Search results for "DAMAGE"
showing 10 items of 1289 documents
Design of large scale sensors in 180 nm CMOS process modified for radiation tolerance
2019
International audience; The last couple of years have seen the development of Depleted Monolithic Active Pixel Sensors (DMAPS) fabricated with a process modification to increase the radiation tolerance. Two large scale prototypes, Monopix with a column drain synchronous readout, and MALTA with a novel asynchronous architecture, have been fully tested and characterized both in the laboratory and in test beams. This showed that certain aspects have to be improved such as charge collection after irradiation and the output data rate. Some improvements resulting from extensive TCAD simulations were verified on a small test chip, Mini-MALTA. A detailed cluster analysis, using data from laboratory…
UV–VUV laser induced phenomena in SiO2 glass
2004
Abstract Creation and annihilation of point defects were studied for SiO2 glass exposed to ultraviolet (UV) and vacuum UV (VUV) lights to improve transparency and radiation toughness of SiO2 glass to UV–VUV laser light. Topologically disordered structure of SiO2 glass featured by the distribution of SiOSi angle is a critical factor degrading transmittance near the fundamental absorption edge. Doping with terminal functional groups enhances the structural relaxation and reduces the number of strained SiOSi bonds by breaking up the glass network without creating the color centers. Transmittance and laser toughness of SiO2 glass for F2 laser is greatly improved in fluorine-doped SiO2 glass…
Radiation hard monolithic CMOS sensors with small electrodes for High Luminosity LHC
2019
Abstract The upgrade of the tracking detectors for the High Luminosity-LHC (HL-LHC) requires the development of novel radiation hard silicon sensors. The development of Depleted Monolithic Active Pixel Sensors targets the replacement of hybrid pixel detectors with radiation hard monolithic CMOS sensors. We designed, manufactured and tested radiation hard monolithic CMOS sensors in the TowerJazz 180 nm CMOS imaging technology with small electrodes pixel designs. These designs can achieve pixel pitches well below current hybrid pixel sensors (typically 50 × 50 μ m ) for improved spatial resolution. Monolithic sensors in our design allow to reduce multiple scattering by thinning to a total si…
Results on radiation hardness of black silicon induced junction photodetectors from proton and electron radiation
2020
Abstract The stability of black silicon induced junction photodetectors under high-energy irradiation was tested with 11 MeV protons and 12 MeV electrons using fluence of 1 ⋅ 10 10 protons/cm2 and dose of 67 krad(Si) for protons and electrons, respectively. The energies and dose levels were selected to test radiation levels relevant for space applications. The degradation was evaluated through dark current and external quantum efficiency changes during (within 1 h after each step) and after (some days after) full irradiation sequences. Furthermore, the black silicon photodetectors were compared to planar silicon induced junction and planar silicon pn-junction photodetectors to assess the co…
Formation of dislocations in LiF irradiated with 3He and 4He ions
2018
Influence of the irradiation with 13.5 MeV 3He and 5 MeV 4He ions on the micro-structure and mechanical properties of LiF single crystals was studied. The depth profiles of nanoindentation, dislocation mobility, selective chemical etching and photoluminescence served for the characterization of damage. Strong ion-induced increase of hardness and decrease in dislocation mobility at the stage of track overlapping due to accumulation of dislocations and other extended defects was observed. At high fluences (1015 ions/cm2) the hardness saturates at about 3.5 GPa (twofold increase in comparison to a virgin crystal) thus confirming high efficiency of light projectiles in modifications of structur…
Silicon detectors for the sLHC
2011
In current particle physics experiments, silicon strip detectors are widely used as part of the inner tracking layers. A foreseeable large-scale application for such detectors consists of the luminosity upgrade of the Large Hadron Collider (LHC), the super-LHC or sLHC, where silicon detectors with extreme radiation hardness are required. The mission statement of the CERN RD50 Collaboration is the development of radiation-hard semiconductor devices for very high luminosity colliders. As a consequence, the aim of the RandD programme presented in this article is to develop silicon particle detectors able to operate at sLHC conditions. Research has progressed in different areas, such as defect …
In situ and postradiation analysis of mechanical stress in Al2O3:Cr induced by swift heavy-ion irradiation
2010
Abstract Optical spectroscopy and TEM techniques have been applied to study the radiation damage and correlated mechanical stresses in Al2O3 and Al2O3:Cr single crystals induced by (1–3) MeV/amu Kr, Xe and Bi ion irradiation. Mechanical stresses were evaluated in situ using a piezospectroscopic effect through the shift of the respective lines in ionoluminescence spectra. It was found that dose dependence of the stress level for Xe and Bi ions, when ionization energy loss exceeds the threshold of damage formation via electronic excitations, exhibits several alternate stages showing the build-up and relaxation of stresses. The beginning of relaxation stages is observed at fluences associated …
Radiation-hard semiconductor detectors for SuperLHC
2005
An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 10^35 cm^(- 2) s(- 1) has been envisaged to extend the physics reach of the machine. An efficient tracking down to a few centimetres from the interaction point will be required to exploit the physics potential of the upgraded LHC. As a consequence, the semiconductor detectors close to the interaction region will receive severe doses of fast hadron irradiation and the inner tracker detectors will need to survive fast hadron fluences of up to above 1016 cm 2. The CERN-RD50 project ''Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders'' has been established in 2002 to explore…
A gas ionisation Direct-STIM detector for MeV ion microscopy
2015
Abstract Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Muller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors …
The Pion Single-Event Effect Resonance and its Impact in an Accelerator Environment
2020
International audience; The pion resonance in the nuclear reaction cross section is seen to have a direct impact on the single-event effect (SEE) cross section of modern electronic devices. This was experimentally observed for single-event upsets and single-event latchup. Rectangular parallelepiped (RPP) models built to fit proton data confirm the existence of the pion SEE cross-section resonance. The impact on current radiation hardness assurance (RHA) soft error rate (SER) predictions is, however, minimal for the accelerator environment since this is dominated by high neutron fluxes. The resonance is not seen to have a major impact on the high-energy hadron equivalence approximation estab…