Collimator diameters

The synchrotron parameters were wiggler field, 5T current, 280 mA energy 2GeV wavelength, 0.876 A. Crystal to film distance, 170 mm. Collimator diameter, 300 p.m. Resolution at the edge of the film was 2.6 A. From Fox et a I (1987) with permission. 

The electron microscope operates under high vacuum. The electron beam in a conventional TEM is stationary. The beam is, by appropriate adjustment of the condenser lenses, highly collimated (diameter of 5 nm) and is allowed to scan over the specimen... 

These problems can be overcome by a careful choice of collimator diameter and positioning of the source and UUT with respect to the collimator, but the necessary algorithms are not simple, and our options are limited. 

The experiment was carried out by a continuously working Nd YAG-laser fabricated by NEC. The laser has a maximum output of 1200 W and is controlled by handling facility with a linear axle. A stage index fiber optical waveguide with a diameter of d=1000 pm was used for the control of the beam. The focusing optics consist of a focusing lens (f=l 16 mm) and a collimation lens (f=70 mm). 

Dimensional measurement using lasers is illustrated by measurement of wire diameter. When a fine wire is inserted in the highly collimated beam of a laser, the light is diffracted by the wire to form a distinct line of spots perpendicular to the length of the wire. The spots appear at angles 9 with respect to the direction of the laser beam. 9 is given by... 

In the normal runs one irradiates the total volume over the leak. Provisions are also made for placing a collimating slit between the leak and the alpha source. The collimating slit was cut in a turret of 6-mm. diameter which screwed onto a leak-carrying cone provided with threads. The slit was elevated over the plane of the leak by unwinding the turret a certain number of revolutions. 

After the preamplifier, the beam is expanded to 2 mm, collimated and imaged onto a 1 mm aperture, producing a flat-top intensity profile. A 3-element telescope relays the aperture plane to the amplifier with a collimated 0.5-mm diameter. The telescope contains a spatial filter pinhole. The nominal power levels are 3 mW into the preamp, 500 mW out of the preamp and 200 mW out of the aperture. A 6° angle of incidence bounce beam geometry is utilized in the amplifier cell. The "bounce" foofprinf overlaps with the 4 pump beam fibers, arranged in 2 time sefs of 13 kHz. The pump fibers have f 50-60% fransmission. The amplifier brings the power up to < 20 W at 26 kHz. 

Fig. 3.15 Left External view of the MIMOS II sensor head (SH) with pyramid structure and contact ring assembly In front of the Instrument detector system. The diameter of the one Euro coin is 23 mm the outer diameter of the contact-ring is 30 mm, the inner diameter is 16 mm defining the field of view of the Instrument. Right. Mimos II SH (without contact plate assembly) with dust cover taken off to show the SH Interior. At the front, the end of the cylindrical collimator (with 4.5 mm diameter bore hole) Is surrounded by the four SI-PIN detectors that detect the radiation re-emltted by the sample. The metal case of the upper detector is opened to show its associated electronics. The electronics for all four detectors Is the same. The Mossbauer drive is inside (in the center) of this arrangement (see also Fig. 3.16), and the reference channel is located on the back side In the metal box shown In the photograph...

Fig. 3.10. Reaction cell. 1 - Atom gun 2 - Thermostate 3 - Metal evaporator 4 - Pt/Pt-Rh thermocouple 5/7 - Collimation holes (diameter 3 mm) 8 -Shutter 9 - ZnO semiconductor sensor 10 - Mobile quartz weight 11 - Platinum contacts terminals 12 - Vitrificated iron bars controlled by a magnet 13 -Quartz guides...

Cylindrical lead collimators with 10 mm thick walls and a clear aperture of about 10 mm diameter were placed between the pin-hole and the X-ray output window of the main chamber to reduce scattered photon noise inside the vacuum chamber. Also, a set of magnets (with typical magnetic field strength of about 1 T) were placed inside each tube to stop high-energy electrons. All these measures were adopted to reduce as much as possible X-rays produced... 

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