Particle accelerators in Mexico

2006 ◽  
Vol 36 (2) ◽  
pp. 297-309
Author(s):  
MARÍÍA DE LA PAZ RAMOS LARA

ABSTRACT The first Van de Graaff particle accelerator in Latin America was installed at the Universidad Nacional Autóónoma de Mééxico (UNAM) in 1952. This event marked the beginning of experimental nuclear physics, exclusively for peaceful purposes, in Mexico. The acquisition of this accelerator was fundamental for placing other accelerators into operation, which were used for both research and the resolution of national problems.

Author(s):  
K. F. Russell ◽  
L. L. Horton

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.


2014 ◽  
Vol 27 ◽  
pp. 1460147 ◽  
Author(s):  
BIBHUDUTTA ROUT ◽  
MANGAL S. DHOUBHADEL ◽  
PRAKASH R. POUDEL ◽  
VENKATA C. KUMMARI ◽  
WICKRAMAARACHCHIGE J. LAKSHANTHA ◽  
...  

The University of North Texas (UNT) Ion Beam Modification and Analysis Laboratory (IBMAL) has four particle accelerators including a National Electrostatics Corporation (NEC) 9SDH-2 3 MV tandem Pelletron, a NEC 9SH 3 MV single-ended Pelletron, and a 200 kV Cockcroft-Walton. A fourth HVEC AK 2.5 MV Van de Graaff accelerator is presently being refurbished as an educational training facility. These accelerators can produce and accelerate almost any ion in the periodic table at energies from a few keV to tens of MeV. They are used to modify materials by ion implantation and to analyze materials by numerous atomic and nuclear physics techniques. The NEC 9SH accelerator was recently installed in the IBMAL and subsequently upgraded with the addition of a capacitive-liner and terminal potential stabilization system to reduce ion energy spread and therefore improve spatial resolution of the probing ion beam to hundreds of nanometers. Research involves materials modification and synthesis by ion implantation for photonic, electronic, and magnetic applications, micro-fabrication by high energy (MeV) ion beam lithography, microanalysis of biomedical and semiconductor materials, development of highenergy ion nanoprobe focusing systems, and educational and outreach activities. An overview of the IBMAL facilities and some of the current research projects are discussed.


1960 ◽  
Vol 82 (6) ◽  
pp. 1517-1518 ◽  
Author(s):  
Arthur Roberts

1968 ◽  
Vol 36 (11) ◽  
pp. 987-993 ◽  
Author(s):  
Paul A. Treado ◽  
James M. Lambert

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