A classic example of such a molecule is TIPS-pentacene with a pentacene backbone and two bulky tri-isopropyl silyl ethynyl (TIPS) side groups that render the molecule soluble in toluene. A feature of this class of materials is low lattice symmetry and polymorphism, i.e., depending on the crystallization conditions, different crystal structures and types of molecular packing may form. The distance between the p-orbitals is all-important for device performance - the closer the better.

Due to the demand for longer and larger inner and outer diameter capillaries, a new requirement is the need to measure outer diameters greater than 6 mm. Example projects include requests by the APS transmission x-ray microscope project, Cornell’s X-ray emission spectrometer project and the FDA laser funnel application. To accommodate these requests, a newly purchase Keyence sensor head with monitor, Model LS-7030M will be soon commissioned. It expands our capabilities to profile large outer diameter capillaries up to 30 mm.

On the other hand, long ERL undulators with short periods will generate higher radiation power density on beamline first optics than encountered at 3rd generation sources. We have recently published thermal and strain analyses, and wavefront simulation for cryogenic cooled Si(111) monochromators showing that beam quality within the radiation central cone should be well preserved. This important result depends strongly on very small ERL source emittance in BOTH horizontal and vertical directions, making the undulator central cone very small.

The system was designed with flexibility in mind, allowing for X-ray diffraction experiments to be combined with a wide suite of mechanical tests. Loads are applied to samples by a Bose 3330 testing system capable of applying a max 3000N at a frequency of 100hz for high-cycle fatigue testing. 250lbs (1112N) and 1000lbs (4448N) load cells are available for high and low load amplitude loading. Fixtures are available for tensile, compressive, and fully reversed loading. A furnace capable of heating samples to 1000°C during mechanical loading is also available.

In a recent work, Masayo Suzuki et. al.¹ have reported the development of a high-flux X-ray monitor based upon the scintillation of Ar gas as X-rays pass through it. Unlike ion chambers, where the temporal response is limited by the drift velocity of charged particles in gaseous media, it is possible for Ar-scintillation monitors to yield time resolution better than 50 ns.

At CHESS, we have created a device that uses the same principle as the one mentioned above with the added capability of measuring X-ray beam position, in addition to flux.

Self-made tape measurers hang suspended from the ceiling, stretched to reach the tops of the tables with 10cm increments clearly marked. Kids take turns vertically propelling the balls using student-made ball-launchers. This was the scene in the eXploration station this past month when first graders from Fall Creek Elementary School participated in bimonthly visits to Xraise at Cornell during the past school year. Teachers Chris Bell and Abigail Bokaer brought their students, sometimes riding the bus and sometime walking up the hill, to participate in these science investigations.

Many forward-thinking scientists at synchrotron and newer free-electron laser x-ray facilities are hoping that someday scientists will be able to determine the structure of a single molecule using x-ray techniques. Lacking millions of similar molecules periodically spaced on a crystalline lattice, the x-ray signal from a single molecule will be extraordinarily weak. Still, with the advent of imaging detectors that have very low background noise, it still seems feasible that even a few photons scattered from a single molecule should be sufficient.

RIM experiments at CHESS have reached a degree of complexity that a permanent lab was set up, in which users can test and develop their experimental set-ups as well as can be trained in the use of CHESS sample cells and ancillary equipment. A mock-up of the D1 station sample goniomenter is set up on an optical table (Figure 1) and can be equipped with a sample microscope, an optical spectrometer, or an optical film thickness monitor, so that complex experiments can be prepared and tested, before the equipment is transferred to the beamline.

As of earlier this month, the secret is out: Pablo Picasso’s 1901 masterpiece, “The Blue Room,” part of the Phillips Collection in Washington, D.C., is indeed painted over another painting of a bearded, bow-tied man, according to details released by museum officials.

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"Some Early Synchrotron Radiation History"

Preface