Positive-Tone Polymer Images by Surface Modification in Ion Beam Exposures

1985 ◽  
Vol 45 ◽  
Author(s):  
Hiroyuki Hiraoka

ABSTRACTUnder exposures of high energy radiation in vacuum, decarboxylation takes place efficiently on polymer surfaces having carboxylic acid groups. Low energy electron and ion beams are particularly efficient in these chemical reactions on the surfaces because their energy deposition is limited to very shallow depths. The surface areas exposed to the radiation have properties similar to hydrocarbons after decarboxylation, resulting in non-reactions in gas phase silylation, while unexposed areas undergo silylation readily due to the presence of reactive acid groups. The non-silylated areas etch faster in oxygen reactive ion etchings, giving rise to positive tone polymer images. Polymers like poly(methacrylic acid), poly(acrylic acid), and their copolymers have been used. Other polymers like poly(styrene), poly(chloromethylstyrene), and Novolac resins can also be used, because these polymers readily undergo photo-oxidation under uv-irradiation in air, generating carboxylic acid groups on their surfaces.

2006 ◽  
Vol 24 (4) ◽  
pp. 541-551 ◽  
Author(s):  
F. BECKER ◽  
A. HUG ◽  
P. FORCK ◽  
M. KULISH ◽  
P. NI ◽  
...  

An intense and focused heavy ion beam is a suitable tool to generate high energy density in matter. To compare results with simulations it is essential to know beam parameters as intensity, longitudinal, and transversal profile at the focal plane. Since the beam's energy deposition will melt and evaporate even tungsten, non-intercepting diagnostics are required. Therefore a capacitive pickup with high resolution in both time and space was designed, built and tested at the high temperature experimental area at GSI. Additionally a beam induced fluorescence monitor was investigated for the synchrotron's (SIS-18) energy-regime (60–750 AMeV) and successfully tested in a beam-transfer-line.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2770
Author(s):  
Jung Woo Kim ◽  
Seung Hwa Yoo ◽  
Young Bae Kong ◽  
Sung Oh Cho ◽  
Eun Je Lee

Two commodity polymers, polystyrene (PS) and high-density polyethylene (HDPE), were irradiated by high-energy He ion beams at low fluence to examine the wettability changes at different fluences. The water contact angles of the PS and HDPE surfaces were reduced from 78.3° to 46.7° and 81.5° to 58.5°, respectively, upon increasing the fluence from 0 to 1 × 1013 He2+/cm2 for irradiation durations ≤4 min. Surface analyses were performed to investigate these wettability changes. Surface texture evaluations via scanning electron and atomic force microscopies indicated non-remarkable changes by irradiation. However, the chemical structures of the irradiated polymer surfaces were notable. The high-energy He ions induced nuclear transmutation of C to N, leading to C–N bond formation in the polymer chains. Further, C–O and C=O bonds were formed during irradiation in air because of polymer oxidation. Finally, amide and ester groups were generated by irradiation. These polar groups improved hydrophilicity by increasing surface energies. Experiments with other polymers can further elucidate the correlation between polymer structure and surface wettability changes due to high-energy low-fluence He ion irradiation. This method can realize simple and effective utilization of commercial cyclotrons to tailor polymer surfaces without compromising surface texture and mechanical integrity.


2012 ◽  
Vol 30 (4) ◽  
pp. 679-706 ◽  
Author(s):  
Yongtao Zhao ◽  
Zhanghu Hu ◽  
Rui Cheng ◽  
Yuyu Wang ◽  
Haibo Peng ◽  
...  

AbstractIn this work, we review current trends in China to investigate beam plasma interaction phenomena. Recent progresses in China on low energy heavy ions and plasma interaction, ion beam-plasma interactions under the influences of magnetic fields, high energy heavy ion radiography through marginal range method, energy deposition of highly charged ions on surfaces and Raman spectroscopy of surfaces after irradiation of highly charged ions are presented.


Author(s):  
Peter A. Sandwall ◽  
Brandt P. Bastow ◽  
Henry B. Spitz ◽  
Howard R. Elson ◽  
Michael Lamba ◽  
...  

In radiotherapy, accurate deposition of energy to the targeted volume is vital to ensure effective treatment. Gel dosimeters are attractive detection systems, as tissue substitutes with potential to yield three-dimensional dose distributions. Radio-fluorogenesis is creation fluorescent chemical products in response to energy deposition from high-energy radiation. This report shares studies of a radio-fluorogenic gel dosimetry system, gelatin with coumarin-3-carboxlyic acid (C3CA), for the quantification of imparted energy. Aqueous solutions exposed to ionizing radiation result in the production of hydroxyl free radicals through water radiolysis. Interactions between hydroxyl free radicals and coumarin-3-carboxylic acid produce a fluorescent product. 7-hydroxy-coumarin-3-carboxylic acid has a blue (445 nm) emission, following UV to near UV (365–405 nm) excitation. Effects of C3CA concentration and pH buffers were investigated for this system. The response of the system was explored with respect to strength, type, and exposure rate of high-energy radiation. Results show a linear dose response relationship with a dose-rate dependency and no energy or type dependencies. This report supports the utility of gelatin-C3CA for phantom studies of radio-fluorogenic processes.


2021 ◽  
Vol 75 (7) ◽  
Author(s):  
Alexey V. Verkhovtsev ◽  
Ilia A. Solov’yov ◽  
Andrey V. Solov’yov

Abstract Computational multiscale modeling encompasses a wide range of end-products and a great number of technological applications. This paper provides an overview of the computational multiscale modeling approach based on utilization of MBN Explorer and MBN Studio software packages, the universal and powerful tools for computational modeling in different areas of challenging research arising in connection with the development of novel and emerging technologies. Three illustrative case studies of multiscale modeling are reviewed in relation to: (i) the development of novel sources of monochromatic high-energy radiation based on the crystalline undulators, (ii) controlled fabrication of nanostructures using the focused electron-beam induced deposition, and (iii) ion-beam cancer therapy. These examples illustrate the key algorithms and unique methodologies implemented in the software. Graphic abstract draftps


2012 ◽  
Vol 30 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Andreas Ulrich

AbstractExperiments to study the light emission from plasma produced by particle beams are presented. Fundamental aspects in comparison with discharge plasma formation are discussed. It is shown that the formation of excimer molecules is an important process. This paper summarizes various studies of particle beam induced light emission and presents the first results of a direct comparison of light emission induced by electron- and ion beam excitation. Both high energy heavy ion beam and low energy electron beam experiments are described and an overview over applications in the form of light sources, lasers, and ionization devices is given.


2006 ◽  
Vol 24 (2) ◽  
pp. 261-267 ◽  
Author(s):  
TOHRU KAWAMURA ◽  
KAZUHIKO HORIOKA ◽  
FUMIHIRO KOIKE

In this paper, potential of diagnostics with the use ofKα radiation for an energy deposition process from an intense ion-beam to background plasma is considered quantitatively.Kα radiation is a good candidate for the purpose. The wavelength ofKα radiation is varied according to the charge state of an emitter atom, and the diagnostics spatially resolved with radiations from various kinds of charge states can give us a profile of plasma temperature in a target material. For the calculation ofKα yield, an atomic population kinetics code is developed, and the result shows thatKα radiation has potential to get information of a plasma profile heated by an intense ion-beam.


Author(s):  
A.J. Tousimis

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.


Author(s):  
A. K. Rai ◽  
R. S. Bhattacharya ◽  
M. H. Rashid

Ion beam mixing has recently been found to be an effective method of producing amorphous alloys in the binary metal systems where the two original constituent metals are of different crystal structure. The mechanism of ion beam mixing are not well understood yet. Several mechanisms have been proposed to account for the observed mixing phenomena. The first mechanism is enhanced diffusion due to defects created by the incoming ions. Second is the cascade mixing mechanism for which the kinematicel collisional models exist in the literature. Third mechanism is thermal spikes. In the present work we have studied the mixing efficiency and ion beam induced amorphisation of Ni-Ti system under high energy ion bombardment and the results are compared with collisional models. We have employed plan and x-sectional veiw TEM and RBS techniques in the present work.


Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.


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