Band 2 / Claude Cohen-Tannoudji, Bernard Diu, Franck Laloë — 3. A , , Optoelektronika pro telekomunikace a informatiku / Miloslav Filka — Vyd. STK, F z, , Automatické řízení pro bakaláře / Pavel Zítek — Vyd. .com/ company/optronic-gesellschaft-fur-optoelektronik-u-kommunikationstechnik-mbh/ -. == MTA4MA== == .. == .
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Thank you for your participation! Reproduciton only with permission of the Editor and under observing the bbernard. Unasked manuscripts are not sent back. The authors are responsible for originality and correctness of their contributions. Annual fee is ,- CZK.
This price of subscription is the same for both Czech and Slovac Republics. Contact place for the Slovak Republic: Price for optkelektronika copy: Literatura  American Society of Metals. Welding and brazing, Vol.
Mechanical properties of the Cu-Be alloys and the welded joints. Research report, Palacky University, not published. Study of the microstructures of the different welded materials. Using of electron beam welding in the branch of the instruments techniques. We would like to apply our experiences with producing and bsrnard of the mirror type in atmospheric detectors of ultra high energy cosmic rays for the LIDAR optical system.
JEMNÁ MECHANIKA A OPTIKA
To minimize the atmospheric uncertainties, these experiments are located in dry desert areas with typically excellent atmosphere visibility. However the atmosphere in these areas is not stable enough during whole year and during the nights. So that optoelektronkka calibration of the atmospheric attenuation will be necessary to reconstruct the shower profiles . Light emitted by laser interacts with the target.
The Mechanical Systems Design Handbook: Modeling, Measurement, and Control – PDF Free Download
One part of this light is scattered back to the detection device whe- 8 re it is analyzed. The change in the properties of the light reflects certain target properties. The time when is light traveling to the target and back to the LIDAR is used to determine the target distance or attenuation distance dependency.
LIDAR has much usage in measuring technology, for example it is possible to locate defects or unhomogeneities in optical fibers, to measure distance, speed, rotation, chemical composition and concentration of a remote target, where the target optoelektronikaa be a sharp defined object, or a diffuse object such a cloud or atmosphere.
The light source is frequency tripled Optielektronika YAG laser base wavelength nmwhich is able to emit up optoele,tronika 20 pulses per second, each with energy of 7mJ and 4ns duration spatial pulse length 1.
The laser divergence is 3mrad and the emitted wavelength nm is in the range of the nitrogen fluorescence spectrum nm. The distance between laser optoelektronuka and the mirror center is 1m, and the entry point of the laser beam into the telescope field of view is at the distance m.
The signal is digitized using a ooptoelektronika Licel transient recorder TR with 12bit resolution at 40MHz sampling rate . A principal layout is on the figure1. The aberration of the spherical mirror with diameter 1m is big and therefore it is necessary to use the segments  for the mirror with this diameter. If the mirror is segmented, we can use ultralight segments without reflecting surface deformation and lability, this mirror has minimal mass and requires minimal demands for the construction, which must be able to turn.
Another crucial requirement is the spot diameter an image of a point source in opotelektronika. The detector is one photomultiplier with input aperture diameter 10mm. For that reason there is not so strict requirement for resolution, acceptable resolution angle is about 0. The optimal solution should be parabolic mirror, but making the mirror with this diameter is technically demanding and more expensive then spherical mirrors production.
The spherical shape implies a spherical aberration and a spot is not a point, but a disc. The mirror with basic spherical shape, diameter 1 m and radius of curvature 2. The usage of the Davies-Cotton mirrors system the eight side mirrors are shifted and turned, but the radiuses of the side and central mirrors are the same 2.
If our special mirror design is used radiuses are not equal beernard side mirrors are behind the central mirrorthis spot size will be reduced. We use the design with one central circular mirror diameter mm and curvature radius mm and eight side segments curvature radius mm which form a sphere zone and they are turned through 0. We made several configuration simulations, for example with eight or twelve side mirrors.
However the spot size decreases imperceptibly and the number of central holes and spaces increase, hence the efficiency decreases. Furthermore, the production and mechanical construction would be more complicated. This value is very good for this type of the thin glass mirrors thickness mm.
So the final resolution will be 0.
For this configuration an angular image size of the laser trace will have: It follows that the laser trace image is 8. With this image size and 10mm PMT aperture diameter this configuration will operate well above 1km, because the whole image is projected into the PMT aperture. For some lower elevation measuring or with using a smaller PMT aperture for background noise elimination by field of view reduction — optimal will be 0.
It is a reflecting surface similar to a paraboloid, which is attached to the PMT aperture. This concentrator is able to concentrate energy into the small aperture form the selected field of view.
Our production process includes coating layers on polished glass. The reflecting surface of the mirror is an aluminium layer with a protection silica layer. This mirror has minimal mass and it give in the segmented construction good performance with usage minimal financial resources.
However it is necessary to pay close attention to the thermal expansivity and rigidity of the mechanism, because the system is very sensitive to misalign. References  The Auger Collaboration: Pierre Auger Project Design Report. Atmospheric Monitoring for the Auger Fluorescence Detector. Proceedings of ICRC p.
The Mechanical Systems Design Handbook: Modeling, Measurement, and Control
Light mirrors for VHE astronomy telescopes. Several setups were designed to measure fluorescent and Cherenkov light. In this paper we report those of them designed by the Czech group participating in the project. The observatory consists of several fluorescence telescopes and an array of surface water detectors. The task for fluorescence detectors is to detect the feeble fluorescence light optoelekhronika by nitrogen molecules excited by collision with cosmic rays of very high energy in high level atmosphere at the altitude up to 20 km.
This process is also accompanied by the Cherenkov emission which has its characteristic forward anisotropy. The spectrum of the fluorescence light falls within — nm range.
The knowledge of the fluorescence emission efficiency is the relevant contribution to the absolute energy calibration which is essential brrnard the Pierre Auger experiment and others concerning with the task of high energy cosmic rays with the aid of fluorescence detectors. For the first time, the mechanism of atmospheric fluorescence beenard described by Blummer in his Ph. High energy particles, particularly electrons or positrons, are generated by linear accelerator LINAC.
So the collection of generated fluorescence light is one of the most important tasks while the design of a fluorescence chamber is proposed. There have been two designs proposed by the Czech group to detect the fluorescence light or the Cherenkov light. Elliptical-mirror design An elliptical-mirror chamber , Figure 3, has been proposed for the purpose of fluorescence measurement where the light collection maximalization is required.
There are several advantages of the concave mirror to condenser lenses. First, the mirror has better collection efficiency than the condensor lens and it is not spectral dependent which is especially important while the detected light is in the UV region there is a need of an expensive condenser optoelektronikaa, quartz for instance, in the case of lenses. In this case we used elliptical mirror with major semi-axis of 80 mm, minor semi-axis of 60 mm and mm in length. The chamber is designed so that the particle beam passes the mirror in one of its focus lines.
The area of the fluorescence emission tracks the beam so it acts as a linear isotropic light source. The mirror collects the emitted light in its second focal line where the linear fiber bundle is befnard to bring the light to the photomultiplier PMT which is Photonics XP 2 inch input aperture in this case. Plastic optical fibers were used to collect the light because of high numerical aperture and plasticity.
A disadvantage of this fiber is its lower transmittance in the UV region, though the fiber length is small. While tested a significant increase in the light collection was observed — a factor 10 with respect to the basic fluorescence chamber designed for the project . The drawback of the elliptical-mirror design is its high sensitivity to the position of the particle beam. Two-paddles chamber The two-paddles chamber, Figure 4, has been proposed for the measurement of the anisotropic forward Cherenkov light emitted along with the fluorescent light.
The paddles were made of plexi material PMMA and both of them were 8 mm in width.
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This arrangement has been allowed to be less sensitive to a beam position variation. This assumption was tested along with the intensity scan. The measurement setup is shown in Figure 5.
In this arrangement, a beam of high energy electrons went from the tail pipe of the LINAC and developped towards the calorimeter where it was absorbed. The beam passed successively through a chamber with three photomultipliers to detect the fluorescence light, a Cherenkov chamber containing a mylar mirror to collect Cherenkov light and the two-paddles chamber. The test results of the chamber are described in . Figure 6 shows one the most interesting — the result of the dependence of photomultipliers outputs to the horizontal position of the beam the x-scan test.
The measurement was carried out with the energy MeV of the electron beam. The channel adc15 corresponds to the 12 Fig. As we can see from this figure, the outputs of the photomultipliers have inverted curves with extremes a minimum in the first case and a maximum in the latter one which are close each to other for the deflecting current A.
The sum of both outputs is depicted in the fourth graph. It can be approximated by a multinomial of the first degree. From the gradient of the curve it is obvious that the first photomultiplier catch the most part of the response to the beam. Note the fine Gauss distribution of the calorimeter the channel adc16 for the x-scan as depicted in the third graph of the Figure 6. OUTLOOK After one year of designing and testing of several types of fluorescence and Cherenkov chambers, the AIRFLY team has proposed a final design of the chamber for an absolute measurement of the fluorescence yield and the detailed measurement of the fluorescence spectrum.