The Adaptive Gain Integrating Pixel Detector at the European XFEL

The Adaptive Gain Integrating Pixel Detector (AGIPD) is an x-ray imager, custom designed for the European x-ray Free-Electron Laser (XFEL). It is a fast, low noise integrating detector, with an adaptive gain amplifier per pixel. This has an equivalent noise of less than 1 keV when detecting single photons and, when switched into another gain state, a dynamic range of more than 10$^4$ photons of 12 keV. In burst mode the system is able to store 352 images while running at up to 6.5 MHz, which is compatible with the 4.5 MHz frame rate at the European XFEL. The AGIPD system was installed and commissioned in August 2017, and successfully used for the first experiments at the Single Particles, Clusters and Biomolecules (SPB) experimental station at the European XFEL since September 2017. This paper describes the principal components and performance parameters of the system.Comment: revised version after peer revie

Depth Profile of Signal Charge Collected in Heavily Irradiated Silicon Pixels

The response of heavily irradiated Silicon n-pixels to minimum ionizing particles has been measured using pions traversing rows of pixels at a grazing angle of 8 degrees. With this method the charge collection efficiency can be determined as a function of detector depth. The results indicate that charge trapping effects can be kept at an acceptable level by running the detectors at bias voltages of a few hundred Volts. For pixels irradiated with 6.1 E14 pions/cm2 we find signals of 9700 e- for a bias of 300 Volts

An instrument to measure students'perception of the authenticity of an out-of-school learning Place

Progress in Science Education, Vol. 4, No. 1, S. 66-74,Background: One of the big opportunities offered by out-of-school learning places at research institutions is their authenticity, as they can provide insight into authentic research and work of scientists. Purpose: To what extent the students perceive this “authenticity of place” may however be individually different. In order to measure whether students indeed perceive a given out-of-school learning offer as an authentic learning place from their individual perspective an instrument is needed. Sample/setting: The Paul Scherrer Institute (PSI) is a genuine research environment for natural and engineering sciences and can therefore be considered as an authentic out-of-school learning place. Students from 3 different cantons in Switzerland participated in a field trip to the PSI, including a guided tour to one of its research facilities (on renewable energies) and a hands-on workshop in its science outreach lab (iLab) related to that topic. Data about test characteristics were collected in a pilot and in a main study (n = 80, March 2018 and n = 94, May to September 2018). All the classes were taught by the same teacher to learn about the basics of the research being done in that particular field of research at PSI. The guided tour was done by the same scientist from PSI for all classes. Design and methods: The questionnaire consists of a 6 point Likert scale with 9 items. An item analysis was carried out, as well as a factor analysis testing for the dimensionality of the questionnaire. Results: In terms of content the items for authenticity of place can be divided into one group with a cognitive focus and another group with an emotional focus. The item analysis of the total instrument yields good to very good characteristics (Cronbach’s Alpha as estimate of internal consistency ?C = .91, average item-test-correlation rit = .71), similarly for the sub-tests with cognitive and emotional focus (?C = .80, rit = .63 and ?C = .89, rit = .77) A performed confirmatory factor analysis proved compatible with a two-factor and a one-factor model (CFI = 0.98 and 0.97, respectively). The fact that the correlation between the two factors “cognitive” and “emotional” is very high (.94) argues in favour of the one factor model (McDonald’s omega as estimate of internal consistency adapted to factor analysis: ? = 0.92). Conclusions/Implications for practice and future research: The instrument presented here can be used as a one factor scale with good to very good test characteristics, if an overall measure of perceived authenticity of place is needed. The two subscales with cognitive and emotional focus could also be used separately, as their test characteristics are also satisfactory to good. Due to its short format and administration time (around 2 minutes) the instrument can be well integrated in the evaluation of out-of-school learning places. The scale was developed specifically for a research institute and has to be adapted for other out-of-school learning places such as museums, science centres or field trips. For future research it will be interesting to include other dimensions of perceived authenticity (such as authenticity of a person, e.g. the scientist at a research institute) and to study their combined effects on educational outcomes. Work along these lines within the framework of a larger research project on out-of-school science learning is in progress

Linear and non-linear response of late Neogene glacial cycles to obliquity forcing and implications for the Milankovitch theory

Constraints are given for the geometry and time lags of the prominent obliquity-paced glacial stages 100, 98 and 96, which mark a major phase in Northern Hemisphere (NH) glaciations during the late Pliocene (2.56–2.4 Ma ago). For this purpose a high-resolution benthic δ18O record was constructed from the astronomically tuned Mediterranean ODP Site 967 and decomposed into an ice volume and an annual NH (40–80° N) temperature component using an inverse modelling approach. Our results indicate that the dominant 41 ky component in δ18O lags obliquity by 6.5 ± 0.6 ky, which approximates late Pleistocene estimates. Maximum (minimum) ice volume growth occurred in phase with obliquity minima (maxima), which invoked low (high) total summer energy conditions that reduced (increased) ice-sheet ablation. Sea level dropped 60–70 m during full glacial conditions. Similar to late Pleistocene ice core and marine δ18O records, our late Pliocene δ18O record reveals significant power at ∼28 ky, which appear to be bound to the major glacial terminations. We argue that this beat most likely reflects the sum frequency of the 41 ky prime and its multiples of 82 and 123 ky, supporting the theory that the late Neogene glacial cycles are primarily determined by the linear and non-linear response mechanisms of the ice sheets to the obliquity forcing. Evidence for such a scenario may come from the alignment between the Devils Hole δ18O chronology and the sum of the filtered linear and non-linear obliquity-related components of late Pleistocene climate records, suggesting that the ∼28 ky beat is intrinsic to the climate system or at least an important constituent of the annual high-latitude NH temperature changes that have set the stage for the geometry of the glacial–interglacial variability throughout the course of the Pliocene and Pleistocene

Regards croisés sur Bernd Alois Zimmermann

Ces Regards croisés sur Bernd Alois Zimmermann offrent pour la première fois en français une série d'études sur la musique de ce musicien majeur de l'après-guerre. Ils ont pour origine le colloque qui s'est tenu à Strasbourg en 2010 dans le cadre du Festival Musica, à l'instigation de l'Université de Strasbourg. La première partie de ces Regards croisés fait appel aux interprètes : Hans Zender, qui fut un proche du compositeur, souligne son actualité, le chef d'orchestre Peter Hirsch et le violoncelliste Pierre Strauch se penchent sur certaines œuvres. Dans une deuxième section, Oliver Korte, Pascal Decroupet, Heribert Henrich et Werner Strinz traitent des questions de langage musical. Dans une troisième section, le théologien Beat Föllmi dévoile le sens profond de l'Action ecclésiastique, œuvre ultime du compositeur, tandis que Dörte Schmidt et Ulrich Mosch abordent la question du ballet, si importante pour lui. Dans une dernière section, Jörn Peter Hiekel reconsidère la place de Zimmermann aujourd'hui, tandis que Ralph Paland étudie les œuvres électroacoustiques du compositeur. Enfin, Laurent Feneyrou explore les fondements philosophiques de sa réflexion sur le temps. Un entretien inédit avec la veuve du compositeur clôt cet ouvrage, qui se présente comme le complément des Écrits de Zimmermann publiés l'an dernier par les Éditions Contrechamps.à la mémoire de Laurence Helle

Regards croisés sur Bernd Alois Zimmermann

Ces Regards croisés sur Bernd Alois Zimmermann offrent pour la première fois en français une série d'études sur la musique de ce musicien majeur de l'après-guerre. Ils ont pour origine le colloque qui s'est tenu à Strasbourg en 2010 dans le cadre du Festival Musica, à l'instigation de l'Université de Strasbourg. La première partie de ces Regards croisés fait appel aux interprètes : Hans Zender, qui fut un proche du compositeur, souligne son actualité, le chef d'orchestre Peter Hirsch et le violoncelliste Pierre Strauch se penchent sur certaines œuvres. Dans une deuxième section, Oliver Korte, Pascal Decroupet, Heribert Henrich et Werner Strinz traitent des questions de langage musical. Dans une troisième section, le théologien Beat Föllmi dévoile le sens profond de l'Action ecclésiastique, œuvre ultime du compositeur, tandis que Dörte Schmidt et Ulrich Mosch abordent la question du ballet, si importante pour lui. Dans une dernière section, Jörn Peter Hiekel reconsidère la place de Zimmermann aujourd'hui, tandis que Ralph Paland étudie les œuvres électroacoustiques du compositeur. Enfin, Laurent Feneyrou explore les fondements philosophiques de sa réflexion sur le temps. Un entretien inédit avec la veuve du compositeur clôt cet ouvrage, qui se présente comme le complément des Écrits de Zimmermann publiés l'an dernier par les Éditions Contrechamps.à la mémoire de Laurence Helle