Richard D. Deslattes.

On May 16, 2001, the National Institute of Standards and Technology lost a most illustrious career scientist in x-ray research. This volume is dedicated to honor the memory of Richard D. Deslattes and his lifetime of achievements at NIST. Deslattes' research in precision metrology, interferometry, and x-ray spectroscopy earned him worldwide recognition. Much of his research was directed toward the determination of fundamental physical constants and masses of elementary particles, and toward testing basic theories. Deslattes was the first to combine x-ray and optical interferometry, and in a famous experiment he used the remarkable instrument he created to link x-ray light to visible light and to precisely determine the spacing of atoms in a silicon crystal. This measurement was a key input needed to obtain an improved value for the Avogadro constant, a fundamental constant of nature related to the amount of substance, and which may one day lead to a new natural standard of mass. Deslattes also used the atom s pacing measurement to establish more accurate x-ray and gamma ray wavelength standards. He played a major role in the development of the iodine stabilized laser, a precise light source that was a significant step in the evolution of the international standard for the meter. Deslattes was also well known for novel applications of x-ray diffraction. One of these applications was a precision calibration device that allowed radiologists to record better quality mammograms. His enormous energy, his ability to lead, and his remarkable creativity will be deeply missed.

Ernest Kessler

Gabrielle Long