The Euclid Imaging Channels Instrument of the Euclid mission is designed to study the weak gravitational lensing
cosmological probe. The combined Visible and Near Infrared imaging channels will be controlled by a common data
handling unit (PDHU), implementing onboard the instrument digital interfaces to the satellite. The PDHU main
functionalities include the scientific data acquisition and compression, the instrument commanding and control and the
instrument health monitoring. Given the high data rate and the compression needs, an innovative architecture, based on
the use of several computing and interface modules, considered as building blocks of a modular design will be presented.
The Euclid Near-Infrared Spectrometer (E-NIS) Instrument was conceived as the spectroscopic probe on-board the ESA
Dark Energy Mission Euclid. Together with the Euclid Imaging Channel (EIC) in its Visible (VIS) and Near Infrared
(NIP) declinations, NIS formed part of the Euclid Mission Concept derived in assessment phase and submitted to the
Cosmic Vision Down-selection process from which emerged selected and with extremely high ranking. The Definition
phase, started a few months ago, is currently examining a substantial re-arrangement of the payload configuration due to
technical and programmatic aspects. This paper presents the general lines of the assessment phase payload concept on
which the positive down-selection judgments have been based.
The benefits Astronomy could gain by performing multi-slit spectroscopy in a space mission is renown. Digital
Micromirror Devices (DMD), developed for consumer applications, represent a potentially powerful solution. They are
currently studied in the context of the EUCLID project. EUCLID is a mission dedicated to the study of Dark Energy
developed under the ESA Cosmic Vision programme. EUCLID is designed with 3 instruments on-board: a Visual
Imager, an Infrared Imager and an Infrared Multi-Object Spectrograph (ENIS). ENIS is focused on the study of Baryonic
Acoustic Oscillations as the main probe, based on low-resolution spectroscopic observations of a very large number of
high-z galaxies, covering a large fraction of the whole sky. To cope with these challenging requirements, a highmultiplexing
spectrograph, coupled with a relatively small telescope (1.2m diameter) has been designed. Although the
current baseline is to perform slit-less spectroscopy, an important option to increase multiplexing rates is to use DMDs as
electronic reconfigurable slit masks. A Texas Instrument 2048x1080 Cinema DMD has been selected, and space
validation studies started, as a joint ESA-ENIS Consortium effort. Around DMD, a number of suited optical systems has
been developed to project sky sources onto the DMD surface and then, to disperse light onto IR arrays. A detailed study
started, both at system and subsystem level, to validate the initial proposal. Here, main results are shown, making clear
that the use of DMD devices has great potential in Astronomical Instrumentation.
The ESA Planck mission is the third generation (after COBE and WMAP) space experiment dedicated to the measurement
of the Cosmic Microwave Background (CMB) anisotropies. Planck will map the whole CMB sky using two instruments in
the focal plane of a 1.5 m off-axis aplanatic telescope. The High Frequency Instrument (HFI) is an array of 52 bolometers
in the frequency range 100-857 GHz, while the Low Frequency Instrument (LFI) is an array of 11 pseudo-correlation
radiometric receivers which continuously compare the sky signal with the reference signal of a blackbody at ~ 4.5 K.
The LFI has been tested and calibrated at different levels of integration, i.e. on the single units (feed-horns, OMTs, amplifiers,
waveguides, etc.), on each integrated Radiometric Chain Assembly (RCA) and finally on the complete instrument,
the Radiometric Array Assembly (RAA). In this paper we focus on some of the data analysis algorithms and methods that
have been implemented to estimate the instrument performance and calibration parameters.
The paper concludes with the discussion of a custom-designed software package (LIFE) that allows to access the
complex data structure produced by the instrument and to estimate the instrument performance and calibration parameters
via a fully graphical interface.
In this paper we present the test results of the qualification model (QM) of the LFI instrument, which is being
developed as part of the ESA Planck satellite. In particular we discuss the calibration plan which has defined
the main requirements of the radiometric tests and of the experimental setups. Then we describe how these
requirements have been implemented in the custom-developed cryo-facilities and present the main results. We
conclude with a discussion of the lessons learned for the testing of the LFI Flight Model (FM).
Planck is the third Medium-Sized Mission (M3) of ESA Horizon 2000 Scientific Programme. It is designed to image the anisotropies of the Cosmic Background Radiation Field over the whole sky, with unprecedented sensitivity and angular resolution.
Planck carries two main experiments named HFI (High Frequency Instrument) and LFI (Low Frequency Instrument). The first is based on bolometers, the latter is an array of tuned radio receivers, based on High Electron Mobility Transistors (HEMTs) amplifier technology, and covering the frequency range from 30 to 70 GHz. The Front-End Electronics Modules (FEM’s) are cooled at 20K by a H2 sorption cooler. The high frequency signals (up to 70 GHz) are amplified, phase lagged and transported by means of waveguides to the warm back-end electronics at temperatures of the order of 300K.
The 20 K cooling is achieved exploiting a two-stage cooling concept. The satellite is passively cooled to temperatures of the order of 60K using special designed radiators called V-grooves. An H2 sorption cooler constitutes the second active cooling stage, which allows focal plane temperatures of 20K, i.e. compatible with the tight noise requirements of the Low Noise Amplifiers (LNA’s).
Each FEM needs 22 bias lines characterised by a high immunity to external noise and disturbances. The power required for each FEM ranges from 16 to 34mW, depending on the radiometer frequency. Due to the limited cooling power of the sorption cooler (about 2W), the heat transport through the harness and therefore the parasitics on the focal plane, shall be minimised. A total of 290 wires have to be routed from the warm electronics (300K) to the cold focal plane (20K), along a path of about 2200mm, transporting currents ranging from a few uA up to 240mA.
The present paper analyses the thermal and electrical problems connected with the design of a suitable cryo-harness for the bias of the radiometers cryogenic front-end modules of LFI. Two possible approaches are proposed, and a solution presented.
Silicon Drift Detectors (SDDs) with integrated readout transistors combine a large sensitive area with a small total readnode capacitance and are therefore well suited for high resolution, high count rate X-ray spectroscopy. The low leakage current level obtained by elaborated process technology makes it possible to operate them at room temperature or with moderate thermo-electric cooling. The monolithic combination of several SDDs to a multichannel drift detector solves the limited of size and allows for the realization of new physics experiments and systems. Up to 3 cm2 large SDDs for spectroscopic applications were fabricated and tested. Position sensitive X-ray systems are introduced. The description of the device principle is followed by the introduction of the multichannel drift detector concept. Layout, performance and examples of current and future applications are presented.
Silicon Drift Detectors (SDDs) with integrated readout transistor combine a large sensitive area with a small value of the output capacitance and are therefore well suited for high resolution, high count rate X-ray spectroscopy. The low leakage current level obtained by the elaborated process technology makes it possible to operate them at room temperature or with moderate cooling. The monolithic combination of a number of SDDs to a Multichannel Drift Detector solves the limitation in size of the single device and allows the realization of new physics experiments and systems. The description of the device principle is followed by the introduction of the Multichannel Drift Detector concept. Layout, performance, and examples of current and future applications are given.
The main features of silicon drift detector modules currently produced by KETEK GmbH and MPI Halbleiterlabor, Munich will be summarized, giving an overview over state of the art and future possible applications.
Silicon Drift Detectors (SDDs) have been recently employed as scintillation detectors for (gamma) -ray spectroscopy and imaging applications. With respect to conventional PMTs, these devices offer the higher quantum efficiency to the scintillation light, typical of a silicon detector. Moreover, thanks to the low value of output capacitance, a SDD is characterized by a lower electronics noise with respect to a conventional silicon photodiode. This feature allows a detector based on the CsI(Tl)-SDD architecture to reach high energy and position resolution in gamma detection. In this work we present the results obtained in the development of a first prototype of gamma detector for 1D position measurements and of a first prototype of small gamma camera for 2D position measurements, both detectors based on a single scintillator coupled to an array of SDDs.