Improvements of the Set Up and Procedures for Beam Energy Measurements at BESSY II

With a 7 T wiggler in operation all attempts to detect the resonant depolarization of the electron spins were unsuccessful at BESSY II. This was attributed to the severely reduced degree of spin polarization of the electrons moving in the alternating fields of the strong wiggler which on the other hand nearly doubles the radiation loss per turn. The key to a clear detection of the depolarization is the improvement of the sensitivity of the polarimeter, based on the spin dependent Touschek scattering cross section and the more effective and thus full depolarization of the beam. With these improvements the high precision beam energy determination can again be performed in parallel to the normal user operation and without any noticeable perturbations to the bea

Novel C-terminal heat shock protein 90 inhibitors target breast cancer stem cells and block migration, self-renewal, and epithelial–mesenchymal transition

In patients with triple-negative breast cancer (TNBC), evidence suggests that tumor-initiating cells (TIC) have stem cell-like properties, leading to invasion and metastasis. HSP90 plays a critical role in the conformational maintenance of many client proteins in TIC development. Therefore, we hypothesize that the novel C-terminal HSP90 inhibitors KU711 and KU758 can target TIC and represent a promising strategy for overcoming metastasis. Human breast cancer cells (MDA-MB-468LN, MDA-MB-231) treated with the HSP90 inhibitors KU711, KU758, and 17-AAG showed a 50–80% decrease in TIC markers CD44 and aldehyde dehydrogenase (P < 0.01) as assessed by flow cytometry. A decrease in sphere formation, which was used to assess self-renewal, was observed after the treatment of TNBC cells starting at 2.5 µm KU711 and 0.31 µm KU758. KU compounds also blocked the invasion and migration of TNBC cells in a dose-dependent manner. The knockdown of HSP90 clients was observed without any change in prosurvival HSP70 levels. In vivo, in a murine orthotopic breast cancer model, treatment with KU758 and KU711 yielded an approximately twofold and a fourfold reduction in tumor volumes versus control, respectively, without demonstrated toxicity. In conclusion, C-terminal HSP90 inhibitors are potent novel therapeutics against TNBC in vitro and in vivo as they target TICs and block invasion, EMT transition, and self-renewal

First Prototype of a Coronagraph based Halo Monitor for BERLinPro

Since particle losses by beam halo induced by space charge force and scattering of trapped ions are critical issues for superconducting linac based high power machines such as bERLinPro, a halo monitor is demanded to monitor and control particle distribution at the level of 10 amp; 1048576;4 10 amp; 1048576;5 of the core intensity. A coronagraph based halo monitor was adopted and the first prototype has been designed as a demonstrator system aimed at resolving a halo core contrast in the 10 amp; 1048576;3 to 10 amp; 1048576;4 range. This monitor was tested at BESSY II with various operation modes such as Transverse Resonance Island Buckets TRIBs and Pulse Picking by Resonant Excitation PPRE . We show our design parameters, experimental criterion, and experimental result

Coronagraph Based Beam Halo Monitor Development for BERLinPro

For linac based high power electron machines, beam halo induced by nonlinear space charge force and scattering of trapped ions is one of the critical issues on a machine protection system. It causes additional radiation which can be a heat source on a cryogenic system as a result of uncontrolled beam losses. During the last decades, several instruments have been newly developed for measuring the beam halo distribution. The conceptual design and optimization of the coronagraph based halo monitor were performed to measure the beam halo which has amp; 8764; 10 amp; 8722; amp; 1049815; contrast to the beam cor

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