Using an InGrid Detector to Search for Solar Chameleons with CAST

We report on the construction, operation experience, and preliminary background measurements of an InGrid detector, i.e. a MicroMegas detector with CMOS pixel readout. The detector was mounted in the focal plane of the Abrixas X-Ray telescope at the CAST experiment at CERN. The detector is sensitive to soft X-Rays in a broad energy range (0.3--10 keV) and thus enables the search for solar chameleons. Smooth detector operation during CAST data taking in autumn 2014 has been achieved. Preliminary analysis of background data indicates a background rate of $1-5\times 10^{-5}\,\mathrm{keV}^{-1}\mathrm{cm}^{-2}\mathrm{s}^{-1}$ above 2 keV and $\sim 3\times 10^{-4}\,\mathrm{keV}^{-1}\mathrm{cm}^{-2}\mathrm{s}^{-1}$ around 1 keV. An expected limit of $\beta_\gamma \lesssim 5\times 10^{10}$ on the chameleon photon coupling is estimated in case of absence of an excess in solar tracking data. We also discuss the prospects for future operation of the detector.Comment: Contributed to the 11th Patras Workshop on Axions, WIMPs and WISPs, Zaragoza, June 22 to 26, 201

An InGrid based Low Energy X-ray Detector

An X-ray detector based on the combination of an integrated Micromegas stage with a pixel chip has been built in order to be installed at the CERN Axion Solar Telescope. Due to its high granularity and spatial resolution this detector allows for a topological background suppression along with a detection threshold below $1\,\text{keV}$. Tests at the CAST Detector Lab show the detector's ability to detect X-ray photons down to an energy as low as $277\,\text{eV}$. The first background data taken after the installation at the CAST experiment underline the detector's performance with an average background rate of $5\times10^{-5}\,/\text{keV}/\text{cm}^2/\text{s}$ between 2 and $10\,\text{keV}$ when using a lead shielding.Comment: 4 pages, 5 figures, Contributed to the 10th Patras Workshop on Axions, WIMPs and WISPs, CERN, June 29 to July 4, 201

Policymakers follow pertinent academic research, but see much of it as irrelevant to their work

Last year, U.S. Congressman Eric Cantor called for an end to federal funding for political and social science, claiming that the funds could be better spent on medical research. The renewal of this contentious debate begs the important question, what do policymakers ideally want from scholars and their work? To answer this, Paul Avey and Michael Desch surveyed nearly 1000 former national security policymakers and found that while they follow international relations research, the prevalence of jargon as well as the focus on quantitative studies and techniques alienates many of these important readers

Magnetic antenna using metallic glass

A lightweight search-coil antenna or sensor assembly for detecting magnetic fields and including a multi-turn electromagnetic induction coil wound on a spool type coil form through which is inserted an elongated coil loading member comprised of metallic glass material wrapped around a dielectric rod. The dielectric rod consists of a plastic or a wooden dowel having a length which is relatively larger than its thickness so as to provide a large length-to-diameter ratio. A tri-axial configuration includes a housing in which is located three substantially identical mutually orthogonal electromagnetic induction coil assemblies of the type described above wherein each of the assemblies include an electromagnetic coil wound on a dielectric spool with an elongated metallic glass coil loading member projecting therethrough

Killing the cMSSM softly

We investigate the constrained Minimal Supersymmetric Standard Model (cMSSM) in the light of constraining experimental and observational data from precision measurements, astrophysics, direct supersymmetry searches at the LHC and measurements of the properties of the Higgs boson, by means of a global fit using the program Fittino. As in previous studies, we find rather poor agreement of the best fit point with the global data. We also investigate the stability of the electro-weak vacuum in the preferred region of parameter space around the best fit point. We find that the vacuum is metastable, with a lifetime significantly longer than the age of the Universe. For the first time in a global fit of supersymmetry, we employ a consistent methodology to evaluate the goodness-of-fit of the cMSSM in a frequentist approach by deriving p-values from large sets of toy experiments. We analyse analytically and quantitatively the impact of the choice of the observable set on the p-value, and in particular its dilution when confronting the model with a large number of barely constraining measurements. Finally, for the preferred sets of observables, we obtain p-values for the cMSSM below 10%, i.e. we exclude the cMSSM as a model at the 90% confidence level.Comment: 22 pages, 16 figures, to be submitted to EPJ

Movement of layers and induced tension in the nip area between drum and paper layers

During paper manufacture and processing production losses occur during winding of machine-wide paper rolls and finished rolls due to winding faults. During the winding process at least one drum (steel or rubber-covered) is in contact with the winding roll and creates a nip area where tension and shifting of layers are induced. This process in the nip area with several layers of paper is not known in detail but the knowledge would be helpful to improve winding processes

Who punishes the leader? Leader culpability and coups during civil war

Who punishes leaders via coups during civil war? By distinguishing between different types of internal audiences within the government and their attempts to remove a leader forcefully, I illuminate the mechanisms that explain variation in who punishes the leader during wartime. I claim that whether leaders are culpable for the initiation of the war has an important implication for whether they are punished by members of the ruling coalition (i.e., those with access to decision-making and political power), or by those outside the ruling coalition. Empirical evidence supports my hypotheses: (i) culpable leaders are more likely to experience coup attempts led by those outside the leaders' ruling coalition, should the war go poorly; and (ii) nonculpable leaders are more likely to experience coups executed by members of their ruling coalition. The findings have important implications for how leaders respond to audience pressures as they consider whether to fight or settle