The imaging performance of a phosphor-coated CCD system for mammography application is evaluated. The coated CCD is obtained by direct deposition of a Gd
2O
2S:Eu powder onto a detector surface. ...Modulation transfer function, noise power spectrum, and detective quantum efficiency are measured. Their dependence on the input beam X-ray energy is discussed. Images of a test phantom for mammography are compared with those obtained with a screen-film combination.
The ELI-NP Gamma Beam System will deliver an intense gamma beam, in an energy range from 1 to 20 MeV, with unprecedented specifications in terms of brilliance, photon flux and energy bandwidth. A ...characterization system providing a measurement of the energy spectrum, intensity, space and time profile of the beam is essential for the commissioning and the development of the source, as well as to demonstrate the performance achieved. The technical specifications of the gamma beam prevents to use any traditional gamma spectroscopic detector. A specific system equipped with four basic elements is under development: a sampling calorimeter, for a fast combined measurement of the beam average energy and intensity; a Compton spectrometer, for photon energy spectrum measuring and monitoring; a nuclear resonant scattering spectrometer, for an absolute beam energy calibration and a beam profile imager to be used for alignment and diagnostics purposes. An overview of the ELI-NP gamma characterization system will be given in this work, with a focus on the calorimeter working principle, its expected performances and some preliminary prototype tests.
Autoradiography with silicon strip detectors Bertolucci, E.; Conti, M.; Grossi, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/1996, Volume:
381, Issue:
2
Journal Article
Peer reviewed
A digital autoradiography system based on double sided silicon strip detectors (1.6 × 1.6 mm
2 active surface with 100 μm pitch) has been developed and successfully tested with beta-emitting tracers. ...It is shown here that the system is able to perform imaging of organic material with specific sensitivity as small as 0.002 nCi/mm
2, and to record activity measurements with good linearity in the range 0.002–20 nCi/mm
2. Autoradiographic images of clusters of mammary cells marked with ortho-(
32P)phosphate, obtained with an exposure time of about 10 min are presented.
High frequencies in the microwave spectrum are nowadays no more just confined to telemetry and remote sensing applications. Electromagnetic propagation at frequencies above 6 GHz for ICT end-user ...application is quickly becoming a reality opening the door to the world of millimeter and sub-millimeter wavelengths. Due to the high frequencies and large bandwidths requested for new devices, the design of the communication links to grant the appropriate service is now critical, especially for Satellite to Earth links. Evolution of the weather forecast models into 3D High Resolution meteorological parameters prediction systems represent a new kick-off for prediction of electromagnetic signals behaviour through the atmosphere, to be used alongside the already consolidated statistical approach. Different weather forecast models are applied to calculate estimation of various parameters focusing on excess attenuation and refraction index structure constant. The results show the goodness of this approach, especially when paired with the GFS weather forecast model. From results analysis of a case-study, the stratification of the atmosphere also lead to small difference when considering the signal path from the geosynchronous satellite on a real slant or just on pseudo-slant due to quite high elevation angle of receiving station antenna. This solution, compared to the statistical one, has the advantage to give a time series prediction of the electromagnetic signal behaviour and not just a statistical value or worst case to refer at. The quality of the results suggests the possibility of a future application of this approach to the solution of critical link budgets or to predict signal attitude during severe atmosphere events helping prevent out of service time of ICT systems.
A prototype instrument is presented for the indirect evaluation of the main physical parameters characterizing a mammographic x-ray beam. The instrument consists of an x-ray probe with four filtered ...solid-state detectors connected to a signal-conditioning electronic circuitry and a high-speed digitizer interfaced to a portable personal computer. The system, governed by an ad hoc developed software, can measure kVp, kV waveform, ripple, HVL, exposure time and exposure in a single shot of the x-ray beam with good accuracy. The system should prove very useful to any quality-control programme for mammography.
Hard X-ray (>15 keV) experiments for space astronomy require a detailed energy calibration in order to determine their true response matrix. To this end, an X-ray facility is built based on the use ...of a very stable X-ray generator plus an X-ray goniometer for crystal diffraction, that can provide collimated and monochromatic photons with energies in the range from about 15 keV to about 140 keV. A description is presented of the facility and its performance. The facility is used to test samples of hard X-ray mirrors for space astronomy, and it is being equipped to calibrate the high-energy experiment PDS on board the X-ray astronomy satellite SAX.< >
Double-sided microstrip silicon crystals are tested as detectors for X-rays in the diagnostic energy range (10-100 keV) for digital radiography. An analog-to-digital converter (ADC) and CAMAC-based ...acquisition system is developed to study the imaging capabilities of a silicon mu strip detector with 100- and 200- mu m read-out pitch. The first images of submillimeter high contrast phantoms obtained with an X-ray mammography tube operating at high flux density are presented.< >
The purpose of this two-part study was to conduct a social validation assessment of microswitches versus interaction/stimulation conditions used with persons with multiple disabilities. In Part I, 32 ...teacher-assistant trainees were shown video-tapes reporting the use of microswitches versus interaction conditions for six children. In Part II, 40 teacher-assistant trainees or classroom aides and 44 rehabilitation staff were presented with video-tapes showing the use of microswitches versus systematic stimulation strategies for four adults. Raters scored the microswitch and the interaction or stimulation conditions on a 7-item questionnaire covering social/emotional and practical aspects. The microswitch condition was viewed as generally more positive than or comparable to the interaction or stimulation conditions. Main features of the findings and their implications are discussed.
A radiation probe was designed for indirectly determining the high voltage of a Mo anode mammography unit. The real time processing of the probe outputs yields exposure time, voltage waveform, kVp, ...and ripple in the range 24-40 kVp useful for screen-film mammography. The probe, connected to a portable computer, will be employed in a survey of radiation dose and image quality in mammography as part of an ongoing program in Italy.
