We have developed a method to produce micro/nano meter sized beams of keV energy highly charged ions (HCIs) and MeV energy protons/He ions with tapered glass capillary optics for application of ...surface modifications and a biological tool called “cell surgery”, respectively. The transmission through the tapered glass capillaries with inlet diameter of 0.8
mmϕ, outlet diameter from 900
nmϕ to several tens of microns and length of about 50
mm was performed using 8/64
keV Ar
8+ beams. The transmitted beams had a density enhancement of about 10 and were guided through a capillary tilted by as large as ±100
mrad. The charge state of the beams was kept during the transmission. The combination of MeV proton/He ion beams and the capillary with a thin end window at its outlet can realize pinpoint energy deposition and three-dimensional selection of the bombarding point in an arbitrary position of a living cell or in any liquid object. We demonstrated that a real biological cell, HeLa cell with the nucleus labeled by green fluorescent protein (GFP), was irradiated with the microbeam, which was prepared by 4
MeV He
2+ entering a capillary with an end window of 7.3
μm in thickness and outlet diameter of 9.6
μmϕ. The transmitted MeV ion beams had density enhancement up to 1000 according to the capillary outlet sizes, which are applicable to various material analyses employing microbeams.
► Micro/nano meter sized ion beams are provided by tapered glass capillaries. ► Capillary’s inner radius was measured as a function of position along its axis. ► Density enhancement and guiding effect can be expected for keV ion beams. ► Combination of MeV ions and end windows has the possibility to realize cell surgery. ► Density enhancement of muon beams was also obtained by tapered insulator tubes.
The Baikal neutrino experiment Avrorin, A.; Aynutdinov, V.; Balkanov, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2011, Letnik:
626
Journal Article
Recenzirano
Odprti dostop
We review the status of the Lake Baikal Neutrino Experiment. Preparation towards a km
3-scale Gigaton Volume Detector (GVD) in Lake Baikal is currently a central activity. As an important milestone, ...a km
3-prototype string comprising of 12 optical modules and based on a completely new technology, has been installed and was put in operation together with NT200+ in April, 2009. We also present recent results from the long-term operation of NT200, including an improved limit on the diffuse astrophysical neutrino flux.
For the first time a classical model was developed to describe quantitatively the dynamics of charge distribution formation on a planar dielectric surface during its irradiation by fast electrons at ...a grazing incidence. The dynamic effects of the mutual influence of the beam and the dielectric surface charge predicted by the developed model are in a good agreement with the performed experiments. The proposed model can be used to describe time dependent processes of the electron beam–dielectric surface interaction, charging up and discharging for dielectric channels of more complex shapes.
•The first model to describe the guiding process of a 10-keV electron beam by dielectric surface was developed.•The model can describe time processes during electron–surface interaction.•The model takes into account secondary electron emission from the surface.•The function of charge up dependence on angle of incidence is proposed.•The mechanism of charge leakage is proposed for one-dimensional model.
In this work, we suggest a theoretical model that explains the interesting phenomenon of the regular oscillations of the current of ions transmitted through a dielectric capillary. The model is based ...on the assumption that upon the collision of ions with capillary wall, defects having a vacant state of electrons are generated on its surface. If the concentration of these defects reaches the value at which the wave functions of the electron vacancies overlap, a vacant zone of nonlocalized states appears, and the charge allowing noncontact transmission of ions drains quickly. In other words, the capillary closes.
Experimental study of electron beam reflection from a single planar surface of Plexiglas was made. The distinct guiding effect for the part of the beam was observed for 10 keV electrons within angles ...of incidence from 0 to +3 degrees. The experiments using Poly plates showed a number of features of the process such as the dependence of the reflection on the plate surface quality and material of the surfaces, the divisions of the beam into two parts with different behaviour depend on tilt angle and the beam current value, the effect of an elevation angle of the beam in compare with initial beam trace at negative and zero tilt angles of the plate.
We review the status of the Lake Baikal Neutrino Experiment. Preparation towards a km3-scale Gigaton Volume Detector (GVD) in Lake Baikal is currently a central activity. As an important milestone, a ...km3-prototype string comprising 6 optical modules and based on a completely new technology, has been installed and was put into operation together with NT200+ in April, 2008. An upgraded version of the prototype string, which comprises 12 optical modules, was put into operation in April 2009. We also present new results from the long-term operation of NT200, including an improved limit on the diffuse astrophysical neutrino flux.
In this article we describe the main results of the study of prepulses and late pulses in the 8″ Electron Tubes series of photomultipliers. Photomultipliers with large hemispherical photocathodes are ...used widely in many large-scale underground and underwater experiments where precision timing plays a crucial role. The measurements carried out with the aim of demonstrating importance of PMT timing in the context of prepulses and late pulses.
A multipurpose deep-water experimental string has been developed for testing new promising techniques and performing methodical tasks of deep-water muon and neutrino detection in Lake Baikal. The ...design of the setup is described, and some experimental results obtained with the pilot sample of the string under field conditions on Lake Baikal are presented.
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