THE EFFECT OF CRYSTALLINITY AND BOMBARDMENT DOSE ON THE PENETRATION OF 40-keV XENON IONS IN IONIC CRYSTALS AND CERAMICS

1966 ◽  
Vol 44 (11) ◽  
pp. 2905-2914 ◽  
Author(s):  
J. L. Whitton ◽  
Hj. Matzke
Keyword(s):  
Radiation Damage ◽  
Single Crystals ◽  
Penetration Depth ◽  
Incident Beam ◽  
Ion Bombardment ◽  
Fused Silica ◽  
Ionic Crystals ◽  
Chemical Dissolution ◽  
Metal Single Crystals ◽  
Oriented Parallel

The range and depth distributions of 40-keV xenon ions in single crystals of NaCl, KBr, MgO, SiO2 (α quartz), in sintered UO2 and in fused silica, have been measured by the sectioning techniques of vibratory polishing and chemical dissolution. Channeling is observed in the single crystals when the [Formula: see text] is oriented parallel to the incident beam of the ions. This effect is similar to that previously reported for some metal single crystals. High bombardment doses produce a factor of 2–5 decrease in penetration depth in MgO and SiO2, materials which are known to be damaged by ion bombardment. This decrease is smaller in materials that do not show gross ion bombardment damage, such as NaCl, KBr, and UO2. Thus, the study of ranges is shown to be another means of detecting gross radiation damage.

scholarly journals Diffusion von Tritium in Quarz und Quarzglas

1967 ◽  
Vol 22 (6) ◽  
pp. 965-969
Author(s):  
Hj. Matzke
Keyword(s):  
Mass Transport ◽  
Diffusion Process ◽  
Radiation Damage ◽  
Volume Diffusion ◽  
Molecular Form ◽  
Ion Bombardment ◽  
Fused Silica ◽  
Kcal Mole ◽  
Crystalline Quartz ◽  
Diffusion Of Hydrogen

The release of tritium from single crystalline quartz and from fused silica has been measured following 40 keV ion bombardment to a dose of 4 × 1011 ions/cm2. The release can be explained by normal volume diffusion with D0=101±1 cm2 sec-1 for both materials and activation enthalpies of (42 ± 5) kcal/mole for quartz and (52 ± 5) kcal/mole for fused silica. Release from quartz is faster than release from fused silica. This latter diffusion process, however, is essentially slower than diffusion of hydrogen during permeation. Possible reasons for this discrepancy are the existence of radiation damage due to the ion bombardment or the chemical state of hydrogen which cause a different elementary process for mass transport: Hydrogen diffuses in molecular form during permeation whereas probably tritium atoms or ions will diffuse following ion bombardment.

Inert gas diffusion and radiation damage in ionic crystals and sinters following ion bombardment

1968 ◽  
Vol 46 (6) ◽  
pp. 621-634 ◽  
Author(s):  
Hj. Matzke
Keyword(s):  
Radiation Damage ◽  
Diffusion Mechanism ◽  
Ion Bombardment ◽  
Gas Diffusion ◽  
Absolute Temperature ◽  
Diffraction Measurement ◽  
Ionic Crystals ◽  
Rare Gases ◽  
Self Diffusion ◽  
Diffusion Phenomena

A review is given of radiation damage and diffusion phenomena in a large variety of ionic crystals (oxides and halides) and two metals following ion bombardment. Ion beams of both light and heavy nuclides between mass number 3 (tritium) and 222 (emanation) were employed. The ion doses varied between 104 and 1017 ions/cm2. Four different experimental techniques were used to detect gross structural radiation damage following bombardment: reflection electron diffraction, measurement of ranges or penetration profiles, electron microscopy in transmission or using replica techniques, and gas release measurements at low temperatures. In general, materials having cubic lattice structures were shown to be more stable than anisotropic substances.Minor local damage (such as point defects, defect clusters or voids, dislocations and loops) was studied by its interaction with rare gases or other volatile elements (Br, Rb, Cs). For the heavy rare gases (Kr, Xe, Em) and low bombardment doses, volume diffusion was observed starting between 0.4 and 0.5 of the melting point, Tm, on the absolute temperature scale. The activation enthalpies ΔH were about 80 ± 10% of those for the self-diffusion of the less mobile lattice ions and were related to Tm via ΔH = (1.4 ± 0.2) × 10−3Tm eV = (32 ± 4) Tm kcal/mole. For the diffusion mechanism, a relation with self-diffusion is suggested, the gas most probably migrating in small vacancy clusters.

Vacuum Furnace for Metal Single Crystals

1951 ◽  
Vol 22 (3) ◽  
pp. 211-212 ◽  
Author(s):  
D. Lazarus ◽  
D. R. Chipman
Keyword(s):  
Single Crystals ◽  
Vacuum Furnace ◽  
Metal Single Crystals

scholarly journals Strength of Metal Single Crystals

Nature ◽  
1934 ◽  
Vol 133 (3372) ◽  
pp. 912-912 ◽  
Author(s):  
R. ROSCOE
Keyword(s):  
Single Crystals ◽  
Metal Single Crystals
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