Multistage Zeeman deceleration of atomic and molecular oxygen

Multistage Zeeman deceleration is a technique used to reduce the velocity of neutral molecules with a magnetic dipole moment. Here we present a Zeeman decelerator that consists of 100 solenoids and 100 magnetic hexapoles, that is based on a short prototype design presented recently [Phys. Rev. A 95, 043415 (2017)]. The decelerator features a modular design with excellent thermal and vacuum properties, and is robustly operated at a 10 Hz repetition rate. This multistage Zeeman decelerator is particularly optimized to produce molecular beams for applications in crossed beam molecular scattering experiments. We characterize the decelerator using beams of atomic and molecular oxygen. For atomic oxygen, the magnetic fields produced by the solenoids are used to tune the final longitudinal velocity in the 500 - 125 m/s range, while for molecular oxygen the velocity is tunable in the 350 - 150 m/s range. This corresponds to a maximum kinetic energy reduction of 95% and 80% for atomic and molecular oxygen, respectively.Comment: Latest version as accepted by Physical Review

An integrated approach to inquiry based science learning in a secondary school: designing a colony on Mars

Presentation at INTED.The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement N° 318499 - weSPOT project

'Der zotten ende der narrenscip' in het kielzog van 'Dasz Narrenschyff' en 'Stultifera Nauis'

Sebastian Brants Narrenschyff (1494) werd door Jakob Locher (1497a) in het Latijn bewerkt onder de titel Stultifera Nauis. Lochers tweede editie (1497b) inspireerde Josse Bade tot het schrijven van de Nederlandse tegenhanger Dit is der zotten ende der narren scip (1500). Bades narrenschip verschilt in zovele opzichten van zowel Brants als Lochers werk dat het niet moet worden beschouwd als een bewerking, maar wel als een drastische omwerking van zijn Duitse en Latijnse voorbeeld. Sebastian Brant’s Narrenschyff (1494) was adapted in Latin under the title Stultifera Nauis by Jakob Locher (1497a). Its second edition (Locher 1497b) inspired Josse Bade to compose the Dutch pendant Dit is der zotten ende der narren scip (1500). It differs from both Brant’s and Locher’s book in so many respects that it is not an adaptation of their work: it should be valued as a rewrite

Josse Bade: auteur van 'dit is der zotten ende der narren scip (1500)

The book Dit is der zotten ende der narren scip was printed in 1500 in Paris by Guide Coopman as the colophon says. Who the author is, is revealed by neither the colophon, nor the title page. It will be argued that it is Josse Bade, the famous humanist, who wrote the book. The book’s language corresponds to Bade’s Flemish in Jouennaux & Bade (1508). The content is consonant with Bade’s literary and annotative Latin products

Teachers’ professional development: An analysis of the use of Professional Development Plans in a Dutch school

Professional development of teachers has become an essential condition in today’s knowledge-based society to sustain the quality of teaching. Therefore, the Dutch government promotes this now professional development. As a result, Professional Development Plans (PDPs) are now increasingly used to stimulate and support the professional development of teachers. A PDP is used to encourage teachers’ professional development and structure their development path in terms of learning goals and plans of action. However, it cannot be taken for granted that teachers will formulate high-quality PDPs on their own. Previous research suggests that guidance is important in supporting teachers’ development. This study examined the effects of guidance on the quality of PDPs. An experimental group of Dutch teachers from a school for secondary vocational education was offered a series of workshops whereas the control group did not have such guidance. Both groups had to fill out a simple structured PDP. To determine the quality of the PDPs, an assessment tool was developed. The results suggest that guided teachers are more capable of identifying their strengths and in formulating learning goals. The guided teachers’ PDPs also showed more consistency. No differences were found regarding the action plans which teachers described

Teachers’ beliefs about using a professional development plan

Professional development plans (PDPs) have recently been introduced in Dutch schools to support teachers’ professional development. However, teachers’ beliefs regarding the use of PDPs have not been systematically researched, whereas research on the use of PDPs indicates that the implementation is not always successful and depends on how use is perceived by users. Some teachers may doubt the usefulness and purpose of a PDP, and this might influence their reactions to its intro- duction. Using Fishbein and Ajzen’s theory of planned behav- iour, the current study explored teachers’ characteristics (such as age and years of experience in education) and their beliefs about intention to use a PDP. Clusters of teachers with similar characteristics and beliefs were identified to permit the design of interventions specific to each cluster. Semi-structured inter- views were conducted to reveal these beliefs and characteristics for a sample of 41 teachers working in schools where using a PDP was mandatory. The results showed that most teachers had a positive attitude towards using a PDP. However, because using a PDP was mandatory, they felt pressured to produce one. Moreover, it was not a priority. This was because of their high workload. The present study contributes to the literature by adding knowledge of teachers’ beliefs about the use of PDPs. This knowledge may help the PDP to become a more effective device in promoting teachers’ professional development

Design and construction of a multistage Zeeman decelerator for crossed molecular beams scattering experiments

Zeeman deceleration is a relatively new technique used to obtain full control over the velocity of paramagnetic atoms or molecules in a molecular beam. We present a detailed description of a multistage Zeeman decelerator that has recently become operational in our laboratory [Cremers \emph{et al.}, Phys. Rev. A 98, 033406 (2018)], and that is specifically optimized for crossed molecular beams scattering experiments. The decelerator consists of an alternating array of 100 solenoids and 100 permanent hexapoles to guide or decelerate beams of paramagnetic atoms or molecules. The Zeeman decelerator features a modular design that is mechanically easy to extend to arbitrary length, and allows for solenoid and hexapole elements that are convenient to replace. The solenoids and associated electronics are efficiently water cooled and allow the Zeeman decelerator to operate at repetition rates exceeding 10 Hz. We characterize the performance of the decelerator using various beams of metastable rare gas atoms. Imaging of the atoms that exit the Zeeman decelerator reveals the transverse focusing properties of the hexapole array in the Zeeman decelerator