The study of nuclear fragmentation plays a central role in many important applications: from the study of Particle Therapy (PT) up to radiation protection for space (RPS) missions and the design of ...shielding for nuclear reactors. The FragmentatiOn Of Target (FOOT) collaboration aims to study the nuclear reactions that describe the interactions with matter of different light ions (like
H
1
,
H
e
4
,
C
12
,
O
16
) of interest for such applications, performing double differential fragmentation cross section measurements in the energy range of interest for PT and RPS. In this manuscript, we present the analysis of the data collected in the interactions of an oxygen ion beam of 400 MeV/u with a graphite target using a partial FOOT setup, at the GSI Helmholtz Center for Heavy Ion Research facility in Darmstadt. During the data taking the magnets, the silicon trackers and the calorimeter foreseen in the final FOOT setup were not yet available, and hence precise measurements of the fragments kinetic energy, momentum and mass were not possible. However, using the FOOT scintillator detectors for the time of flight (TOF) and energy loss (Δ
E
) measurements together with a drift chamber, used as beam monitor, it was possible to measure the elemental fragmentation cross sections. The reduced detector set-up and the limited available statistics allowed anyway to obtain relevant results, providing statistically significant measurements of cross sections eagerly needed for PT and RPS applications. Whenever possible the obtained results have been compared with existing measurements helping in discriminating between conflicting results in the literature and demonstrating at the same time the proper functioning of the FOOT ΔE-TOF system. Finally, the obtained fragmentation cross sections are compared to the Monte Carlo predictions obtained with the FLUKA software.
Electrical properties of laser-bonded Silicon-On-Diamond samples Sciortino, S.; Brandi, F.; Carzino, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
730
Journal Article
Recenzirano
In this work we report preliminary tests aimed at the implementation of a Silicon-On-Diamond (SOD) radiation sensor. SOD materials have been prepared by continuously scanning a 20ps pulsed 355nm ...laser beam on the silicon–diamond interface. A pixel monolithic sensor has also been bonded to diamond with the same technique and tested to show that a complex electronic chip can undergo the process without any damage. Through silicon vias have been fabricated by laser drilling on the silicon side of the SOD samples and their insulation from the silicon bulk has been tested. The charge collection efficiency of a diamond sensor with laser-written graphitic contacts has been measured, to demonstrate a reliable and simple way to fabricate ohmic contacts on the diamond side of the SOD devices. Finally, a SOD material with electric contacts on the silicon and on the diamond sides has been tested as a particle sensor to demonstrate the electrical continuity of the silicon–diamond interface after the bonding.
•The steps necessary to fabricate a monolithic Silicon-On-Diamond detector have been carried out.•These steps involve the bonding, by a laser technique, of an electronic chip on diamond without damage, the growth of insulated Through Silicon Vias in silicon, the fabrication of ohmic contacts by laser graphitization.•In conclusion: the feasibility of a SOD detector with the readout silicon electronics bonded to the diamond sensitive volume has been demonstrated.•Graphitic contacts compare favorably with standard metallic ones.•Charge is collected by a SOD material. That is, the silicon–diamond bonding interface does not prevent charge collection.
Highlights • A wireless real-time dosimeter for interventional radiology has been developed. • Tested on more than 40 procedures with linear response to dose. • It records a trace of dose-rate at 5 ...Hz frequency to be used for self-training.
Pixel sensors have been calibrated using both fluorescence X-ray photons and an X-ray beam obtained by the transmission technique. The X-rays were generated by an Amptek EDIX 40 X-ray tube (maximum ...voltage 40kV). During the fluorescence calibration the pixel sensor was placed in front of the target in an off-beam position; the resulting photons hitting the detector were emitted by fluorescence in all directions with an energy which is typical of the fluorescence lines of the target material. During the calibration in the transmission mode the detector was placed behind the target, acting now as a filter, and the energy of the photons was tuned by adjusting the voltage of the tube and the thickness of the target. In this paper the comparison between the two methods will be shown. From the results of this test, it is possible to infer that transmission is more efficient (higher photon yield) and flexible (more energy points are possible) but produces broader spectral lines while fluorescence has a better energy definition. A reasonable strategy to benefit from both methods is using fluorescence to calibrate a spectrometer that will be used to evaluate the energy of the X-rays emitted in the transmission mode. The results of this calibration will be shown in this paper.
The Interventional Radiology (IR) is a well established technique in medical domain aiming to obtain a good X-ray image quality while minimizing the radiation dose absorbed by patients and staff ...members. From a radioprotection point of view, these procedures are considered potentially harmful for interventional radiologists and medical staff. Individual monitoring of operators is very important and is performed by assessing effective dose, equivalent dose to the extremities and eye lens, with the use of passive dosimeters (e.g. TLDs) calibrated in terms of personal dose equivalent
H
p
(10),
H
p
(0.07) and
H
p
(3), respectively.
In this work we will present a proposal for an innovative X-ray dosimeter prototype, capable of real-time measurements, packaged in a small form-factor, with wireless communication to be used for individual operators dosimetry during IR procedures. The proposed real-time dosimeter relies on CMOS Active Pixel Sensor, widely used in visible imaging applications. Some preliminary results on the characterization of CMOS active pixel sensors as diffused X-ray detectors during a typical IR session will be presented.
► We present a proposal for an innovative X-ray dosimeter capable of real-time measurements. ► The sensor part is based on CMOS pixel imagers. ► A wireless communication system will be used to monitor in real-time each operator. ► Preliminary results obtained in typical IR conditions will be presented.
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