The basics of radiation damage in crystalline silicon networks by NIEL

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Carla Daruich de Souza ◽  
Jin Joo Kim ◽  
Jin Tae Hong
Keyword(s):  
Radiation Damage ◽  
Measurement Errors ◽  
Nuclear Reactor ◽  
Crystalline Silicon ◽  
Radiation Detectors ◽  
Crystalline Lattice ◽  
Permanent Damage ◽  
Silicon Materials

Basically, radiation can cause two effects on materials: ionization and non-ionization. This work presented the theory involved in defects caused by non-ionization, known as NIEL, with a focus on silicon materials. When energy is transferred directly to the atoms in the crystalline lattice, it can either be dissipated in the form of vibrations or be large enough to pull atoms out of that lattice. This weakens the lattice, causing measurement errors that can lead to permanent damage. This study is extremely important because silicon materials are used in radiation detectors. These detectors cannot return false measurements, especially in dangerous situations, such as in nuclear reactor monitoring. After presenting the theory involved, examples are shown. Failures of up to 30% were found by the researchers.

Neutron Radiation Effects on Lubricants and O-Rings for Target and Accelerator Applications

2021 ◽  
Vol 1024 ◽  
pp. 127-133
Author(s):  
Matteo Ferrari ◽  
Aldo Zenoni ◽  
Yong Joong Lee ◽  
Alberto Andrighetto
Keyword(s):  
Gamma Radiation ◽  
Radiation Damage ◽  
Radiation Effects ◽  
Nuclear Reactor ◽  
Neutron Radiation ◽  
Radioactive Isotopes ◽  
Structural Level ◽  
Radiation Resistant ◽  
Under Construction ◽  
Neutron Radiation Effects

Lubricants and O-rings are necessarily used for the construction of many accelerator-driven facilities as spallation sources or facilities for the production of radioactive isotopes. During operation, such component will absorb high doses of mixed neutron and gamma radiation, that can degrade their mechanical and structural properties. Experimental radiation damage tests of these components are mandatory for the construction of the facility. Methodologies for irradiation in nuclear reactor mixed fields and post-irradiation examination of lubricating oils, greases and O-rings were developed and are here presented. Samples were characterized with standard mechanical and physical-chemical tests. Parametric studies on the dose rate effects have been performed on O-rings. A case studies for a specific O-ring application in a gate valve has been developed. Some of the tested samples showed a dramatic change of their properties with dose, while others remain stable. Results were collected on nine commercial greases, on one oil and on four commercial elastomeric O-rings. The most radiation resistant among the selected products are now considered for application in facilities under construction. The main mechanisms of neutron and gamma radiation damage on these polymers were investigated at the mechanical and structural level.

Nonequilibrium processes for generating silicon nanostructures in single-crystalline silicon

2002 ◽  
Vol 74 (9) ◽  
pp. 1631-1641 ◽  
Author(s):  
P. Sen ◽  
J. Akhtar
Keyword(s):  
Vibrational Energy ◽  
Crystalline Silicon ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Crystalline Lattice ◽  
Periodic Lattice ◽  
Silicon Nanostructures ◽  
Nonlinear Transport ◽  
Single Crystalline

The possibility of modifying existing materials through technology has become the recipe for preparation of advanced materials. Nonequilibrium processing of silicon through MeV ion irradiation will be shown here to yield interesting properties. We propose localization of vibrational energy following an ion irradiation process and their transport (nonlinear transport of energy) through linear chains of a single-crystalline lattice. The localization of energy can involve 3­4 atoms, and, hence, nanometer-sized entities evolve, distinguishable from the remaining periodic lattice owing to their unique interatomic distances. The energy required to produce these structures is supplied by a single high-energy heavy ion, incident normal to a suitable crystal face so as to lose energy by the electronic energy loss mechanism. These entities can be trapped at a desired location that leads to silicon nanostructures with modified band-gaps.

Influence of hydrogen concentration on void-related microstructure in low hydrogen amorphous and crystalline silicon materials

2014 ◽  
Vol 92 (7/8) ◽  
pp. 700-704 ◽  
Author(s):  
W. Beyer ◽  
U. Breuer ◽  
R. Carius ◽  
W. Hilgers ◽  
D. Lennartz ◽  
...  
Keyword(s):  
Hydrogen Concentration ◽  
Amorphous Materials ◽  
Low Dose ◽  
Concentration Level ◽  
Crystalline Silicon ◽  
High Deposition Temperature ◽  
Diffusion Paths ◽  
Silicon Materials ◽  
Amorphous Si ◽  
Hydrogenated Amorphous

The influence of implanted hydrogen (up to a concentration level of 3 at. %) on the microstructure of silicon (Si) materials is investigated by Fourier transform infrared spectroscopy as well as by effusion of hydrogen and of (low dose) implanted helium. Three materials of low original hydrogen concentration, crystalline Si, electron beam evaporated amorphous Si, and plasma-deposited hydrogenated amorphous Si (using high deposition temperature) were investigated. Significant differences between crystalline and amorphous materials were observed. In crystalline Si, implanted hydrogen is found to generate multivacancies that trap diffusing helium while this is not the case in amorphous Si. Accordingly, cavities where hydrogen is located in amorphous Si must be smaller than divacancies. Those cavities in amorphous Si, present from the growth process, that trap helium tend to disappear when the implanted hydrogen concentration increases. Annealing of the materials up to temperatures of 575 °C was also studied. No significant change in the density of voids (trapping helium) occur but in case of crystalline Si the bonding sites of hydrogen as well as the diffusion paths of helium change.

Infrared light emission due to radiation damage in crystalline silicon

1997 ◽  
Vol 101 (12) ◽  
pp. 889-891
Author(s):  
D. Bisero ◽  
F. Corni ◽  
G. Ottaviani ◽  
R. Tonini ◽  
L. Pavesi
Keyword(s):  
Radiation Damage ◽  
Light Emission ◽  
Crystalline Silicon ◽  
Infrared Light

Bulk Defects and Radiation Damage in Detector Grade Silicon

1993 ◽  
Vol 302 ◽  
Author(s):  
J. Walter ◽  
W. Garber ◽  
R. Wunstorf ◽  
W. Bugg ◽  
J. Harvey ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Point Defects ◽  
Deep Level ◽  
Radiation Detectors ◽  
Impurity Density ◽  
Neutron Damage ◽  
Current State ◽  
Neutron Transmutation ◽  
Grade Silicon ◽  
Induced Changes

ABSTRACTThe importance of bulk defects in Si to the performance of Si radiation detectors is discussed and the current state of knowledge about deep level defects, including those induced by radiation damage, is briefly reviewed. The importance and origins of the fluctuations in the spatial distribution of the shallow point defects which determine the uncompensated net impurity density are discussed and information on this problem in FZ silicon, multipass FZ silicon, neutron transmutation doped Si, and radiation damaged Si is presented and compared to what should be expected on the basis of simple modeling. A new model for radiation damage induced changes in the net uncompensated impurity density is reviewed and compared to experimental data on fast neutron damage in Si.

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