Search results for "bolometer"
showing 4 items of 24 documents
X-ray spectroscopy of MXB 1728-34 with XMM-Newton
2011
We have analysed an XMM-Newton observation of the low mass X-ray binary and atoll source MXB 1728-34. The source was in a low luminosity state during the XMM-Newton observation, corresponding to a bolometric X-ray luminosity of 5*10E36 d^2 erg/s, where d is the distance in units of 5.1 kpc. The 1-11 keV X-ray spectrum of the source, obtained combining data from all the five instruments on-board XMM-Newton, is well fitted by a Comptonized continuum. Evident residuals are present at 6-7 keV which are ascribed to the presence of a broad iron emission line. This feature can be equally well fitted by a relativistically smeared line or by a self-consistent, relativistically smeared, reflection mo…
Thermal characteristics of silicon nitride membranes at sub-Kelvin temperatures
1998
We have performed calorimetric measurements on 200 nm thin silicon nitride membranes at temperatures from 0.07 to 1 K. Besides full windows, membranes cut into a thermally isolating suspended bridge geometry were investigated. Based on dc and ac measurements employing normal-metal/insulator/superconductor (NIS) tunnel junctions both as a thermometer and a heater, we report on heat transport and thermal relaxation in silicon nitride films. The bridge structure improves thermal isolation and, consequently, energy sensitivity by two orders of magnitude over those of the full membrane with the same size, and makes such a structure very attractive for bolometric and microrefrigeration applicatio…
The cryogenic anticoincidence detector for ATHENA-XMS: preliminary results from the new prototype
2012
ATHENA has been the re-scoped IXO mission, and one of the foreseen focal plane instrument was the X-ray Microcalorimeter Spectrometer (XMS) working in the energy range 0.3-10 keV, which was a kilo-pixel array based on TES (Transition Edge Sensor) detectors. The need of an anticoincidence (AC) detector is legitimated by the results performed with GEANT4 simulations about the impact of the non x-ray background onto XMS at L2 orbit (REQ. < 0.02 cts/cm2/s/keV). Our consortium has both developed and tested several samples, with increasing area, in order to match the large area of the XMS (64 mm2). Here we show the preliminary results from the last prototype. The results achieved in this work off…
Improved EDGE2D-EIRENE simulations of JET ITER-like wall L-mode discharges utilising poloidal VUV/visible spectral emission profiles
2015
A discrepancy in the divertor radiated powers between EDGE2D-EIRENE simulations, both with and without drifts, and JET-ILW experiments employing a set of NBI-heated L-mode discharges with step-wise density variation is investigated. Results from a VUV/visible poloidally scanning spectrometer are used together with bolometric measurements to determine the radiated power and its composition. The analysis shows the importance of D line radiation in contributing to the divertor radiated power, while contributions from D radiative recombination are smaller than expected. Simulations with W divertor plates underestimate the Be content in the divertor, since no allowance is made for Be previously …