Kai Nordlund

Application of molecular dynamics for low-energy ion implantation in crystalline silicon

Publisher: American Vacuum Society

Date: 2006

DOI: 10.1116/1.2137333

Abstract: Molecular dynamics (MD) is set to replace Monte Carlo (MC) methods utilizing the binary collision approximation (BCA) in modeling dopant distributions after ion implantation in the low energy regime. Simultaneous nonbinary interactions come into play as the ion slows down unlike BCA, MD automatically accounts for multiple collisions between ion and its neighboring atoms. In this work, the energy limit below which BCA fails is estimated from density functional theory (DFT) calculations for a wide range of dopants. Impurity profiles are generated using the MD code, MDRANGE. A database consisting of secondary ion mass spectrometry (SIMS) profiles covering a wide range of dopants (B, C, F, N, P, As, Ge, In, and Sb) over the energy regime of 0.5–10keV at critical channeling directions have been set up. The MD simulated profiles show good agreement with SIMS data, which have been obtained either with a quadrupole—or magnetic-sector—based mass spectrometer.

Fine Structure in Swift Heavy Ion Tracks in AmorphousSiO2

Publisher: American Physical Society (APS)

Date: 24-10-2008

DOI: 10.1103/PHYSREVLETT.101.175503

Dependence of short and intermediate-range order on preparation in experimental and modeled pure a-Si

Publisher: Elsevier BV

Date: 04-2016

DOI: 10.1016/J.JNONCRYSOL.2016.02.008

Overview of the JET results in support to ITER

Publisher: IOP Publishing

Date: 15-06-2017

DOI: 10.1088/1741-4326/AA5E28

CERN Yellow Reports, Vol 4 (2016): Updated Baseline for a staged Compact Linear Collider

Publisher: CERN, Geneva

Date: 2016

DOI: 10.5170/CERN-2016-004

Latent ion tracks in amorphous silicon

Publisher: American Physical Society (APS)

Date: 25-11-2013

DOI: 10.1103/PHYSREVB.88.174111

Ion-irradiation-induced amorphization of cobalt nanoparticles

Publisher: American Physical Society (APS)

Date: 06-04-2010

DOI: 10.1103/PHYSREVB.81.155414

Atomistic simulation of the measurement of mechanical properties of gold nanorods by AFM

Publisher: Springer Science and Business Media LLC

Date: 24-11-2017

DOI: 10.1038/S41598-017-16460-9

Abstract: Mechanical properties of nanoscale objects can be measured with an atomic force microscope (AFM) tip. However, the continuum models typically used to relate the force measured at a certain indentation depth to quantities such as the elastic modulus, may not be valid at such small scales, where the details of atomistic processes need to be taken into account. On the other hand, molecular dynamics (MD) simulations of nanoindentation, which can offer understanding at an atomistic level, are often performed on systems much smaller than the ones studied experimentally. Here, we present large scale MD simulations of the nanoindentation of single crystal and penta-twinned gold nanorod s les on a silicon substrate, with a spherical diamond AFM tip apex. Both the s le and tip sizes and geometries match commercially available products, potentially linking simulation and experiment. Different deformation mechanisms, involving the creation, migration and annihilation of dislocations are observed depending on the nanorod crystallographic structure and orientation. Using the Oliver-Pharr method, the Young’s moduli of the (100) terminated and (110) terminated single crystal nanorods, and the penta-twinned nanorod, have been determined to be 103 ± 2, 140 ± 4 and 108 ± 2 GPa, respectively, which is in good agreement with bending experiments performed on nanowires.

Molecular dynamics with phase-shift-based electronic stopping for calibration of ion implantation profiles in crystalline silicon

Publisher: Elsevier BV

Date: 05-2006

DOI: 10.1016/J.TSF.2005.09.153

The effect of interatomic potential in molecular dynamics simulation of low energy ion implantation

Publisher: Elsevier BV

Date: 2005

DOI: 10.1016/J.NIMB.2004.10.051

Atomic force microscope adhesion measurements and atomistic molecular dynamics simulations at different humidities

Publisher: IOP Publishing

Date: 23-01-2017

DOI: 10.1088/1361-6501/28/3/034004

Overview of JET results for optimising ITER operation

Publisher: IOP Publishing

Date: 04-2022

DOI: 10.1088/1741-4326/AC47B4

Abstract: The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W ertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and tested the technical and procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle ( α ) physics in the coming D–T c aign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed shattered pellet injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design and operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D–T benefited from the highest D–D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER.

CERN Yellow Reports: Monographs, Vol 2 (2018): The Compact Linear e+e− Collider (CLIC) : 2018 Summary Report

Publisher: CERN

Date: 1970

DOI: 10.23731/CYRM-2018-002

Nanoscale density variations induced by high energy heavy ions in amorphous silicon nitride and silicon dioxide

Publisher: IOP Publishing

Date: 19-02-2018

DOI: 10.1088/1361-6528/AAABDB

Abstract: The cylindrical nanoscale density variations resulting from the interaction of 185 MeV and 2.2 GeV Au ions with 1.0 μm thick amorphous SiN

Tracks and Voids in Amorphous Ge Induced by Swift Heavy-Ion Irradiation

Publisher: American Physical Society (APS)

Date: 14-06-2013

DOI: 10.1103/PHYSREVLETT.110.245502

SAXS investigations of the morphology of swift heavy ion tracks in α-quartz

Publisher: IOP Publishing

Date: 13-12-2012

DOI: 10.1088/0953-8984/25/4/045006

Abstract: The morphology of swift heavy ion tracks in crystalline α-quartz was investigated using small angle x-ray scattering (SAXS), molecular dynamics (MD) simulations and transmission electron microscopy. Tracks were generated by irradiation with heavy ions with energies between 27 MeV and 2.2 GeV. The analysis of the SAXS data indicates a density change of the tracks of ~2 ± 1% compared to the surrounding quartz matrix for all irradiation conditions. The track radii only show a weak dependence on the electronic energy loss at values above 17 keV nm(-1), in contrast to values previously reported from Rutherford backscattering spectrometry measurements and expectations from the inelastic thermal spike model. The MD simulations are in good agreement at low energy losses, yet predict larger radii than SAXS at high ion energies. The observed discrepancies are discussed with respect to the formation of a defective halo around an amorphous track core, the existence of high stresses and/or the possible presence of a boiling phase in quartz predicted by the inelastic thermal spike model.

Nanoindentation of gold nanorods with an atomic force microscope

Publisher: IOP Publishing

Date: 28-11-2014

DOI: 10.1088/2053-1591/1/4/045042

Review on the EFDA programme on tungsten materials technology and science

Publisher: Elsevier BV

Date: 10-2011

DOI: 10.1016/J.JNUCMAT.2011.01.075

Efficient generation of energetic ions in multi-ion plasmas by radio-frequency heating

Publisher: Springer Science and Business Media LLC

Date: 19-06-2017

DOI: 10.1038/NPHYS4167

Nanoscale density fluctuations in swift heavy ion irradiated amorphous SiO2

Publisher: AIP Publishing

Date: 15-12-2011

DOI: 10.1063/1.3671614

Abstract: We report on the observation of nanoscale density fluctuations in 2 μm thick amorphous SiO2 layers irradiated with 185 MeV Au ions. At high fluences, in excess of approximately 5 × 1012 ions/cm2, where the surface is completely covered by ion tracks, synchrotron small angle x-ray scattering measurements reveal the existence of a steady state of density fluctuations. In agreement with molecular dynamics simulations, this steady state is consistent with an ion track “annihilation” process, where high-density regions generated in the periphery of new tracks fill in low-density regions located at the center of existing tracks.

University Of Helsinki

Location: Finland

View Organisation

Discovery Projects - Grant ID: DP180100068

Start Date: 03-2018

End Date: 12-2022

Amount: $463,387.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP120101264

Start Date: 2012

End Date: 12-2014

Amount: $320,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0877721

Start Date: 06-2008

End Date: 05-2013

Amount: $980,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP190100200

Start Date: 03-2019

End Date: 03-2024

Amount: $400,000.00

Funder: Australian Research Council