78 research outputs found
The future search for low-frequency axions and new physics with the FLASH resonant cavity experiment at Frascati National Laboratories
We present a proposal for a new experiment, the FINUDA magnet for Light Axion
SearcH (FLASH), a large resonant-cavity haloscope in a high static magnetic
field which is planned to probe new physics in the form of dark matter (DM)
axions, scalar fields, chameleons, hidden photons, as well as high frequency
gravitational waves (GWs). Concerning the QCD axion, FLASH will search for
these particles as the DM in the mass range (0.49-1.49) ueV, thus filling the
mass gap between the ranges covered by other planned searches. A dedicated
Microstrip SQUID operating at ultra-cryogenic temperatures will amplify the
signal. The frequency range accessible overlaps with the Very High Frequency
(VHF) range of the radio wave spectrum and allows for a search in GWs in the
frequency range (100-300) MHz. The experiment will make use of the cryogenic
plant and magnet of the FINUDA experiment at INFN Frascati National
Laboratories near Rome (Italy); the operations needed to restore the
functionalities of the apparatus are currently underway. We present the setup
of the experiment and the sensitivity forecasts for the detection of axions,
scalar fields, chameleons, hidden photons, and GWs
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 1â3 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--100 m) at a later
stage
Geometric beam coupling impedance of LHC secondary collimators
The High Luminosity LHC project is aimed at increasing the LHC luminosity by an order of magnitude. One of the key ingredients to achieve the luminosity goal is the beam intensity increase. In order to keep under control beam instabilities and to avoid excessive power losses a careful design of new vacuum chamber components and an improvement of the present LHC impedance model are required. Collimators are the main impedance contributors. Measurements with beam have revealed that the betatron coherent tune shifts were by about a factor of 2 higher with respect to the theoretical predictions based on the current model. Up to now the resistive wall impedance has been considered as the major impedance contribution for collimators. By carefully simulating their geometric impedance we show that for the graphite collimators with half-gaps higher than 10 mm the geometric impedance exceeds the resistive wall one. In turn, for the tungsten collimators the geometric impedance dominates for all used gap values. Hence, including the geometric collimator impedance into the LHC impedance model enabled us to reach a better agreement between the measured and simulated collimator tune shifts
Geometric beam coupling impedance of LHC secondary collimators
The High Luminosity LHC project is aimed at increasing the LHC luminosity by an order of magnitude. One of the key ingredients to achieve the luminosity goal is the beam intensity increase. In order to keep beam instabilities under control and to avoid excessive power losses a careful design of new vacuum chamber components and an improvement of the present LHC impedance model are required. Collimators are among the major impedance contributors. Measurements with beam have revealed that the betatron coherent tune shifts were higher by about a factor of 2 with respect to the theoretical predictions based on the LHC impedance model up to 2012. In that model the resistive wall impedance has been considered as the dominating impedance contribution for collimators. By carefully simulating also their geometric impedance we have contributed to the update of the LHC impedance model, reaching also a better agreement between the measured and simulated betatron tune shifts. During the just ended LHC Long Shutdown I (LSI), TCS/TCT collimators were replaced by new devices embedding BPMs and TT2-111R ferrite blocks. We present here preliminary estimations of their broad-band impedance, showing that an increase of about 20% is expected in the kick factors with respect to previous collimators without BPMs. © 2015 Elsevier B.V. All rights reserved
Fetal phonocardiogram denoising by wavelet transformation: Robustness to noise
Fetal phonocardiography (fPCG) is a clinical test to
assess fetal wellbeing during pregnancy, labor and
delivery. Still, its interpretation may be jeopardized by
the presence of noise. Specifically, fPCG is typically
corrupted by maternal heart and body organs sounds,
fetal movements noise and surrounding environment
noise. Thus, appropriate filtering procedures have to be
applied in order to make fPCG clinically usable. Wavelet
transformation (WT) has been proposed to filter fPCG;
however, WT robustness to noise remains unknown.
Thus, aim of the present work is to evaluate WT ability
and robustness to denoise fPCG characterized by varying
signal-to-noise ratios (SNR). To this aim a filtering
procedure based on Coiflets mother wavelet (4th order, 7
levels of decomposition) was applied to 37 fPCG
simulated tracings, all available in the Simulated Fetal
PCGs database by Physionet. Original SNR values
ranged from -1.38 dB to 4.54 dB; after application of
WT-filtering procedure to fPCG, SNR increased
significantly, ranging from 12.95 dB to 17.94 dB (P<10-
14). Moreover, SNR values before and after filtering were
associated by a low correlation (Ï=0.4; P=0.01).
Eventually, WT filtering introduced no fPCG signal delay
and left heart rate unaltered. Thus, WT filtering is a
suitable and robust technique to denoise fPCG signals
Fiber Optic Sensors for Space Missions
Fiber optic sensors offer several advantages over conventional ones such as the immunity from electromagnetic interferences and the possibility of multiplexing many of them along the same fiber. Such sensors can be used to monitor local deformations on or inside the structures. In the paper will be mentioned techniques that can be used for embedding those sensors into several types of materials and possible applications in the field of Structural Health Monitoring (SHM). However the main objective is to show applications is in the field of scientific space experiments where precise position monitoring of particle detectors or of optical instrument can be crucial for the success of the mission. A real time position monitoring system based on fiber optic sensors is presented. The experimental results are compared with a conventional optical technique. © 2003 IEEE
Identification of low energy nuclear recoils in a gas TPC with optical readout
The search for a novel technology able to detect and reconstruct nuclear
recoil events in the keV energy range has become more and more important as
long as vast regions of high mass WIMP-like Dark Matter candidate have been
excluded. Gaseous Time Projection Chambers (TPC) with optical readout are very
promising candidate combining the complete event information provided by the
TPC technique to the high sensitivity and granularity of last generation
scientific light sensors. A TPC with an amplification at the anode obtained
with Gas Electron Multipliers (GEM) was tested at the Laboratori Nazionali di
Frascati. Photons and neutrons from radioactive sources were employed to induce
recoiling nuclei and electrons with kinetic energy in the range [1-100] keV. A
He-CF4 (60/40) gas mixture was used at atmospheric pressure and the light
produced during the multiplication in the GEM channels was acquired by a high
position resolution and low noise scientific CMOS camera and a photomultiplier.
A multi-stage pattern recognition algorithm based on an advanced clustering
technique is presented here. A number of cluster shape observables are used to
identify nuclear recoils induced by neutrons originated from a AmBe source
against X-ray 55Fe photo-electrons. An efficiency of 18% to detect nuclear
recoils with an energy of about 6 keV is reached obtaining at the same time a
96% 55Fe photo-electrons suppression. This makes this optically readout gas TPC
a very promising candidate for future investigations of ultra-rare events as
directional direct Dark Matter searches
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