Search results for "NICKEL"

Label-free histamine detection with nanofluidic diodes through metal ion displacement mechanism

2017

[EN] We design and characterize a nanofluidic device for the label-free specific detection of histamine neurotransmitter based on a metal ion displacement mechanism. The sensor consists of an asymmetric polymer nanopore fabricated via ion track-etching technique. The nanopore sensor surface having metal-nitrilotriacetic (NTA-Ni2+) chelates is obtained by covalent coupling of native carboxylic acid groups with N-alpha,N-alpha-bis(carboxymethyl)-L-lysine (BCML), followed by exposure to Ni2+ ion solution. The BCML immobilization and subsequent Ni2+ ion complexation with NTA moieties change the surface charge concentration, which has a significant impact on the current-voltage (I-V) curve after…

A simple expression for electronic stopping force of heavy ions in solids

2012

Abstract A simple expression for the electronic stopping force of heavy ions in solids is proposed based on an adaption of the Bohr’s classical stopping theory. A three-parameter model is constructed by using experimental data for helium, oxygen, argon, krypton and xenon ions in carbon, aluminum, nickel and gold targets at energies from 600 eV/u to 985 MeV/u. Total average agreements between the model and used experimental data are (−4.5 ± 47)% and (−1.6 ± 7.4)% at energies below and above the Bragg peak, respectively. The good overall agreement makes this model a good candidate for future development in stopping force prediction tools.

Metal ion beams from an ECR ion source using volatile compounds

1994

Abstract A new MIVOC method (Metal Ions from Volatile Compounds) at an ECR ion source gives a means to produce highly charged metal ion beams at room temperature conditions. Chemical compounds containing metallic atoms are utilized. The compound has to fulfill the two basic requirements: Vapour pressure of the compound is relatively high at room temperature. Evaporation and diffusion of the compound into the source take place without dissociation of the molecule. Up to present metal ion beams from iron and nickel compounds have been produced. The maximum currents of 56Fe9+ and 58Ni10+ from natural elements were 23.9 μA and 18.7 μA, respectively. First measurements have demonstrated the abil…

Multilayered samples reconstructed by measuring Kα/Kβ or Lα/Lβ X-ray intensity ratios by EDXRF

2013

Abstract In this paper a general method based on energy-dispersive X-ray fluorescence (EDXRF) analysis has been tested to assess its possible use as a tool to reconstruct the structure and determine the thickness of two and/or multi-layered materials. The method utilizes the X-ray intensity ratios of Kα/Kβ or Lα/Lβ peaks (or the ratio of these peaks) for selected elements present in multi-layered objects of various materials (Au alloys, gilded Cu, gilded Ag, gilded Pb, Ag–Au Tumbaga, stone surfaces with protective treatments, Zn or Nickel plating on metals). Results show that, in the case of multi-layered samples, a correct calculation of the peak ratio (Kα /Kβ and/or Lα/Lβ) of relevant ele…

Proton beam written hydrogen silsesquioxane (HSQ) nanostructures for Nickel electroplating

2009

Abstract Hydrogen silsesquioxane (HSQ) behaves as a negative resist under MeV proton beam exposure. HSQ is a high-resolution resist suitable for production of tall ( 1.5 μ m ) high-aspect-ratio nanostructures with dimensions down to 22 nm. High-aspect-ratio HSQ structures are required in many applications, e.g. nanofluidics, biomedical research, etc. Since P-beam writing is a direct and hence slow process, it is beneficiary to fabricate a reverse image of the patterns in a metallic stamp, e.g. by Ni electroplating. The Ni stamp can then be used to produce multiple copies of the same pattern. In this study we investigate the possibility to produce Ni stamps from p-beam written HSQ samples. H…

New approach to energy loss measurements

2002

Abstract A new approach to energy loss measurements is proposed. In the same experiment electronic stopping force (power) in gold, nickel, carbon, polycarbonate and Havar for 40 Ar, 28 Si, 16 O, 4 He and 1 H ions in the energy range 0.12–11 MeV/u has been measured. In this paper we give the full results for gold, nickel, and carbon and for 40 Ar, 16 O, 4 He and 1 H ions. Good agreement of the measured stopping force values for light ions with literature data is interpreted as the positive test of the experimental technique. The same technique used with heavy ions yields agreement with the published data only for energies above 1 MeV/u. At lower energies we observe progressively increasing d…

Energy losses of 252Cf fission fragments in thin foils

2006

Abstract The stopping power of fission fragments from 252Cf(sf) has been measured in thin foils of C, Ni, Au, Al2O3 and Mylar as a function of fragment mass and energy. The chosen stopping materials are frequently used as the backing of sources and targets or entrance windows of gas detectors. The experimental setup allowed registration of velocities of two fission fragments and energy of one of them. In this way fragment masses could be unambiguously determined and the pulse-height defect of the silicon detector verified. The measured stopping power data for fission fragments cover masses between A = 101 and A = 148. The results are compared with semi-empirical predictions of SRIM 2003 cod…

Determination of electronic stopping powers of 0.05–1MeV/u 131Xe ions in C-, Ni- and Au-absorbers with calorimetric low temperature detectors

2017

Abstract A new experimental system for precise determination of electronic stopping powers of heavy ions has been set up at the accelerator laboratory of the University of Jyvaskyla. The new setup, combining an established B-ToF system and an array of calorimetric low temperature detectors (CLTDs), has been used for the determination of electronic stopping powers of 0.05–1 MeV/u 131Xe ions in carbon, nickel and gold. Thereby advantage of the improved linearity and energy resolution of CLTDs as compared to the previously used ionization detector was taken to reduce energy calibration errors and to increase sensitivity for the energy loss determination, in particular at very low energies. The…

Studying of Nickel Alloys with 1 at.% of Ge, Zn, In, Zr and Pb by Positron Annihilation Methods

2001

Beta decay of neutron-rich cobalt and nickel isotopes

1998

We report on the first β-γ spectroscopy measurements of the neutron-rich 68–70Co and 70–74Ni nuclei, produced in proton-induced fission of 238U and ionized in a laser ion guide coupled to an on-line mass separator. Several γ lines from the decay of these nuclei have been identified, half-lives determined and production cross sections deduced. The derived level schemes for the copper and nickel isotopes show that the occupation of the ν(1g9/2) state has a strong influence on the structure of these neutron-rich nuclei. This may have a clear impact on the predicted structure and decay properties of doubly-magic 78Ni.