Showing papers by "Varian Associates published in 2007"

Performance of new ceramic scintillators for gamma- and x-ray detection

Abstract: Ceramic materials show significant promise for the production of reasonably priced, large-size scintillators. Ceramics have recently received a great deal of attention in the field of materials for laser applications, and the technology for fabricating high-optical-quality polycrystalline ceramics of cubic materials has been well developed. The formation of transparent ceramics of non-cubic materials is, however, much more difficult as a result of birefringence effects in differently oriented grains. Here, we will describe the performance of a few new ceramics developed for the detection of gamma- and x-ray radiation. Results are presented for ceramic analogs of three crystalline materials - cubic Lu 2 O 3 , and non-cubic LaBr 3 , and Lu 2 SiO 5 or LSO (hexagonal, and monoclinic structures, respectively). The impact of various sintering, hot-pressing and post-formation annealing procedures on the light yield, transparency, and other parameters, will be discussed. The study of LaBr 3 :Ce shows that fairly translucent ceramics of rare-earth halides can be fabricated and they can reach relatively high light yield values. Despite the fact that no evidence for texturing has been found in our LSO:Ce ceramic microstructures, the material demonstrates a surprisingly high level of translucency or transparency. While the scintillation of LSO:Ce ceramic reaches a light yield level of about 86 % of that of a good LSO:Ce single crystal, its decay time is even faster, and the long term afterglow is lower than in LSO single crystals.

Probes for High Resolution

Abstract: The sections in this article are 1 Introduction 2 Historical Review 3 Modern Probe Technology 4 Conclusions 5 Biographical Sketch Related Articles

Packard, Martin E.: Nuclear Induction at Stanford and the Transition to Varian

Abstract: The sections in this article are 1 The Beginning—Early January 1946 2 Prologue 3 The Lull After the First Success 4 The Bloch versus Purcell Method 5 The Scientific Direction of the Laboratory 6 The Beginning of High Resolution 7 High Resolution in Organic Compounds 8 Russell Varian and the Patent 9 Epilogue 10 Biographical Sketch

Shoolery, James N.: High‐Resolution NMR: A Dream Come True

Abstract: The sections in this article are 1 NMR Spectroscopy: In the Beginning (1952–60) 2 The 1960s: Decade of the Technological Breakthroughs 3 The 1970s–The Time Domain 4 The 1980s: No Problem is Too Tough 5 The 1990s and Beyond 6 Biographical Sketch

Anderson, Weston A.: Early NMR Experiences and Experiments

Abstract: The sections in this article are 1 Early Scientific Interests of the Author 2 On to Stanford 3 Working at CERN 4 Varian Associates and the Bloch–Hansen Patent 5 Russ Varian and his Magnetometer 6 High-Resolution NMR Experiments 7 Fourier Transform NMR 8 Then and Now 9 Biographical Sketch

Fourier Transform Spectroscopy

Abstract: The sections in this article are 1 Introduction 2 Historical Background 3 The Mathematics of the Fourier Transform 4 The Bloch Equations 5 The Fourier Transform Spectrometer Electronics 6 Biographical Sketch Related Articles