Cluster dynamics models of irradiation damage accumulation in ferritic iron. II. Effects of reaction dimensionality

2015 ◽  
Vol 117 (15) ◽  
pp. 154306 ◽  
Author(s):  
Aaron A. Kohnert ◽  
Brian D. Wirth
Keyword(s):  
Damage Accumulation ◽  
Irradiation Damage ◽  
Dynamics Models

Defect based spin mediation in δ-phase plutonium

2003 ◽  
Vol 802 ◽  
Author(s):  
Michael J. Fluss ◽  
Brian D. Wirth ◽  
Mark Wall ◽  
Thomas E. Felter ◽  
Maria J. Caturla ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Damage Accumulation ◽  
Ion Irradiation ◽  
Isochronal Annealing ◽  
Irradiation Damage ◽  
Structure Property ◽  
Δ Phase ◽  
Temperature Damage

ABSTRACTWe earlier reported the measured decrease of electrical resistivity during isochronal-annealing of ion irradiation damage that was accumulated at low-temperature (10 or 20K), and the temperature dependence of the resistance of defect-populations produced by low-temperature damage-accumulation and annealing in a stabilized δ-phase plutonium alloy, Pu(3.3 at%Ga)[1]. We noted that the temperature dependence of the resistance of defects resulting from low-temperature damage accumulation and subsequent annealing exhibits a -ln(T) temperature dependence suggestive of a Kondo impurity. A discussion of a possible “structure-property” effect, as it might relate to the nature of the δ-phase of Pu, is presented.

scholarly journals The closure temperature(s) of zircon Raman dating

Geochronology ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 259-272
Author(s):  
Birk Härtel ◽  
Raymond Jonckheere ◽  
Bastian Wauschkuhn ◽  
Lothar Ratschbacher
Keyword(s):  
Damage Accumulation ◽  
Isothermal Annealing ◽  
External Rotation ◽  
Raman Band ◽  
Closure Temperature ◽  
Irradiation Damage ◽  
Distributed Activation Energy Model ◽  
Geological Evidence ◽  
Annealing Step ◽  
Annealing Experiments

Abstract. Zircon Raman dating based on irradiation damage is a debated concept but not an established geo-/thermochronological method. One issue is the temperature range of radiation-damage annealing over geological timescales. We conducted isochronal and isothermal annealing experiments on radiation-damaged zircons between 500 and 1000 ∘C for durations between 10 min and 5 d to describe the annealing kinetics. We measured the widths (Γ) and positions (ω) of the ν1(SiO4), ν2(SiO4), and ν3(SiO4) internal Raman bands, and the external rotation Raman band at ∼974, 438, 1008, and 356 cm−1 after each annealing step. We fitted a Johnson–Mehl–Avrami–Kolmogorov and a distributed activation energy model to the fractional annealing data, calculated from the widths of the ν2(SiO4), ν3(SiO4), and external rotation bands. From the kinetic models, we determined closure temperatures Tc for damage accumulation for each Raman band. Tc ranges from 330 to 370 ∘C for the internal ν2(SiO4) and ν3(SiO4) bands; the external rotation band is more sensitive to thermal annealing (Tc∼260 to 310 ∘C). Our estimates are in general agreement with previous ones, but more geological evidence is needed to validate the results. The Tc difference for the different Raman bands offers the prospect of a multi-closure-temperature zircon Raman thermochronometer.

Damage Accumulation in MgAl2O4 Crystals by Xe Ion Irradiations

1993 ◽  
Vol 316 ◽  
Author(s):  
N. Yu ◽  
M. Nastasi ◽  
M.G. Hollander ◽  
C.R. Evans ◽  
C.J. Maggiore ◽  
...  
Keyword(s):  
Temperature Effect ◽  
Damage Accumulation ◽  
Rutherford Backscattering Spectrometry ◽  
Surface Region ◽  
Irradiation Damage ◽  
Spinel Layer ◽  
Near Surface ◽  
Ion Channeling ◽  
Significant Temperature

ABSTRACTWe have studied the damage kinetics in single crystal MgAl2O4 (spinel) with (100) orientation under 370 keV Xe ion irradiations at temperatures of -100 and 400 C. In-situ Rutherford Backscattering Spectrometry (RBS) and ion channeling have been used to monitor the damage accumulation in spinel following sequential Xe ion irradiations. A significant temperature effect on the irradiation damage has been found. Channeling data show that at -100 C, the irradiated spinel layer reaches the same level as in a random spectrum at a dose of 8×1015 Xe/cm2 (20 DPA for peak damage), while at 400 C, the near surface region (50 nm) remains single-crystalline up to 2×1016 Xe/cm2.

Development of a conical anode Fe-gun for low voltage SEM

1988 ◽  
Vol 46 ◽  
pp. 978-979
Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Low Voltage ◽  
Irradiation Damage ◽  
Cold Cathode ◽  
Virtual Source ◽  
Source Position ◽  
Electrostatic Lens ◽  
Electrostatic Lenses ◽  
Wide Range

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.

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