A
bstract
The forward
η
mesons production has been observed by the Large Hadron Collider forward (LHCf) experiment in proton-proton collision at
s
= 13 TeV. This paper presents the measurement of the ...inclusive production rate of
η
in
p
T
<
1
.
1 GeV/c, expressed as a function of the Feynman-
x
variable. These results are compared with the predictions of several hadronic interaction models commonly used for the modelling of the air showers produced by ultra-high energy cosmic rays. This is both the first measurement of
η
mesons from LHCf and the first time a particle containing strange quarks has been observed in the forward region for high-energy collisions. These results will provide a powerful constraint on hadronic interaction models for the purpose of improving the understanding of the processes underlying the air showers produced in the Earth’s atmosphere by ultra-energetic cosmic rays.
Ultra-fast silicon detectors Sadrozinski, H. F.-W.; Ely, S.; Fadeyev, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
730
Journal Article
Recenzirano
Odprti dostop
We propose to develop a fast, thin silicon sensor with gain capable to concurrently measure with high precision the space (∼10μm) and time (∼10ps) coordinates of a particle. This will open up new ...application of silicon detector systems in many fields. Our analysis of detector properties indicates that it is possible to improve the timing characteristics of silicon-based tracking sensors, which already have sufficient position resolution, to achieve four-dimensional high-precision measurements. The basic sensor characteristics and the expected performance are listed, the wide field of applications are mentioned and the required R&D topics are discussed.
•We are proposing thin pixel silicon sensors with 10's of picoseconds time resolution.•Fast charge collection is coupled with internal charge multiplication.•The truly 4-D sensors will revolutionize imaging and particle counting in many applications.
A
bstract
The forward
η
mesons production has been observed by the Large Hadron Collider forward (LHCf) experiment in proton-proton collision at
$$ \sqrt{s} $$
s
= 13 TeV. This paper presents the ...measurement of the inclusive production rate of
η
in
p
T
<
1
.
1 GeV/c, expressed as a function of the Feynman-
x
variable. These results are compared with the predictions of several hadronic interaction models commonly used for the modelling of the air showers produced by ultra-high energy cosmic rays. This is both the first measurement of
η
mesons from LHCf and the first time a particle containing strange quarks has been observed in the forward region for high-energy collisions. These results will provide a powerful constraint on hadronic interaction models for the purpose of improving the understanding of the processes underlying the air showers produced in the Earth’s atmosphere by ultra-energetic cosmic rays.
Proton Computed Tomography (pCT) is a medical imaging technique based on the use of proton beams with energies above 200MeV to directly measure stopping power distributions inside the tissue volume. ...Prima (PRoton IMAging) is an Italian collaboration working on the development of a pCT scanner based on a tracker and a calorimeter to measure single protons trajectory and residual energy. The tracker is composed of four planes of silicon microstrip detectors to measure proton entry and exit positions and angles. Residual energy is measured by a calorimeter composed of YAG:Ce scintillating crystals. A first prototype of pCT scanner, with an active area of about 5×5cm2, has been constructed and characterized with 60MeV protons at the INFN Laboratori Nazionali del Sud, Catania (Italy) and with 180MeV protons at Svedberg Laboratory, Uppsala (Sweden). A new pre-clinical prototype with an extended active area up to 20×5cm2, real time data acquisition and a data rate up to 1MHz is under development. A description of the two prototypes will be presented together with first results concerning tomographic image reconstruction.
This paper describes the development of a proton Computed Tomography (pCT) apparatus able to reconstruct a map of stopping power useful for accurate proton therapy treatment planning and patient ...positioning. This system is based on two main components: a silicon microstrip tracker and a YAG:Ce crystal calorimeter. Each proton trajectory is sampled by the tracker in four points: two upstream and two downstream the object under test; the particle residual energy is measured by the calorimeter. The apparatus is described in details together with a discussion on the characterization of the hardware under proton beams with energies up to 175MeV.
Silicon carbide has a potential for solar UV radiation monitoring: extremely resistant to UV radiation damage, nearly-blind to visible and infrared radiation and less sensitive to temperature ...variations than standard radiometric systems. A radiometer composed by three SiC photodiodes has been designed, manufactured and tested under solar radiation. Two photodiodes are equipped with filters in the UVB (280–315
nm) and UVA (315–400
nm) ranges while a third is filtered to match the erythemal action spectrum. UVA, UVB components of the solar radiation as well as UV index (UVI) at the earth's surface have been determined in two site positions in Tuscany, Italy. Data as a function of day-light allowed us to evaluate total optical thickness for UVA and UVB:
τ
UVA=0.46 and
τ
UVB=1.8. UVI values measured during the year well compares with computed ones used for weather forecast procedures.
A detailed investigation of the performance as a dosimeter of state-of-art polycrystalline CVD (pCVD) diamond detectors operated in photovoltaic regime for applications in clinical radiotherapy has ...been carried out with conventional 6–10–18
MV X-photons, as well as with a 10
MV photon Intensity Modulated Radiation Therapy (IMRT) beam from a linear accelerator. Our results show that the performances of a pCVD diamond dosimeter improves dramatically when operated in null-bias conditions. Main improvements with respect to operation with an external voltage applied are: a reduced pre-irradiation dose; an excellent time stability, characterised by standard deviations less than 0.5%; a rise-time comparable to that of commercial reference dosimeters; a linearity with dose proven over three decades; a reduced deviation from linearity of the current vs. dose–rate curve, output factors comparable to that of commercial reference dosimeters. These results represent a significant step towards clinical applications as IMRT with synthetic polycrystalline CVD diamond films.
► Cr/Au metallization process on pCVD provides Schottky barrier at electrodes. ► Null-bias operation of pCVD Diamond viable solution for dosimetry. ► Null-bias operation of pCVD in radiotherapy improves their performance as dosimeters. ► Clinical applications as Intensity Modulated Radiation Therapy with pCVD diamond films.
Bidimensional silicon dosimeter: Development and characterization Talamonti, C.; Bruzzi, M.; Marrazzo, L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2011, Letnik:
658, Številka:
1
Journal Article
Recenzirano
Clinical dosimetry in radiotherapy is a well known matter but high conformal radiotherapy modalities (Intensity Modulated Radiation Therapy (IMRT), stereotactic treatments with photons and protons, ...Intensity Modulated Proton Therapy (IMPT)) possess problems due to small radiation fields with high dose gradients, variation in space and time of the dose rate and variation in space and time of the beam energy spectrum.
A modular dosimetric detector, adequate for 2D pre-treatment dose verifications, has been developed in the framework of the European Integrated project MAESTRO. The detector is a monolithic segmented sensor obtained by n-type implantation on a 50
μthick epitaxial silicon p-type layer; this is later used to guarantee improved radiation hardness of the device against the accumulated dose. The detector is composed of a matrix of 21×21 pixels with a size of 2×2
mm
2 each and a 3
mm center-to-center distance.
A full dosimetric characterization of the detector was performed with photon and proton beams and with gammas from a
60Co unit. Results have been compared with those obtained with a Farmer and a CC13 Scanditronix/Welhoffer ion chamber as well as with the silicon matrix MapCHECK™. The first application of the MAESTRO prototype in the dosimetric verification of a clinical IMRT field is also reported. Results show that our modular detector represents a valuable tool for quality assurance in IMRT dose delivery and for high precision radiotherapy techniques.
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