Bunch by Bunch Feedback and Diagnostics at BESSY II

At the light source BESSY II new digital bunch bybunch feedback systems [1] have been put into operation in January 2013, replacing the existing analog as well as the obsolete digital systems. From the first days of operation the new system successfully suppresses transverse and longitudinal beam instabilities in wide range of machine parameters. The system offers also many new diagnostics opportunities. In this contribution first operational experience, the developed data analysis techniques and experimental data will be presente

Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth

The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids

Booster Fillpattern Monitor

The Booster Fillpattern Monitor is used to measure currents in each individual electron bunch in the booster of the BESSY II machine. The booster with its circumference of 96 meters has space for max.160 electron bunches. The distance between the electron bunches of 60cm 96m 160 is determined by the RF Master Clock 499, 627MHz. In practice, fill patterns of a one to five equally spaced bunches are in use. The fill pattern monitor digitizes electrical pulses generated from a strip line using a broadband ADC. The sampling frequency is selected as an integer fraction of the bunching frequency, acquiring the full fill pattern over a number of turns. Experiments performed at BESSY II demonstrate the performance of the setup and will be discusse

Bunchview A fast and accurate bunch by bunch current monitor

Bunch View is a system for the direct measurement of the current from each bunch circulating in a storage ring based on the analysis of the RF signals delivered by a set of striplines. This paper describes the development, achievements, operation, and results of this fast and accurate bunch current monitor built for the BESSY and MLS storage rings. Using a combination of a 14 16Bit analog to digital converter ADC , a high speed FIFO, ECL technique, and FPGAs, a real time measurement of the fill pattern with high accuracy and bunch by bunch resolution was achieved. The results are identical to the fill pattern determined by time correlated single photon counting based on synchrotron radiation detected with an avalanche photo diode. BunchView is fully integrated into the EPICS control system. The data provided by the BunchView monitor give accurate bucket position in the ring and bunch current over a wide dynamic range. The smallest measured single bunch current is less than 100nA. In the future the system will be used in the top up mode of operation in order to inject beam into the emptiest buckets and thus keep the fill pattern stable over longer periods of time

Severe Emphysema Treated by Endoscopic Bronchial Volume Reduction with Lung Sealant (AeriSeal)

Endoscopic lung volume reduction using lung sealant is a very new and innovative treatment option for patients with severe progressive and irreversible lung emphysema. A 55-year-old ex-smoker (60 pack years) referred to our center because of severe lung emphysema with progressive worsening of the obstructive ventilator pattern and clinical condition. We detected collateral channels of this patient by using the Chartis system. Therefore, we decided to treat the advanced emphysema of our patient with endoscopic volume reduction using lung sealant (AeriSeal). The foam of lung sealant AeriSeal is instilled into the peripheral airways and alveoli where it polymerizes and functions as tissue glue on the lung surface in order to seal the target region to cause durable irreversible absorption atelectasis. The follow-up evaluation 12 weeks later showed improved lung function (increased FEV 1/partial oxygen pressure/peripheral oxygen saturation and a reduction of TLC and RV) with improved quality of life. Correlation between changes in primary and secondary outcome measures in the lung function parameters and 6-minute-walking test before and 12 weeks after the application of lung sealant revealed significant reduction of hyperinflation and improvement both in the flow rates and in the physical capability of this patient