High quality machining of non-metals with a picosecond laser

Author(s):  
B. R. Campbell ◽  
J. A. Moore ◽  
T. M. Lehecka ◽  
J. G. Thomas ◽  
V. V. Semak
2017 ◽  
Vol 24 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Sergey Terentyev ◽  
Maxim Polikarpov ◽  
Irina Snigireva ◽  
Marco Di Michiel ◽  
Sergey Zholudev ◽  
...  

Linear parabolic diamond refractive lenses are presented, designed to withstand high thermal and radiation loads coming from upgraded accelerator X-ray sources. Lenses were manufactured by picosecond laser treatment of a high-quality single-crystal synthetic diamond. Twelve lenses with radius of curvature at parabola apex R = 200 µm, geometrical aperture A = 900 µm and length L = 1.5 mm were stacked as a compound refractive lens and tested at the ESRF ID06 beamline. A focal spot of size 2.2 µm and a gain of 20 were measured at 8 keV. The lens profile and surface quality were estimated by grating interferometry and X-ray radiography. In addition, the influence of X-ray glitches on the focusing properties of the compound refractive lens were studied.


2015 ◽  
Vol 119 (4) ◽  
pp. 1237-1243 ◽  
Author(s):  
Christian Freitag ◽  
Margit Wiedenmann ◽  
Jan-Philipp Negel ◽  
André Loescher ◽  
Volkher Onuseit ◽  
...  

2020 ◽  
Author(s):  
Daniel Holder ◽  
Rudolf Weber ◽  
Christoph Röcker ◽  
Gerhard Kunz ◽  
David Bruneel ◽  
...  

2020 ◽  
Vol 175 (7-8) ◽  
pp. 627-639
Author(s):  
Wenjun Wang ◽  
Aifei Pan ◽  
Tianqi Li ◽  
Rongheng Li ◽  
BenQ Li ◽  
...  

2017 ◽  
Vol 45 (9) ◽  
pp. 554
Author(s):  
Junichi NISHIMAE ◽  
Masashi YOSHIMURA ◽  
Yusuke MORI ◽  
Yosuke ORII

1966 ◽  
Vol 24 ◽  
pp. 51-52
Author(s):  
E. K. Kharadze ◽  
R. A. Bartaya

The unique 70-cm meniscus-type telescope of the Abastumani Astrophysical Observatory supplied with two objective prisms and the seeing conditions characteristic at Mount Kanobili (Abastumani) permit us to obtain stellar spectra of a high quality. No additional design to improve the “climate” immediately around the telescope itself is being applied. The dispersions and photographic magnitude limits are 160 and 660Å/mm, and 12–13, respectively. The short-wave end of spectra reaches 3500–3400Å.


Author(s):  
R. L. Lyles ◽  
S. J. Rothman ◽  
W. Jäger

Standard techniques of electropolishing silver and silver alloys for electron microscopy in most instances have relied on various CN recipes. These methods have been characteristically unsatisfactory due to difficulties in obtaining large electron transparent areas, reproducible results, adequate solution lifetimes, and contamination free sample surfaces. In addition, there are the inherent health hazards associated with the use of CN solutions. Various attempts to develop noncyanic methods of electropolishing specimens for electron microscopy have not been successful in that the specimen quality problems encountered with the CN solutions have also existed in the previously proposed non-cyanic methods.The technique we describe allows us to jet polish high quality silver and silver alloy microscope specimens with consistant reproducibility and without the use of CN salts.The solution is similar to that suggested by Myschoyaev et al. It consists, in order of mixing, 115ml glacial actic acid (CH3CO2H, specific wt 1.04 g/ml), 43ml sulphuric acid (H2SO4, specific wt. g/ml), 350 ml anhydrous methyl alcohol, and 77 g thiourea (NH2CSNH2).


Author(s):  
A. V. Crewe ◽  
J. Wall ◽  
L. M. Welter

A scanning microscope using a field emission source has been described elsewhere. This microscope has now been improved by replacing the single magnetic lens with a high quality lens of the type described by Ruska. This lens has a focal length of 1 mm and a spherical aberration coefficient of 0.5 mm. The final spot size, and therefore the microscope resolution, is limited by the aberration of this lens to about 6 Å.The lens has been constructed very carefully, maintaining a tolerance of + 1 μ on all critical surfaces. The gun is prealigned on the lens to form a compact unit. The only mechanical adjustments are those which control the specimen and the tip positions. The microscope can be used in two modes. With the lens off and the gun focused on the specimen, the resolution is 250 Å over an undistorted field of view of 2 mm. With the lens on,the resolution is 20 Å or better over a field of view of 40 microns. The magnification can be accurately varied by attenuating the raster current.


Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).


Sign in / Sign up

Export Citation Format

Share Document