Computer Simulation of Channeling Effects in Ion Implantation

1992 ◽  
Vol 279 ◽  
Author(s):  
Matthias Posselt
Keyword(s):  
Nuclear Energy ◽  
Energy Deposition ◽  
Crystalline Silicon ◽  
Electronic Energy ◽  
Maximum Penetration Depth ◽  
Two Factors ◽  
Radiation Induced ◽  
Maximum Penetration ◽  
Amorphous Surface ◽  
Higher Doses

ABSTRACTOur binary collision code Crystal-TRIM is applied to simulate 1 MeV P+ implantation into single-crystalline silicon at ion incidence into the [100] axial channel direction and doses between 2 × 1013 cm−2 and 6.7 × 1014 cm−2. The maximum penetration depth of the ions is determined by the electronic stopping of the well-channeled particles. The shape of the range distributions depends on (i) the thin amorphous surface layer on silicon, (ii) the radiation-induced production of vacancies and interstitials, and (iii) the static atomic disorder due to electronic energy deposition. The comparison of experimental data with results of computer simulations shows that at low doses at least the influence of the first two factors has to be considered. At higher doses the radiation damage due to nuclear energy deposition dominates the other effects.

scholarly journals Ion tracks in silicon formed by much lower energy deposition than the track formation threshold

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Amekura ◽  
M. Toulemonde ◽  
K. Narumi ◽  
R. Li ◽  
A. Chiba ◽  
...  
Keyword(s):  
Nuclear Energy ◽  
Energy Deposition ◽  
Ion Irradiation ◽  
High Energy ◽  
Electronic Energy ◽  
Synergy Effect ◽  
Ion Tracks ◽  
Track Formation ◽  
Low Energies ◽  
High Energy Ions

AbstractDamaged regions of cylindrical shapes called ion tracks, typically in nano-meters wide and tens micro-meters long, are formed along the ion trajectories in many insulators, when high energy ions in the electronic stopping regime are injected. In most cases, the ion tracks were assumed as consequences of dense electronic energy deposition from the high energy ions, except some cases where the synergy effect with the nuclear energy deposition plays an important role. In crystalline Si (c-Si), no tracks have been observed with any monomer ions up to GeV. Tracks are formed in c-Si under 40 MeV fullerene (C60) cluster ion irradiation, which provides much higher energy deposition than monomer ions. The track diameter decreases with decreasing the ion energy until they disappear at an extrapolated value of ~ 17 MeV. However, here we report the track formation of 10 nm in diameter under C60 ion irradiation of 6 MeV, i.e., much lower than the extrapolated threshold. The diameters of 10 nm were comparable to those under 40 MeV C60 irradiation. Furthermore, the tracks formed by 6 MeV C60 irradiation consisted of damaged crystalline, while those formed by 40 MeV C60 irradiation were amorphous. The track formation was observed down to 1 MeV and probably lower with decreasing the track diameters. The track lengths were much shorter than those expected from the drop of Se below the threshold. These track formations at such low energies cannot be explained by the conventional purely electronic energy deposition mechanism, indicating another origin, e.g., the synergy effect between the electronic and nuclear energy depositions, or dual transitions of transient melting and boiling.

scholarly journals Ion-Irradiation-Induced Densification of Zirconia Sol -Gel Thin Films

1993 ◽  
Vol 316 ◽  
Author(s):  
Timothy E. Levine ◽  
Emmanuel P. Giannelis ◽  
Padma Kodali ◽  
Joseph Tesmer ◽  
Michael Nastasi ◽  
...  
Keyword(s):  
Nuclear Energy ◽  
Energy Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Irradiation ◽  
Sol Gel ◽  
Electronic Energy ◽  
Target Atom ◽  
Recoil Energy ◽  
Ion Energies ◽  
Sol Gel Films

ABSTRACTWe have investigated the densification behavior of sol-gel zirconia films resulting from ion irradiation. Three sets of films were implanted with neon, krypton, or xenon. The ion energies were chosen to yield approximately constant energy loss through the film and the doses were chosen to yield similar nuclear energy deposition. Ion irradiation of the sol-gel films resulted in carbon and hydrogen loss as indicated by Rutherford backscattering spectrometry and forward recoil energy spectroscopy. Although the densification was hypothesized to result from target atom displacement, the observed densification exhibits a stronger dependence on electronic energy deposition.

scholarly journals Investigating the Influence of Ion Species on the Irradiation-Induced Mechanical Properties of Borosilicate Glass

2021 ◽  
Vol 11 (8) ◽  
pp. 3473
Author(s):  
Yedong Guan ◽  
Peng Lv ◽  
Zuojiang Wang ◽  
Yuzhe Jiang ◽  
Zhao Sun ◽  
...  
Keyword(s):  
Borosilicate Glass ◽  
Nuclear Energy ◽  
Energy Deposition ◽  
Ion Irradiation ◽  
Electronic Energy ◽  
Irradiation Effects ◽  
Maximum Decrease ◽  
The Mean ◽  
Ion Species

Investigating the irradiation effects on borosilicate glass is of great significance for understanding the long-term evolutions of this substance in radioactive environments. In the present study, the hardness and modulus of conventional and ion-irradiated borosilicate glass were investigated through nanoindentation measurements. The obtained results show that the maximum decrease of the mean hardness after He and Ar ion irradiation was 8.4% and 17.0%, respectively, when the fluence reached 1.1 × 1015. It was found that the hardness reduction had a significant ionic correlation. Meanwhile, it was observed that the mean modulus increased by less than 5.0%, while there was no meaningful ionic correlation. The variation in hardness and modulus were primarily the consequence of nuclear energy deposition. The hardness recovery was observed under Ar-irradiated and He-irradiated Ar pre-damaged samples. It was concluded that the hardness recovery mainly originates from electronic energy deposition induced by ion irradiation.

scholarly journals Reduced High-Dose Radiation-Induced Residual Genotoxic Damage by Induction of Radioadaptive Response and Prophylactic Mild Dietary Restriction in Mice

Dose-Response ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 155932582098216
Author(s):  
Bing Wang ◽  
Kaoru Tanaka ◽  
Takanori Katsube ◽  
Kouichi Maruyama ◽  
Yasuharu Ninomiya ◽  
...  
Keyword(s):  
Dietary Restriction ◽  
High Dose ◽  
Cancer Treatments ◽  
Hematopoietic Stem ◽  
Beneficial Effects ◽  
Radiation Induced ◽  
Potential Strategy ◽  
Higher Doses

Radioadaptive response (RAR) describes a phenomenon in a variety of in vitro and in vivo systems that a low-dose of priming ionizing radiation (IR) reduces detrimental effects of a subsequent challenge IR at higher doses. Among in vivo investigations, studies using the mouse RAR model (Yonezawa Effect) showed that RAR could significantly extenuate high-dose IR-induced detrimental effects such as decrease of hematopoietic stem cells and progenitor cells, acute radiation hematopoietic syndrome, genotoxicity and genomic instability. Meanwhile, it has been demonstrated that diet intervention has a great impact on health, and dietary restriction shows beneficial effects on numerous diseases in animal models. In this work, by using the mouse RAR model and mild dietary restriction (MDR), we confirmed that combination of RAR and MDR could more efficiently reduce radiogenotoxic damage without significant change of the RAR phenotype. These findings suggested that MDR may share some common pathways with RAR to activate mechanisms consequently resulting in suppression of genotoxicity. As MDR could also increase resistance to chemotherapy and radiotherapy in normal cells, we propose that combination of MDR, RAR, and other cancer treatments (i.e., chemotherapy and radiotherapy) represent a potential strategy to increase the treatment efficacy and prevent IR risk in humans.

scholarly journals Response of Shallots of Batu Ijo Variety on Doses of N And K Fertilizers

Akta Agrosia ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 19-24
Author(s):  
Widodo Widodo ◽  
Marlin Marlin ◽  
Nancy B. Sitio
Keyword(s):  
Plant Growth ◽  
N Fertilizer ◽  
Tuber Weight ◽  
Plant Weight ◽  
Randomized Design ◽  
K Fertilizer ◽  
Two Factors ◽  
Number Of Leaves ◽  
Completely Randomized Design ◽  
Higher Doses

Shallots (Allium cepa var. Aggregatum L) have many varieties that can be grown in the highlands and lowlands and one of them is the Batu Ijo variety. Nutrients N and K play an important role for plant needs. This research was conducted from March to June 2019 in Medan Baru, Bengkulu City. This study used a completely randomized design with two factors. The first factor was the dose of N fertilizer and the second factor was the application of K fertilizer. The application of N fertilizer had a significant effect on the number of shallots at week 2. The Urea dose given decreases the number of spring onions. For the best treatment at plant height is the treatment of Urea 300 kg/ha and KCl 50 kg/ha. Plant growth from week 2 to 5 increased significantly. The application of K fertilizer has an effect on the number of shallots at week 2 and the number of tubers. The higher the plant age, the more the number of leaves produced, but at higher doses, the number of leaves and the number of tubers decreased. The best treatment for the number of leaves produced was Urea 300 kg/ha and without giving KCl. For the best treatment of fresh plant weight, namely Urea 300 kg/ha and KCl 150 kg/ha, the best treatment fresh tuber weight was Urea 300 kg/ha and KCl 150 kg/ha, for tuber diameter the best treatment was 200 kg/ha of urea and KCl 100 kg/ha and for the number of tubers of Urea 0 kg/ha and KCl 150 kg/ha.Keywords: shallots, N fertilizer, K fertilizer

scholarly journals Dynamic statistical assessment of the competitiveness of an energy generating company (as exemplified by Rosenergoatom Concern JSC)

2021 ◽  
Vol 7 (4) ◽  
pp. 327-332
Author(s):  
Tatiana A. Burtseva ◽  
Sergey S. Khvorostyannikov ◽  
Anastasia A. Kuznetsova
Keyword(s):  
Energy Efficiency ◽  
National Economy ◽  
Nuclear Energy ◽  
Nuclear Industry ◽  
Total Energy Consumption ◽  
Russian Economy ◽  
The World ◽  
Two Factors ◽  
The Government ◽  
High Level

The depletion of traditional organic energy sources and aggravated environmental problems are the reasons why the level of energy efficiency is an important factor in the competitiveness of the national economy. Russia ranks third in the world in terms of total energy consumption and its economy is distinguished by a high level of energy intensity (amount of energy per unit of GDP). In 2019, this figure was 9.62 tons of oil equivalent (toe) per 1 million rubles, which is 40% higher than the world average. The low energy efficiency of the Russian economy is a widely recognized problem. A special decree of the Government of Russia in 2018 sets the task of increasing the level of energy efficiency of the Russian economy by 23% by 2030. One of the ways to solve this problem is the development of nuclear energy, and increasing the competitiveness of nuclear energy is one of the key issues for the national economy. In this connection, solving the problem of assessing the competitiveness of the nuclear industry and its leading companies occupies a key place among the practical scientific problems, the solution of which is facilitated by the results presented by the authors in this article. Rosenergoatom Concern JSC is the leading energy generating company in the Russian nuclear industry. The results of the study of the competitiveness of Rosenergoatom Concern JSC were obtained on the basis of the authors’ methodology for assessing the competitiveness of an energy generating company. The novelty of the presented methodology lies in the developed normative and evaluative model and the coefficients of competitiveness of an energy generating company. The advantages of the authors’ model are that it allows (1) obtaining integral assessments of the competitiveness of a power generating company at short time intervals for a large number of indicators and (2) quantitatively measuring the effects of different factors on the competitiveness of a power generating company, provided that the grouping of indicators of competitiveness of a power generating company is justified by influencing factors. The two factors considered by the authors were: the general market factor and the industry factor. According to the results of the study, it was found that Rosenergoatom Concern JSC demonstrates positive increase of the competitiveness indicator mainly due to the industry factor. With this regard, it was concluded that, within the framework of state policy, it is advisable to strengthen support for the Russian nuclear industry by creating additional conditions and opportunities for its energy generating companies on the domestic energy market.

Design and Tests of a Multi-pin Flexible Seedling Pick-up Gripper for Automatic Transplanting

2019 ◽  
Vol 35 (6) ◽  
pp. 949-957 ◽  
Author(s):  
Luhua Han ◽  
Francis Kumi ◽  
Hanping Mao ◽  
Jianping Hu
Keyword(s):  
Control System ◽  
Penetration Depth ◽  
Working Pressure ◽  
Pneumatic Control ◽  
Position Detection ◽  
Maximum Penetration Depth ◽  
Timely Response ◽  
Plug Seedling ◽  
Maximum Penetration ◽  
Push Out

HighlightsA multi-pin flexible pick-up gripper with a four-jaw chuck having four pick-up pins has been developed.The gripper can effectively grasp, hold and release plug seedlings with low damages to the plants and the root soil.Based on a typical on-off control and cylinder stroke position detection, the control system for timely response was designed to automate the process of picking up and releasing seedlings.Abstract. A multi-pin flexible seedling pick-up gripper for automatic transplanting was developed and evaluated. The gripper having a four-jaw chuck mainly consists of a parallel-type air gripper with four fingers, four fork frames, four cylinder fingers, and several connecting/supporting parts. The air gripper moves to open and close the cylinder fingers, and the cylinder fingers each having a flexible pin grasp and release the seedling. When the pick-up gripper extracts seedlings from the tray cells, its four cylindrical fingers push out four pick-up pins to penetrate deep into the root soil and then close, making the pick-up pins to firmly hold the root soil for lifting. When the pick-up gripper releases seedlings, its fingers open, making the pick-up pins loosen the root soil and then pull back for discharging. An electrical and pneumatic control system was designed to coordinate the execution of each action. The pick-up gripper attached to a robotic manipulator was tested on a range of plug seedling transplanting parameters and conditions. The results showed that penetration depth, seedling species, and the interaction of working pressure and seedling species significantly influenced the successful automatic transplanting. On the whole, the seedling integrity ratio in automatic transplanting was found to be up to 93.37%. For optimum performance of the device in transplanting seedlings, the pick-up pins of the multi-pin gripper need to grasp the maximum amount of root soil at their maximum penetration depth. Keywords: Gripper, Flexible, Multi-pin, Seedlings, Transplanting.

Strahleninduzierte freie Radikale in phosphororganischen Verbindungen

1968 ◽  
Vol 23 (6) ◽  
pp. 771-777 ◽  
Author(s):  
G. Lassmann ◽  
W. Damerau ◽  
Kh. Lohs
Keyword(s):  
Yield Curve ◽  
Oxygen Effect ◽  
State Matrix ◽  
The Matrix ◽  
X Irradiation ◽  
Radiation Induced ◽  
Kinetics Of ◽  
Dose Dependent ◽  
Higher Doses ◽  
High Irradiation

Chlorine containing phosphonic acid esters (tridilorphon-type) have been investigated quantitatively by ESR after X-irradiation at room temperature. Radical yields are between 0.2 and 1.7 radicals per 100 eV. In the case of trichlorphon the radical concentration is 7.5·1018 spins per gram at 40 Mrad.Stabilisation and kinetics of radiation-induced radicals in the solid state matrix at high irradiation doses in dependence of storage time, oxygen-effect and temperature are discussed. The obtained results suggest a model for the behaviour of the matrix at high irradiation doses. According to this model the lattice of molecular crystals is modified by the accumulation of recombination products arising from the induced radicals. These lattice imperfections cause a diminution of stabilizing properties for the radicals. The decrease of the dose-yield-curve at higher doses than 40 Mrad and the dose-dependent radical kinetics during storage can be explained by this model.

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