Terahertz superconducting hot electron bolometer heterodyne array receivers for NASA's GUSTO balloon observatory

The electromagnetic spectrum between 1 and 6 Terahertz contains unique information to understand important astrophysical phenomena such as the lifecycle of the interstellar medium (ISM). The latter is the material floating in between stars. The ISM lifecycle is crucial in studying the process of planet, star and galaxy’s formation, and can be traced by the radiation of fine structure lines using heterodyne receivers, a type of spectrometers that combine a high sensitivity with a high spectral resolution, operated from stratospheric balloons or space. GUSTO, the first balloon mission within NASA’s explorer program, is a THz observatory expected to launch in 2023 and will map fine structure lines of nitrogen [NII], carbon [CII], and oxygen [OI] along the Milky Way. This PhD thesis describes the development of the three 8-pixel detector arrays and the multi-beam local oscil-lator (LO) at 4.7 THz for GUSTO. Two chapters address the optimization of the optical beams of the detectors to obtain both uniform and parallel beams within an array. One chapter introduces the array architecture and discusses the performance characterization of the three arrays, demonstrating the highest pixel count monolithic detector array at THz with state of the art performance. The thesis ends with the design of the 4.7 THz LO, which is used to operate the respective array. This PhD research results in not only the key technologies that will be flown on NASA’s GUSTO, but also a scalable solution for the next generation of heterodyne detector arrays

Study on the viability of a 4x2 HEB mixer array at super-THz based on a Fourier phase grating LO for space applications

Various astronomical telescopes including Herschel, ALMA, STO and SOFIA-GREAT have successfully exploited THz radiation in order to explore the cosmos from the birth of the Universe to the life cycle of individual stars. The THz region, however, still remains relatively poorly observed due to poor transmission of THz light through Earth’s atmosphere as a result of past technological constraints. One such example is the observation of neutral oxygen [OI] at 4.7 THz which is only now opening up as a possibility for astronomical study. In this thesis we report on technology development aimed at implementing an advanced 4.7 THz astronomical receiver array for a proposed future NASA balloon mission called GUSTO. Several aspects of the receiver are studied in detail: HEB characterization and selection; Impact of lens size on device sensitivity; LO multiplexing at 1.4 THz using a 4x2 Fourier phase grating as a stepping stone to a 4.7 THz Fourier grating, including a demonstration of a 2x2 pixel array receiver using the central four beams of the grating output beam pattern. Conclusions are presented on the findings that will have direct input to the GUSTO mission

East Asia Today

East Asia attracts growing interest in the West. Th e region is the world’s hotbed of economic growth, led by burgeoning China aided by more advanced Asian economies investing heavily in manufacturing and trading networks involving China. Western entrepreneurs clamor to join the China wave

Portugal e a defesa europeia

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A política comum de segurança e defesa e o Conselho Europeu de Dezembro de 2013

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Isolamento

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Technical Design Report - TDR CYGNO-04/INITIUM

The aim of this Technical Design Report is to illustrate the technological choices foreseen to be implemented in the construction of the CYGNO-04 demonstrator, motivate them against the experiment physics goals of CYGNO-30 and demonstrate the financial sustainability of the project. CYGNO-04 represents PHASE 1 of the long term CYGNO roadmap, towards the development of large high precision tracking gaseous Time Projection Chamber (TPC) for directional Dark Matter searches and solar neutrino spectroscopy. The CYGNO project1 peculiarities reside in the optical readout of the light produced during the amplification of the primary ionization electrons in a stack of triple Gas Electron Multipliers (GEMs), thanks to the nice scintillation properties of the chosen He:CF4 gas mixture. To this aim, CYGNO is exploiting the fast progress in commercial scientific Active Pixel Sensors (APS) development for highly performing sCMOS cameras, whose high granularity and sensitivity allow to significantly boost tracking, improve particle identification and lower the energy threshold. The X-Y track project obtained from the reconstruction of the sCMOS images is combined with a PMT measurement to obtain a full 3D track reconstruction. In addition, several synergic R&Ds based on the CYGNO experimental approach are under development in the CYGNO collaboration (see Sec 2) to further enhance the light yield by means of electro luminescence after the amplification stage, to improve the tracking performances by exploiting negative ion drift operation within the INITIUM ERC Consolidator Grant, and to boost the sensitivity to O(GeV) Dark Matter masses by employing hydrogen rich target towards the development of PHASE 2 (see Sec. 1.2). While still under optimization and subject to possible significant improvements, the CYGNO experimental approach performances and capabilities demonstrated so far with prototypes allow to foresee the development of an O(30) m3 experiment by 2026 for a cost of O(10) MEUROs. A CYGNO-30 experiment would be able to give a significant contribution to the search and study of Dark Matter with masses below 10 GeV/c2 for both SI and SD coupling. In case of a Dark Matter observation claim by other experiments, the information provided by a directional detector such as CYGNO would be fundamental to positively confirm the galactic origin of the allegedly detected Dark Matter signal. CYGNO-30 could furthermore provide the first directional measurement of solar neutrinos from the pp chain, possibly extending to lower energies the Borexino measurement2. In order to reach this goal, the CYGNO project is proceeding through a staged approach. The PHASE 0 50 L detector (LIME, recently installed underground LNGS) will validate the full performances of the optical readout via APS commercial cameras and PMTs and the Montecarlo simulation of the expected backgrounds. The full CYGNO-04 demonstrator will be realized with all the technological and material choices foreseen for CYGNO-30, to demonstrate the scalability of the experimental approach and the potentialities of the large PHASE 2 detector to reach the expected physics goals. The first PHASE 1 design anticipated a 1 m3 active volume detector with two back-to-back TPCs with a central cathode and 500 mm drift length. Each 1 m2 readout area would have been composed by 9 + 9 readout modules having the LIME PHASE 0 dimensions and layout. Time (end of INITIUM project by March 2025) and current space availability at underground LNGS (only Hall F) forced the rescaling of the PHASE 1 active volume and design to a 0.4 m3, hence CYGNO-04. CYGNO-04 will keep the back-to-back double TPC layout with 500 mm drift length each, but with an 800 x 500 mm2 readout area covered by a 2 + 2 modules based on LIME design. The reduction of the detector volume has no impact on the technological objectives of PHASE 1, since the modular design with central cathode, detector materials and shieldings and auxiliary systems are independent of the total volume. The physics reach (which is a byproduct of PHASE 1 and NOT an explicit goal) will be only very partially reduced (less than a factor 2 overall) since a smaller detector volume implies also a reduced background from internal materials radioactivity. In addition, the cost reduction of CYGNO-04 of about 1⁄3 with respect to CYGNO-1 illustrated in the CDR effectively makes the overall project more financially sustainable (see CBS in the last section). In summary this document will explain: the physical motivation of the CYGNO project and the technical motivations of the downscale of the PHASE 1 to CYGNO-04, 400 liters of active volume, with respect to the demonstrator presented in the CDR; the results of R&D and the Montecarlo expectations for PHASE 0; the technical choices, procedures and the executive drawings of CYGNO-04 in the Hall F of the LNGS; safety evaluations and the interference/request to the LNGS services; Project management, WBS/WBC, WP, GANTT, ec

The CYGNO Experiment

The search for a novel technology able to detect and reconstruct nuclear and electron recoil events with the energy of a few keV has become more and more important now that large regions of high-mass dark matter (DM) candidates have been excluded. Moreover, a detector sensitive to incoming particle direction will be crucial in the case of DM discovery to open the possibility of studying its properties. Gaseous time projection chambers (TPC) with optical readout are very promising detectors combining the detailed event information provided by the TPC technique with the high sensitivity and granularity of latest-generation scientific light sensors. The CYGNO experiment (a CYGNus module with Optical readout) aims to exploit the optical readout approach of multiple-GEM structures in large volume TPCs for the study of rare events as interactions of low-mass DM or solar neutrinos. The combined use of high-granularity sCMOS cameras and fast light sensors allows the reconstruction of the 3D direction of the tracks, offering good energy resolution and very high sensitivity in the few keV energy range, together with a very good particle identification useful for distinguishing nuclear recoils from electronic recoils. This experiment is part of the CYGNUS proto-collaboration, which aims at constructing a network of underground observatories for directional DM search. A one cubic meter demonstrator is expected to be built in 2022/23 aiming at a larger scale apparatus (30 m$^3$--100 m$^3$) at a later stage

Time-based Hypermedia Processing and Pattern System

are stored in PDF, with the report number as filename. Alternatively, reports are available by post from the above address. UNIVERSIDADE DE LISBOA FACULDADE DE CI ÊNCIA