A new batch of microdosimeters has been extensively studied for their charge collection efficiency (CCE) properties, as well as their radiation hardness for medical, space and accident applications. ...Silicon-on-insulator (SOI) microdosimeters with an active layer thickness of 10, 20 and 50 μm have been investigated and were characterized with a 24 MeV carbon ion beam as well as a Co-60 gamma source. A negative pulse was observed in addition to the positive pulses generated within the sensitive volumes (SVs) by incident ions which led to undesirable low energy events in the SOI microdosimeters response. To study this phenomenon, the microdosimeters were irradiated with gamma radiation from a Co-60 source with a total dose of 3 and 10 Mrad(Si). It was determined that the negative pulse was originating from the support wafer due to the displacement current phenomenon. Irradiation with the Co-60 source led to a disappearing of the negative pulse due to an increase in recombination within the support wafer while almost no changes in CCE were observed. A radiation hardness study was also performed on the 50 μm SOI microdosimeter with 16 SVs being irradiated with a fluence of ~ 10 8 12 C ions/cm 2 . A CCE deficit of approximately 2% was observed at an operation bias of 10V within the SVs. The findings of this work demonstrate that the SOI microdosimeters can be utilized in space and medical applications as they can handle typical levels of dose encountered in these applications. Additionally, evidence for SOI microdosimeter fabrication standards in terms of support wafer resistivity and buried oxide (BOX) thickness is shown.
Radiation monitoring in space radiation is complex due to galactic cosmic rays (GCRs), solar particle events (SPEs), and albedo particles. Thermal neutrons are an important component in the Moon ...radiation albedo field which can cause single event upset (SEU) in electronics when they interact with the 10 B present in electronic components. In this work, we studied an application of silicon on insulator (SOI) microdosimeters for neutron monitoring in various mixed radiation field environments. A 10-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> SOI microdosimeter was utilized in conjunction with a 10 B 4 C thin-film converter to successfully measure the thermal neutron contribution out of field of a therapeutic proton beam as well as an 18-MV X-ray linear accelerator (LINAC). The microdosimeter was placed downstream of the Bragg peak (BP) as well as laterally out of field of the proton beam and at two positions along the treatment couch of the 18-MV LINAC. It was demonstrated that the 10-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> SOI microdosimeter with 10 B 4 C converter is suitable for detection of thermal neutrons with excellent discrimination of gamma, fast and thermal neutron components in the presence of a gamma-neutron pulsed field of an 18-MV LINAC. To reduce the gamma contribution and further improve detection of neutrons in mixed radiation fields, a new <inline-formula> <tex-math notation="LaTeX">2 ~\mu \text{m} </tex-math></inline-formula> Mushroom-planar microdosimeter was fabricated and characterized in detail using an ion beam induced charge collection (IBIC) technique with 1.78 MeV <inline-formula> <tex-math notation="LaTeX">\text{H}e^{\mathrm {2+}} </tex-math></inline-formula> ions. It was demonstrated that this <inline-formula> <tex-math notation="LaTeX">2 ~\mu \text{m} </tex-math></inline-formula> SOI microdosimeter can be operated in a passive mode. The SOI microdosimeter with the 10 B 4 C converter can be recommended for the detection of thermal neutrons for SEU prediction in the mixed gamma-neutron fields during space missions, especially for the Moon mission.
This article presents a study of the response of the silicon on insulator (SOI) microdosimeter with 3-D sensitive volumes (SVs) to 400 MeV/u 16 O and 500 MeV/u 56 Fe ions mimicking galactic cosmic ...rays outside and inside the International Space Station (ISS). An average quality factor (Q̅) and the dose equivalent (H) of the radiation field were obtained experimentally, and the results were compared with GEANT4 simulations.
Development of planar detectors with active edge Povoli, M.; Bagolini, A.; Boscardin, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2011, Letnik:
658, Številka:
1
Journal Article
Recenzirano
We report on the first batch of planar active edge sensors fabricated at Fondazione Bruno Kessler (Trento, Italy) on the way to the development of full 3D detectors with active edges. The main design ...and technological aspects are reported, along with selected results from the electrical characterization of detectors and test structures.
We report on experimental results and TCAD simulations addressing the impact of layout on the electrical characteristics of double-sided 3D diodes fabricated at Fondazione Bruno Kessler (FBK), ...Trento, Italy. Simulations are found to accurately reproduce the device characteristics, thus explaining the basic mechanisms governing the breakdown behavior and capacitance of different devices and providing useful hints for layout optimization.
Characterization of 3D-DDTC strip sensors with passing-through columns Povoli, M.; Betancourt, C.; Boscardin, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
730
Journal Article
Recenzirano
We report on the pre-irradiation electrical and functional characterization of newly developed 3D silicon strip detectors fabricated at FBK. Critical layout aspects present in the previous version of ...the technology were solved, and the new sensors are showing encouraging results both in terms of electrical properties and charge collection efficiency.
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