Search results for "Fabric"

Fabrication of a gap structure for near-field heat transfer

2016

Tutkimuksessa kehitettiin kahden vaiheen valmistusprosessi rakorakenteen valmistamiseen, jossa on metallista valmistetut johdot. Tämä rakorakenne on tarkoitettu lähikentän lämmönsiirtymisen mittaamiseen. Valmistus tehtiin pääasiassa 3D-litografialla käyttämällä Nanoscribe Photonic Professional -järjestelmää. Valmistukseen sisältyi myös ALD (Atomic Layer Deposition), metallipäällystys höyrystämällä, lift-off ja ionisuihkujyrsintä. Valmistettu rakenne koostuu kahdesta suorakulmaisesta särmiöstä lähellä toisiaan, jotka muodostavat ripustetun yhdensuuntaisten tasojen geometrian. Särmiöiden päälle tehdyt metalloinnit koostuivat ohuesta kultalangasta, joka voi toimia resistiivisenä lämpömittarina…

El negocio mundial de las minas y de la tortura

1997

Investigation of heavy ion tracks in LiF crystals by dislocation mobility method

2008

Abstract The track damage created in LiF by swift heavy ions was studied using methods of dislocation mobility and track etching. The crystals were irradiated with Bi and Pb ions of a specific energy of 11 MeV/u at fluences between 10 7 and 10 10  cm −2 . The measurements on cross-sections cleaved parallel to the irradiated surface showed continuity of the track etching for the depth up to 70% of the ion range. In deeper layers, numerous etch pits had a flat-bottomed shape indicating the discontinuities of the track structure. At this stage, a decrease of the ion-induced effect in dislocation mobility was observed. The observed reduction of the efficiency of ion tracks as obstacles for disl…

A pulsed high-voltage decelerator system to deliver low-energy antiprotons

2021

International audience; The GBAR (Gravitational Behavior of Antihydrogen at Rest) experiment at CERN requires efficient deceleration of 100 keV antiprotons provided by the new ELENA synchrotron ring to synthesize antihydrogen. This is accomplished using electrostatic deceleration optics and a drift tube that is designed to switch from -99 kV to ground when the antiproton bunch is inside – essentially a charged particle “elevator” – producing a 1 keV pulse. We describe the simulation, design, construction and successful testing of the decelerator device at -92 kV on-line with antiprotons from ELENA.

Utilisation of a sputtering device for targetry and diffusion studies

2004

A novel device for versatile sputtering applications is described. The apparatus design is realised for fulfilling the demands of both nuclear physics experiment target production and serial sectioning in solid-state diffusion studies with radiotracers. Results of several tests are reported, characterising the devise performance in these two differing applications.

Fabrication of a negative PMMA master mold for soft-lithography by MeV ion beam lithography

2012

Abstract In this study, poly(methyl methacrylate) (PMMA) was investigated as a negative resist by irradiation with a high-fluence 2 MeV proton beam. The beam from a 1.7 MV Tandetron accelerator at the Plasma and Beam Physics Research Facility (PBP) of Chiang Mai University is shaped by a pair of computer-controlled L-shaped apertures which are used to expose rectangular pattern elements with 1–1000 μm side length. Repeated exposure of rectangular pattern elements allows a complex pattern to be built up. After subsequent development, the negative PMMA microstructure was used as a master mold for casting poly(dimethylsiloxane) (PDMS) following a standard soft-lithography process. The PDMS chi…

High magnification SEM observations for two types of granularity in a high burnup PWR fuel rim

1998

Abstract Rim microstructure of an UO2 pellet irradiated up to 61 GWd/tU, observed with high magnification scanning electron microscopy, presented two types of subgrains: polyhedral and round subgrains. Round subgrains were also observed on the surface of fabrication pores along the pellet radius. These round-shaped subgrains seem to be associated to free surface rearrangement. This new type of round subgrains was proved to be independent of the rim effect. Observations of the fuel structure in the vicinity of rim area evidenced two types of defects specific to rim effect: planar defects and small intergranular pores. Hypothesis is made that the accumulation of planar defects could generate …

Thin film growth into the ion track structures in polyimide by atomic layer deposition

2017

Abstract High-aspect ratio porous structures with controllable pore diameters and without a stiff substrate can be fabricated using the ion track technique. Atomic layer deposition is an ideal technique for depositing thin films and functional surfaces on complicated 3D structures due to the high conformality of the films. In this work, we studied Al2O3 and TiO2 films grown by ALD on pristine polyimide (Kapton HN) membranes as well as polyimide membranes etched in sodium hypochlorite (NaOCl) and boric acid (BO3) solution by means of RBS, PIXE, SEM-EDX and helium ion microcopy (HIM). The focus was on the first ALD growth cycles. The areal density of Al2O3 film in the 400 cycle sample was det…

Development of elastomeric lab-on-a-chip devices through Proton Beam Writing (PBW) based fabrication strategies

2009

Abstract In recent years, one of the most exciting developments in fluidic device applications is the rapid evolution of miniaturized micro- and nanofluidic systems, the so called “lab-on-a-chip” devices. These devices integrate laboratory functions into a single chip, and are capable of various biochemical analysis and synthesis, such as sample injection and preparation, single cell/molecule observation, bioparticle sequencing and sorting etc. The evolvement of lab-on-a-chip concept implies the use of novel fabrication techniques for the construction of versatile analytical components in a fast and reproducible manner. Endowed with unique three-dimensional fabrication abilities, Proton Bea…

Dislocation mobility study of heavy ion induced track damage in LiF crystals

2008

Track damage created in LiF crystals by swift U, Kr, Xe and Ni ions with a specific energy of 11.1 MeV/u was studied using dislocation mobility measurements, track etching, SEM, AFM and optical microscopy. The results demonstrate continuity of etching of U tracks while discontinuities of etching are observed in the case of Xe ions. The relationship between the track structure and dislocation mobility in irradiated crystals is discussed. The dislocation mobility technique can serve as a highly sensitive method for track core damage studies.