The initial beam diameter (4 mm) was reduced to 80 Î¼m. However, this spatial resolution is not high enough. To focus beam more, a small positron source should be fabricated. In this work, we developed a positron microbeam by a small source, a solid neon moderator, magnetic lenses and a SEM optics. In addition, a beam pulsing system was also developed which allows the positron annihilation lifetime spectroscopy (PALS) measurement.
The first American to orbit the Earth, John Glenn made history again when, at the age of 77, he became the oldest person to travel in space. But before he was nationally recognized as a hero, he had put his life on the line for his country many times.
Laika Biography. Laika the dog was the first living being to orbit the Earth in space. She was aboard Sputnik II when it was launched by the Soviet Union on 3 November 1957.