scholarly journals Mechanical Metallurgy of Plutonium Metal, Alloys, and Allotropes

2020 ◽  
Author(s):  
Michael Francis Stevens
Keyword(s):  
Metal Alloys ◽  
Mechanical Metallurgy ◽  
Plutonium Metal

Microscopy and Microanalysis of Plutonium Metal, Alloys and Oxides or the Problem With Pu

2000 ◽  
Vol 6 (S2) ◽  
pp. 932-933
Author(s):  
Rollin E. Lakis ◽  
Bradford G. Storey ◽  
Charles C. Davis
Keyword(s):  
Atomic Number ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Pure Metal ◽  
University Of California ◽  
Metal Alloys ◽  
Naturally Occurring ◽  
The University ◽  
Crystalline Forms ◽  
Plutonium Metal

Plutonium (Pu), with an atomic number of 94, is the highest atomic number naturally occurring element on Earth. It is formed when naturally occurring Uranium 238 captures a neutron that can be created by spontaneous fission and alphaneutron reactions. The natural abundance of terrestrial Pu is very small; its concentration is about one part in 10 of the uranium present in naturally occurring uranium ores. The first man-made plutonium was produced at the University of California cyclotron and identified on February 23, 1941. Just a few months after the first Pu was produced it became clear how metallurgically complex this material is. Plutonium is known to have six allotropes (crystalline forms) at atmospheric pressure, between room temperature and 640°C, the melting point of the pure metal. This is the largest number of allotropes known for any element.

Specimen Preparation of Near Surface Ion Irradiated Samples

1985 ◽  
Vol 43 ◽  
pp. 170-171
Author(s):  
K. F. Russell ◽  
L. L. Horton
Keyword(s):  
Radiation Damage ◽  
Heavy Ions ◽  
Target Material ◽  
Metal Alloys ◽  
Specimen Surface ◽  
Specimen Preparation ◽  
Particle Accelerators ◽  
Near Surface ◽  
Graaff Accelerator ◽  
Van De Graaff

Beams of heavy ions from particle accelerators are used to produce radiation damage in metal alloys. The damaged layer extends several microns below the surface of the specimen with the maximum damage and depth dependent upon the energy of the ions, type of ions, and target material. Using 4 MeV heavy ions from a Van de Graaff accelerator causes peak damage approximately 1 μm below the specimen surface. To study this area, it is necessary to remove a thickness of approximately 1 μm of damaged metal from the surface (referred to as “sectioning“) and to electropolish this region to electron transparency from the unirradiated surface (referred to as “backthinning“). We have developed electropolishing techniques to obtain electron transparent regions at any depth below the surface of a standard TEM disk. These techniques may be applied wherever TEM information is needed at a specific subsurface position.

Sign in / Sign up

Export Citation Format

Share Document