The interaction and decay of K−-mesons in photographic emulsion

1960 ◽  
Vol 15 (6) ◽  
pp. 873-898 ◽  
Author(s):  
D. Evans ◽  
F. Hassan ◽  
K. K. Nagpaul ◽  
D. J. Prowse ◽  
M. René ◽  
...  
Keyword(s):  
Photographic Emulsion ◽  
K Mesons

On the emission of fast ∑ -hyperons from disintegrations due to the capture of K - -mesons by light nuclei

1961 ◽  
Vol 262 (1308) ◽  
pp. 73-83 ◽  
Keyword(s):  
Light Nucleus ◽  
Light Nuclei ◽  
Photographic Emulsion ◽  
K Mesons

A study has been made of those disintegrations produced in photographic emulsion by the nuclear capture at rest of K - -mesons, from which fast charged ∑ -hyperons are emitted. In a sample of 63 events, six were analyzed unambiguously as being due to absorption in carbon, nitrogen or oxygen without the emission of any neutrons. An additional eight were found to be consistent with capture by a light nucleus with the emission of one neutron only in each case. The fraction of disintegrations due to K - -meson capture in light nuclei from which a fast charged ∑ -hyperon is emitted has been estimated.

The interaction of K−-mesons with photographic emulsion nuclei

1959 ◽  
Vol 14 (2) ◽  
pp. 315-364 ◽  
Author(s):  
B. Bhowmik ◽  
D. Evans ◽  
D. Falla ◽  
F. Hassan ◽  
A. A. Kamal ◽  
...  
Keyword(s):  
Photographic Emulsion ◽  
K Mesons

The interaction and decay of K− mesons in photographic emulsion

1959 ◽  
Vol 13 (4) ◽  
pp. 690-729 ◽  
Author(s):  
B. Bhowmik ◽  
D. Evans ◽  
D. Falla ◽  
F. Hassan ◽  
A. A. Kamal ◽  
...  
Keyword(s):  
Photographic Emulsion ◽  
K Mesons

The interactions of positive k-mesons with nuclei in photographic emulsion at energies in the region 0 ÷ 30 MeV

1957 ◽  
Vol 6 (3) ◽  
pp. 440-477 ◽  
Author(s):  
B. Bhowmik ◽  
D. Evans ◽  
S. Nilsson ◽  
D. J. Prowse ◽  
F. Anderson ◽  
...  
Keyword(s):  
Photographic Emulsion ◽  
K Mesons

Preliminary results on the interactions in photographic emulsion of K−-mesons at 1.15 GeV/c

1960 ◽  
Vol 16 (6) ◽  
pp. 1135-1138 ◽  
Author(s):  
L. Culhane ◽  
D. Keefe ◽  
A. Kernan ◽  
J. Losty ◽  
A. Montwill
Keyword(s):  
Photographic Emulsion ◽  
Preliminary Results ◽  
K Mesons

The interactions of positive K-mesons with nuclei in photographic emulsion at energies in the region (240÷300) MeV

1959 ◽  
Vol 12 (3) ◽  
pp. 241-263 ◽  
Author(s):  
D. Keefe ◽  
A. Kernan ◽  
A. Montwill ◽  
M. Grilli ◽  
L. Guerriero ◽  
...  
Keyword(s):  
Photographic Emulsion ◽  
K Mesons

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

One Million Direct Magnification Microscopy

1971 ◽  
Vol 29 ◽  
pp. 166-167
Author(s):  
J. A. Hugo ◽  
V. A. Phillips
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Illumination Level ◽  
Level Of Detail ◽  
Photographic Emulsion ◽  
Low Contrast ◽  
Fluorescent Screen ◽  
Resolution Electron ◽  
Lattice Images ◽  
Electron Microscopes

A continuing problem in high resolution electron microscopy is that the level of detail visible to the microscopist while he is taking a picture is inferior to that obtainable by the microscope, readily readable on a photographic emulsion and visible in an enlargement made from the plate. Line resolutions, of 2Å or better are now achievable with top of the line 100kv microscopes. Taking the resolution of the human eye as 0.2mm, this indicates a need for a direct viewing magnification of at least one million. However, 0.2mm refers to optimum viewing conditions in daylight or the equivalent, and certainly does not apply to a (colored) image of low contrast and illumination level viewed on a fluorescent screen through a glass window by the dark-adapted eye. Experience indicates that an additional factor of 5 to 10 magnification is needed in order to view lattice images with line spacings of 2 to 4Å. Fortunately this is provided by the normal viewing telescope supplied with most electron microscopes.

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Shot-noise simulations of HREM images of polymer crystals

1989 ◽  
Vol 47 ◽  
pp. 342-343
Author(s):  
Philippe Pradère ◽  
Edwin L. Thomas
Keyword(s):  
Low Dose ◽  
Molecular Level ◽  
High Resolution Electron Microscopy ◽  
Crystal Defects ◽  
Inorganic Materials ◽  
Photographic Emulsion ◽  
Polymer Crystals ◽  
Resolution Electron ◽  
Recent Developments ◽  
Lattice Images

High Resolution Electron Microscopy (HREM) is a very powerful technique for the study of crystal defects at the molecular level. Unfortunately polymer crystals are beam sensitive and are destroyed almost instantly under the typical HREM imaging conditions used for inorganic materials. Recent developments of low dose imaging at low magnification have nevertheless permitted the attainment of lattice images of very radiation sensitive polymers such as poly-4-methylpentene-1 and enabled molecular level studies of crystal defects in somewhat more resistant ones such as polyparaxylylene (PPX) [2].With low dose conditions the images obtained are very noisy. Noise arises from the support film, photographic emulsion granularity and in particular, the statistical distribution of electrons at the typical doses of only few electrons per unit resolution area. Figure 1 shows the shapes of electron distribution, according to the Poisson formula :

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