Effective removal of field-emitting sites from metallic surfaces by dry ice cleaning

Dangwal, A.; Müller, Günter; Reschke, D.; Floettmann, K.; Singer, X.

doi:10.1063/1.2772505

Cited by 12 publications

(9 citation statements)

References 16 publications

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“…The removal of particulates, light organics, and photoresist residues less than 100 nm in size from surfaces of photomask substrates, etched wafers, and semiconductors was investigated by Brandt [15], Dangwal et al [26], Kosic and Palser [27], and Yang et al [10]. Loosely bound contaminants and particles were successfully removed by CO 2 snow, and the gas spray was sufficient to carry off the loosened particles.…”

Section: Dry-ice Cleaning Applicationsmentioning

confidence: 99%

Physical Methods for Cleaning and Disinfection of Surfaces

et al. 2011

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Cleaning and disinfection are important operations in food processing because of the significant contributions to product hygiene and food safety. The transfer of residues from surfaces into a product and the contamination with adhering microorganisms must therefore be avoided with sufficient certainty. Traditional methods for the removal of adherents and inactivation of microorganisms are based on thermal, mechanical, or chemical principles and are known to be time-and energy-consuming. This has resulted in a search for alternative methods that show prospective potential for their use in food-processing plants. This review gives an overview on such methods, which are based on physical principles. In dry-ice cleaning, for example, carbon dioxide snow pellets are blasted onto a surface to remove adherents through a combined action of thermal and mechanical effects, followed by dissolution of these adherents. Ice-pigging is a procedure where an ice/ water mixture is forced through pipes, heat exchangers, or other equipment to carry off adhered substances. Another method for physical cleaning, mainly described in context with membrane filtration, is to use vibration in the ultrasonic frequency domain to reduce fouling and to stabilize permeate flux. Radiation from various sources (UV lamps, radionuclides, X-ray tubes) differs in its applicability and disinfection efficiency because of differences in energy and penetration depth. Cold plasma treatment is another promising technology that is currently under investigation for cleaning and disinfection of surfaces of inorganic and organic materials.

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Section: Dry-ice Cleaning Applicationsmentioning

confidence: 99%

Physical Methods for Cleaning and Disinfection of Surfaces

et al. 2011

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“…The composition of organic contaminants before and after cleaning was analyzed using X-ray photoelectron spectroscopy. Furthermore, the cleaning performance of dry ice blasting was investigated using infrared spectroscopy (Hills et al 1995), and field emission scanning microscopy (Dangwal et al 2007). Dry ice cleaning methods have excellent performance for many applications such as the cleaning of products or equipment in electrical, automobile, and food industries, etc.…”

Section: Introductionmentioning

confidence: 99%

Effect of Particle Impact on Surface Cleaning Using Dry Ice Jet

Liu

Maruyama

Matsusaka

2011

Aerosol Science and Technology

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The removal of particulate contaminants adhering to a surface has been investigated using a dry ice blasting system. Monosized spherical latex particles of micron and submicron sizes were used as particulate contaminants, while the dry ice jet was produced by the thermal expansion of liquid carbon dioxide (CO 2). Removal of the contaminants was observed in situ using a high-speed microscope camera and quantified through digital image analysis. The experimental results showed that dry-ice blasting performs well for surface cleaning, which is attributed to the collision of the dry ice particles with the contaminants. For submicron-sized contaminants, a lower temperature jet was required in order to produce a larger number of dry ice particles to enhance the removal efficiency. The removal efficiency increased with an increase of the jet pressure on the surface. In addition, a theoretical analysis of the moments of forces caused by particle impact and aerodynamic drag showed that particle impact is primarily responsible for removal. Furthermore, the effect of the dry ice cleaning was visually observed by applying it to the removal of a film resin covering a surface.

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“…Field emission scanning microscopy (FESM) and correlated SEM measurements with energy-dispersive X-ray spectroscopy (EDX) of Nb and Cu samples relevant for recent accelerating structures confirmed particulates and surface defects as main origin of EFE with field enhancement factors β ¼ 10 À 120 and typical emission areas S ¼ 10 À 4 À 10 4 μm 2 [8][9][10]. Although the emitter number density N can be significantly reduced by high pressure rinsing [11,12] and dry ice cleaning [13,14], N increases strongly even on cleaned surfaces with the applied macroscopic electric surface field E s . It is remarkable, that field emitters on Nb usually become activated at a certain field level E s ¼ E act , which is usually much higher than the final macroscopic onset field E on , both defined for a current of 1 nA.…”

Section: Introductionmentioning

confidence: 99%