1,345 research outputs found
X-ray testing ATHENA optics at PANTER
No full textSilicon pore optic (SPO) mirror modules (MMs) are being developed and produced for ESA’s ATHENA mission. The optics have, and will be, tested at MPEs PANTER x-ray test facility. We present the results obtained from tests performed at the PANTER x-ray test facility for the SPO MM-0050 that was produced to verify the latest optical performance (half energy width (HEW), effective area) of SPOs, supporting the ESA reviews of their optical performance.The preparations are ongoing at PANTER, ESA, cosine and Media Lario to perform complex opto-thermo-mechanical tests of the two full scale 1/6th sectors of the final ATHENA mirror assembly structure produced by the potential ATHENA primes Airbus Defence and Space and Thales Alenia Space. For these tests a set of three SPO MMs have been produced following the flight configuration. The MMs will be incorporated into the full scale 1/6th sectors to measure the impact of thermal gradients on the thermoelastic deformation of the structure and therefore the HEW performance. A description of the tests is presented here.PANTER is also involved in the development, testing, and fabrication of the mirror adapter structure (MAS) to support the 2.6-m diameter ATHENA mirror assembly module demonstrators (MAMD) during the planned x-ray tests at XRCF. A description of the PANTER tests and results will be presented in this paper together with a short overview of the MAS MGSE for XRCF
Developments in testing x-ray optics at MPE's PANTER facility
No full textThe PANTER X-ray test facility of the Max Planck Institute for Extraterrestrial Physics (MPE) has over 40 years of heritage in testing and calibrating x-ray optics. Having contributed to missions such as XMM-Newton, Chandra, and eROSITA, the facility measures the performance of x-ray optic technologies that will enable future x-ray telescopes to be realised. Over the last year, PANTER has been testing the latest developments in silicon pore optics for ESA’s ATHENA mission, as well as full-shell eROSITA-like optics for the CAS/ESA/MPE Einstein Probe mission. For ATHENA, complete mirror modules for the outer radius of the telescope have been tested. The latest developments in the optics for the mid-radius of the telescope, including the first confocal mirror module, have been measured for performance. The paper will provide an overview of the most recent testing carried out at PANTER, and the alignment and measurement techniques used
X-ray testing at PANTER of optics for the ATHENA and Arcus Missions
No full textCurrently for the European Space Agency (ESA) ATHENA [1,2] mission Silicon Pore Optic (SPO) [3-8] Mirror Modules (MM) with a focal length of f = 12 m, are being developed and tested. The SPO MMs are also the baseline optic for the NASA medium explorer high-resolution spectroscopy mission Arcus [9-10] with f = 12 m that is currently undergoing a phase A study. SPOs are currently being tested at both the PTB laboratory of the BESSY synchrotron facility in Berlin using an X-ray pencil beam and the PANTER X-ray test facility in Neuried of the Max-Planck-Institut für extraterrestrische Physik, Garching using a long vacuum beamline (distance source to optic ~120 m). The different types of measurements performed at PANTER to characterise the ATHENA and Arcus optics will be discussed. This will be done on the level of an X-ray optical unit (XOU) composed of both a primary and secondary High Performance Optic (HPO) stack, a mirror module (MM) composed of two XOUs, small (<4 MMs) and large (< 25 MM) petals, and the complete integrated optic Athena (700-1000 MMs) and Arcus (4 petals each with 38 MMs). The main set of tests that are currently done at PANTER make full use the possibility to fully-illuminate single XOUs, MMs, and petals to determine their optical characteristics such as the half energy width of the point spread function as well as the effective area and the vignetting function at different energies. To ensure that the measurements, that are required to demonstrate the performance of ATHENA, are possible, a description of recent and upcoming upgrades to the PANTER X-ray test facility will be given. Finally, a status update on the progress on designing the new facility to be used to test and calibrate the complete ATHENA mirror will be presented
X-ray ray tracing with Zemax for the PANTER testing facility
No full textThe PANTER X-ray test facility of the Max Planck Institute for Extraterrestrial Physics (MPE) has been testing and calibrating optics from various space missions world-wide for more than 40 years. Recently, PANTER measured the performance of the latest x-ray optic technologies of SVOM, Einstein Probe and Athena. Towards accelerating calibrations, we aim to predict the behavior of optics when introduced into vacuum. The optics are modeled with computer aided design (CAD) and ray-traced with Zemax' non-sequential mode. This allows tracing the point spread function (PSF) on the detector plane from complex X-ray optics, including Wolter-type optics, Parabolic mirror, Hybrid KirkPatrick Baez and Lobster Eye optics. We compare PANTER experiments to equivalent simulation setups, including a focal scan. We find good agreement between simulations and experiments in terms of PSF, and location of the focal plane. Zemax ray tracing appears to be a powerful and flexible tool to understand and predict calibration experiments at PANTER
X-ray testing at PANTER of optics for the ATHENA and Arcus Missions
No full textCurrently for the European Space Agency (ESA) ATHENA [1,2] mission Silicon Pore Optic (SPO) [3-8] Mirror Modules (MM) with a focal length of f = 12 m, are being developed and tested. The SPO MMs are also the baseline optic for the NASA medium explorer high-resolution spectroscopy mission Arcus [9-10] with f = 12 m that is currently undergoing a phase A study. SPOs are currently being tested at both the PTB laboratory of the BESSY synchrotron facility in Berlin using an X-ray pencil beam and the PANTER X-ray test facility in Neuried of the Max-Planck-Institut für extraterrestrische Physik, Garching using a long vacuum beamline (distance source to optic ~120 m). The different types of measurements performed at PANTER to characterise the ATHENA and Arcus optics will be discussed. This will be done on the level of an X-ray optical unit (XOU) composed of both a primary and secondary High Performance Optic (HPO) stack, a mirror module (MM) composed of two XOUs, small (<4 MMs) and large (< 25 MM) petals, and the complete integrated optic Athena (700-1000 MMs) and Arcus (4 petals each with 38 MMs). The main set of tests that are currently done at PANTER make full use the possibility to fully-illuminate single XOUs, MMs, and petals to determine their optical characteristics such as the half energy width of the point spread function as well as the effective area and the vignetting function at different energies. To ensure that the measurements, that are required to demonstrate the performance of ATHENA, are possible, a description of recent and upcoming upgrades to the PANTER X-ray test facility will be given. Finally, a status update on the progress on designing the new facility to be used to test and calibrate the complete ATHENA mirror will be presented
Calibration of X-ray telescope prototypes at PANTER
No full textWe report on a ground X-ray calibration of two X-ray telescope prototypes at the PANTER X-ray Test Facility, operated by the Max-Planck-Institute for Extraterrestrial Physics, in Neuried, Germany. The X-ray telescope prototypes were developed by the Institute of Precision Optical Engineering (IPOE) of Tongji University, in a conical Wolter-I configuration, using thermal glass slumping technology. Prototype #1 with three layers and Prototype #2 with 21 layers were tested to assess the prototypes' on-axis imaging performance. The measurement of Prototype #1 indicates a Half Power Diameter (HPD) of 82'' at 1.49 keV. As for Prototype #2, we performed more comprehensive measurements of on-axis angular resolution and effective area at several energies ranging from 0.5–10 keV. The HPD and effective area are 111'' and 39 cm2 at 1.49 keV, respectively, at which energy the on-axis performance of the prototypes is our greatest concern
Influence of oxide films on primary water stress corrosion cracking initiation of alloy 600
No full textIn the present study alloy 600 was tested in simulated pressurised water reactor (PWR) primary water, at 360 °C, under an hydrogen partial pressure of 30 kPa. These testing conditions correspond to the maximum sensitivity of alloy 600 to crack initiation. The resulting oxidised structures (corrosion scale and underlying metal) were characterised. A chromium rich oxide layer was revealed, the underlying metal being chromium depleted. In addition, analysis of the chemical composition of the metal close to the oxide scale had allowed to detect oxygen under the oxide scale and particularly in a triple grain boundary. Implication of such a finding on the crack initiation of alloy 600 is discussed. Significant diminution of the crack initiation time was observed for sample oxidised before stress corrosion tests. In view of these results, a mechanism for stress corrosion crack initiation of alloy 600 in PWR primary water was proposed
40Ar–39Ar dating of volcanogenic products from the AND-2A core (ANDRILL Southern McMurdo Sound Project, Antarctica): correlations with the Erebus Volcanic Province and implications for the age model of the core
No full textThe AND-2A drillcore (Antarctic Drilling Program-ANDRILL) was successfully completed in late 2007 on the Antarctic continental margin (Southern McMurdo Sound, Ross Sea) with the aim of tracking ice proximal to shallow marine environmental fluctuations and to document the 20-Ma evolution of the Erebus Volcanic Province. Lava clasts and tephra layers from the AND-2A drillcore were investigated from a petrographic and stratigraphic point of view and analyzed by the Ar-40-Ar-39 laser technique in order to constrain the age model of the core and to gain information on the style and nature of sediment deposition in the Victoria Land Basin since Early Miocene. Ten out of 17 samples yielded statistically robust Ar-40-Ar-39 ages, indicating that the AND-2A drillcore recovered a parts per thousand currency sign230 m of Middle Miocene (similar to 128-358 m below sea floor, similar to 11.5-16.0 Ma) and > 780 m of Early Miocene (similar to 358-1093 m below sea floor, similar to 16.0-20.1 Ma). Results also highlight a nearly continuous stratigraphic record from at least 358 m below sea floor down hole, characterized by a mean sedimentation rate of similar to 19 cm/ka, possible oscillations of no more than a few hundreds of ka and a break within similar to 17.5-18.1 Ma. Comparison with available data from volcanic deposits on land, suggests that volcanic rocks within the AND-2A core were supplied from the south, possibly with source areas closer to the drill site for the upper core levels, and from 358 m below sea floor down hole, with the "proto-Mount Morning" as the main source
Effects of drought and vegetation management on the establishment of 3 tree species in Northamptonshire, England
No full textWater is a limiting factor in the distribution and growth of trees. Changing climatic
conditions are likely to significantly effect tree species development. The planting and
establishment of trees needs to take into account these changing factors in terms of
design and species selection. This study looked at survival and growth of newly planted
trees under field scale conditions and the effects of soil water availability and ground
treatments. The experiment followed a blocked plan allowing a line source design to
irrigate three tree species, ash, Douglas fir and oak. Each plot of 90 trees was divided
into 5 irrigation subplots with varying levels of water application. Two ground
treatments, bare ground and vegetated were also applied. Over a three year period,
there was a significant effect of species (P<0.001) and herbicide application (P<0.01)
on tree survival. Tree height and diameter were significant (P<0.01) between species
and herbicide. Irrigation had a significant effect on growth rates of all species with no
effect on survival. Ground vegetation biomass significantly increased in high irrigation
subplots (P<0.01), with increasing festuca rubra dominance decreasing plant diversity
(R2=0.8533). The results suggest that soil moisture availability increases tree growth
but does not significantly improve survival rates of the tree species studied. Water is a
key factor in the establishment of trees with maintained soil moisture increasing growth
development of individuals. Therefore site and species selection are essential in the
design of woodland plantings for conservation, recreation and commercial activities
The Fossil Record of Star Formation from Galaxy Spectra
No full textIn this thesis I present work using the MOPED algorithm to extract in a non-parametric fashion
star formation histories and galaxy masses from the spectra of galaxies in the Sloan Digital Sky
Survey. The recovered parameters for all galaxies are combined to give insight into the processes
of star and galaxy formation on both individual galaxy and cosmic scales.
The MOPED algorithm allows use of the entire spectral range, rather than concentrating on
specific features, and can be used to estimate the complete star formation history without prior
assumptions about its form. By combining the star formation histories of 96,545 galaxies in the
redshift range 0 < z < 0:34 the cosmic star formation rate is determined from the present day
to z ~ 6. The results show that the peak of star formation occurred at z ~ 0:6, and that 26% of
the mass of stars in the present-day Universe was formed at z ~ 2. The average metallicity rises
from Z/Z= 0:44 at high redshift to a peak of 0:8 at z ~ 1 before declining to a level around 0.25 atthe present day. Although the peak in star formation is more recent than previously thought, the sample used includes galaxies with a range of masses not accessible to traditional studies, down
to a limit of L ~ 2 x 10-3L*.
By cutting the sample into ranges of mass it can be seen that the redshift at which starformation
activity peaks is an essentially monotonically increasing function of final stellar mass.
The time of the peak in star formation ranges from z > 2 for the highest mass galaxies (MS <
1012M) to z ~ 0:2 for the lowest (MS < 1010M). A typical L* galaxy appears to have its peak
at around z » 0:8. These differences in star formation with mass reconcile the redshift of the
peak found in this work with the previous estimates, generally deep surveys only probe the SFR of galaxies with MS < ML*.
The stellar mass calculated using the reconstructed spectra eliminates contamination from either
emission lines or AGN components. Using these masses it is possible to construct the mass
function for the stellar mass component of galaxies which give excellent agreement with previous
works, but extend their range by more than two decades in mass to 10 7.5 < Ms/h-2M < 1012.
I present both a standard Schechter fit and a fit modified to include an extra, high-mass contribution,
possibly from cluster cD galaxies. The Schechter fit parameters are phi* = (7:8 +/- 0:1) £
10-3h3Mpc-3, M* = (7.64 +/- 0.09) x 10*10h-2M and alpha = -1.159 +/- 0.008. The sample also
yields an estimate for the contribution from baryons in stars to the critical density of omega b*h =
(2.39+/-0.08)x10-3, in good agreement with other indicators. No evolution of the mass function
in the redshift range 0:05 < z < 0:34 is apparent, indicating that almost all stars were already
formed at z » 0:34 with little or no star formation activity since then and that the evolution seen
in the luminosity function must be largely due to stellar fading.
The star formation history can be interpreted as a measure of how gas was transformed into
stars as a function of time and stellar mass: the Baryonic Conversion Tree (BCT). There is a clear correlation between early star formation activity and present-day stellar mass: the more massive
galaxies have formed about 80% of their stars at z > 1, while for the less massive ones the
value is only about 20%. Comparing the BCT to the dark matter merger tree indicates that star
formation efficiency at z > 1 had to be high (as much as 10%) in galaxies with present-day stellar
mass larger than 2 x 10*11M, if this early star formation occurred in the main progenitor. The
LCDM paradigm can accommodate a large number of red objects; it is the high efficiency in the
conversion from gas to stars that needs to be explained. On the other hand, in galaxies with
present-day stellar mass less than 10*11M, efficient star formation seems to have been triggered
at z ~ 0:2. This work shows that there is a characteristic mass (M » 10*10M) for feedback
efficiency (or lack of star formation). For galaxies with masses lower than this, feedback (or star
formation suppression) is very efficient while for higher masses it is not. The BCT, determined
here for the first time, should be an important observable with which to confront theoretical
models of galaxy formation
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