photon counting mode, each one 170 μm wide. Each channel contains also a test input where a signal can be simulated, injecting a known charge through a 16 f F capacitor. Fake signals have been injected via the test input measuring and equalizing minimum thresholds for all the channels.On an average, in most of the performing chips available up to now, we have found that it is possible to set a threshold as low as 1800 electrons with an RMS of 150 electrons (10 standard deviations lower than the 20 keV photon signal roughly equivalent to 4500 electrons). The detector, bump-bonded to the chip, will be tested and a ladder of detectors will be prepared to be able to scan large surface objects.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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M Bender,
I Augustin,
M Holder,
I Schwarze,
M Ziolkowski,
V Fanti,
A Lai,
L Musa,
A Nappi,
M.G Setzu, [......],
P Maas,
F Marchetto,
E Menichetti,
H Dibon,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok
[show abstract]
[hide abstract]
ABSTRACT: In a preliminary version of the NA48 experiment at the CERN SPS, in which an iron-scintillator sandwich calorimeter was used as a photon detector, the ratio of KL→πμνγ and KL→πμν decays was measured. The branching ratio BR(K)/(KL→πμν) is found to be (2.08±0.17 +0.16−0.21)×10−3, where the first error is statistical and the second systematic. The result is in agreement with theoretical predictions.
Physics Letters B.
-
S.R Amendolia,
E Bertolucci,
M.G Bisogni,
U Bottigli,
M.A Ciocci,
M Conti,
P Delogu,
M.E Fantacci,
P Maestro, V Marzulli,
E Pernigotti,
N Romeo,
V Rosso,
P Russo,
A Stefanini,
S Stumbo
[show abstract]
[hide abstract]
ABSTRACT: We have investigated the detection performance of GaAs detectors made with different thickness and contact geometries. A comparison is made between these detection capabilities and the imaging requirements for the following medical applications: digital mammography, digital chest radiography and nuclear medicine. Experimental results and preliminary images are presented and discussed.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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V. Fanti,
A. Lai,
L. Musa,
D. Marras,
A. Nappi,
B. Hay,
R.W. Moore,
K.N. Moore,
D.J. Munday,
M.D. Needham, [......],
M. Szleper,
W. Wislicki,
S. Wronka,
H. Dibon,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
M. Pernicka,
A. Taurok
[show abstract]
[hide abstract]
ABSTRACT: We present the results for a direct search for light gluinos through the appearance of η→3π0 with high transverse momentum in the vacuum tank of the NA48 experiment at CERN. We find one event within a lifetime range of 10−9–10−3 s and another one between 10−10–10−9 s. Both events are consistent with the expected background from neutrons in the beam, produced by 450 GeV protons impinging on the Be targets, which interact with the residual air in the tank. From these data we give limits on the production of the hypothetical bound state, the R0 hadron, and its decay in the R0 mass range between 1 and 5 GeV.
Physics Letters B.
-
G.D. Barr,
C. Bruschini,
C. Bocquet,
P. Buchholz,
D. Cundy,
N. Doble,
W. Funk,
L. Gatignon,
A. Gonidec,
B. Hallgren, [......],
A. Givernaud,
L. Gosset,
J. Heitzmann,
E. Mazzucato,
B. Peyaud,
R. Turlay,
C. Biino,
A. Ceccucci,
P. Maas,
S. Palestini
[show abstract]
[hide abstract]
ABSTRACT: The NA48 collaboration is preparing a new experiment at CERN aiming to study CP violation in the K0- system with an accuracy of 2 × 10−4 in the parameter e(ϵ′/ϵ). Decays in two π0's will be recorded by a quasi-homogeneous liquid krypton calorimeter. A liquid krypton calorimeter has been chosen to combine good energy, position and time resolution with precise charge calibration and long-term stability. The prototype calorimeter incorporating the final design of the electrode read-out structure is presented in this paper. An energy resolution of with a constant term smaller than 0.5% has been obtained. The time resolution was found to be better than 300 ps above 15 GeV.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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V. Fanti,
A. Lai,
D Marras,
L. Musa,
A Nappi,
R Batley,
A Bevan,
R S Dosanjh,
R. Galik,
T. Gershon, [......],
S Wronka,
H Dibon,
G Fischer,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: The beam and detector, used for the NA48 experiment, devoted to the measurement of Re(ε′/ε), and for the NA48/1 experiment on rare KS and neutral hyperon decays, are described.
-
V. Fanti,
A. Lai,
L. Musa,
D Marras,
A Nappi,
B Hay,
R W Moore,
K N Moore,
D J Munday,
M D Needham, [......],
M Szleper,
W Wislicki,
S Wronka,
H Dibon,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok
[show abstract]
[hide abstract]
ABSTRACT: We present the results for a direct search for light gluinos through the appearance of $\eta\rightarrow 3\pin$ with high transverse momentum in the vacuum tank of the NA48 experiment at CERN. We find one event within a lifetime range of $10^{-9}-10^{-3}$\,s and another one between $10^{-10}-10^{-9}$\,s. Both events are consistent with the expected background from neutrons in the beam, produced by 450 GeV protons impinging on the Be targets, which interact with the residual air in the tank. From these data we give limits on the production of the hypothetical $g\widetilde{g}$ bound state, the $R^0$ hadron, and its $R^0\rightarrow\eta\photino$ decay in the $R^0$ mass range between 1 and 5~GeV.
-
V. Fanti,
A. Lai,
D. Marras,
L. Musa,
A. Nappi,
R. Batley,
A. Bevan,
R.S. Dosanjh,
R. Galik,
T. Gershon, [......],
S. Wronka,
H. Dibon,
G. Fischer,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
M. Pernicka,
A. Taurok,
L. Widhalm
[show abstract]
[hide abstract]
ABSTRACT: The beam and detector, used for the NA48 experiment, devoted to the measurement of Re(ε′/ε), and for the NA48/1 experiment on rare KS and neutral hyperon decays, are described.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
