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The amount of energy released by a nuclear recoil ionizing the atoms of the active volume of detection appears “quenched” compared to an electron of the same kinetic energy. This different behavior in ionization between electrons and nuclei is described by the Ionization Quenching Factor (IQF) and it plays a crucial role in direct dark matter searches. For low kinetic energies (below 50keV), IQF measurements deviate significantly from common models used for theoretical predictions and simulations. We report measurements of the IQF for proton, an appropriate target for searches of Dark Matter candidates with a mass of approximately 1GeV, with kinetic energies in between 2keV and 13keV in 100mbar of methane. We used the Comimac facility in order to produce the motion of nuclei and electrons of controlled kinetic energy in the active volume, and a NEWS-G SPC to measure the deposited energy. The Comimac electrons are used as a reference to calibrate the detector with 7 energy points. A detailed study of systematic effects led to the final results well fitted by IQF(EK)=EKα/(β+EKα) with α=0.70±0.08 and β=1.32±0.17. In agreement with some previous works in other gas mixtures, we measured less ionization energy than predicted from SRIM simulations, the difference reaching 33% at 2keV.

The experimental requirements in current and near-future accelerators and experiments have stimulated intense interest in R&D of detectors with high precision timing capabilities, resulting in novel instrumentation. During the R&D phase, the timing information is usually extracted from the signal using the full waveform collected with fast oscilloscopes; this method produces a large amount of data and it becomes impractical when the detector has many channels. Towards practical applications, the data acquisition should be undertaken by dedicated front-end electronic units. The selected technology should retain the signal timing characteristics and consequently the timing resolution on the particle’s arrival time. We investigate the adequacy of the Leading-edge discrimination timing technique to achieve timing with a precision in the order of tens of picosecond with novel gaseous detectors. The method under investigation introduces a “time-walk” which impinges on the timing resolution. We mitigate the effect of time-walk using three different approaches; the first based on multiple Time-over-Threshold, the second based on multiple Charge-over-Threshold information and the third uses artificial Neural Network techniques. The results of this study prove the feasibility of the methods and their ability to achieve a timing resolution comparable to that obtained using the full waveforms.

The Astroneu cosmic ray telescope is a small scale hybrid array consisting of both scintillator counters and electromagnetic radiation detectors in the radio-wave frequency (RF) band (antennas). Astroneu was installed and operated in the area of the Hellenic Open University (HOU) campus near the city of Patras in Greece. In the present development phase, the Astroneu telescope includes two stations consisting of 3 scintillation detectors modules (SDM) and one RF antenna while a third station includes 3 particle detectors and 4 RF antennas (3SDM-4RF). In this context we present the resent results from both the 3SDM-4RF autonomous station and simulations related to the estimation of the direction of the electric field emitted during the air shower development. The electric field measured in the ground level is the superposition of the two dominant emission mechanism, the time depended transverse current induced by the geomagnetic field and the net negative charge variation at the shower front. Since the electric field emitted by the two contributions is polarized in different directions the measured electric field in the ground encloses information about the charge-excess to geomagnetic ratio (CGR). Furthermore the orientation of the electric field emitted by charge-excess mechanism is strongly depends from the distance to the shower core (the intersection of the shower axis with the ground level). In this study we use the core information as reconstructed using the radio data and simulations. The estimated charge-excess to geomagnetic ratio is in agreement with previous studies which reveals that the shower core reconstruction method is efficient. Finally we report on that CGR measurements can be used for an efficient noise rejection in a future self trigger mode

The Astroneu cosmic ray telescope is a distributed hybrid array consisting of both scintillator counters and RF antenna detectors used for the detection of extensive air showers (EAS). The array is deployed at the Hellenic Open University campus, on the outskirts of the urban area of Patras in Greece. In the present development phase, the Astroneu telescope includes two stations consisting of 3 scintillation detectors modules (SDM) and one RF antenna while a third station includes 3 particle detectors and 4 RF antennas (3SDM-4RF). In each station, the RF-detectors are operating receiving a common trigger upon a 3-fold coincidence between the particle detectors of the station. In this study we present recent results from the 3SDM-4RF autonomous station related to the estimation of the direction of the incoming cosmic air shower using only the timing information from the 4 RF detectors. The directions of the reconstructed showers using the RF timing are in agreement with the corresponding results using the SDMs timing as well as with the simulation predictions. This verifies that the RF signal emitted from EAS originating form Ultra High Energy Cosmic Rays (UHECR), can be detected even in areas with strong electromagnetic background.

Precise in-situ measurements of the neutron flux in underground laboratories is crucial for direct dark matter searches, as neutron induced backgrounds can mimic the typical dark matter signal. The development of a novel neutron spectroscopy technique using Spherical Proportional Counters is investigated. The detector is operated with nitrogen and is sensitive to both fast and thermal neutrons through the 14N(n, α)11B and 14N(n, p)14C reactions. This method holds potential to be a safe, inexpensive, effective, and reliable alternative to 3He-based detectors. Measurements of fast and thermal neutrons from an Am-Be source with a Spherical Proportional Counter operated at pressures up to 2 bar at Birmingham are discussed.

Precise in-situ measurements of the neutron flux in underground laboratories is crucial for direct dark matter searches, as neutron induced backgrounds can mimic the typical dark matter signal. The development of a novel neutron spectroscopy technique using Spherical Proportional Counters is investigated. The detector is operated with nitrogen and is sensitive to both fast and thermal neutrons through the 14 N(n, α ) 11 B and 14 N(n, p) 14 C reactions. This method holds potential to be a safe, inexpensive, effective, and reliable alternative to 3 He-based detectors. Measurements of fast and thermal neutrons from an Am-Be source with a Spherical Proportional Counter operated at pressures up to 2 bar at Birmingham are discussed.

The Hellenic Open University Cosmic Ray Telescope consists of three autonomous stations installed at the University Campus in the city of Patras. Each station comprises three large (≈ 1 m 2 ) plastic scintillators and one or more Codalema type RF antennas detecting Extensive Air Showers (EAS), originating from primary particles with energy greater than 10 TeV. The operation and the performance of the Telescope is presented briefly, emphasising the educational activities foreseen in the framework of the HEllenic LYceum Cosmic Observatories Network (HELYCON).

The PICOSEC-Micromegas detector was developed for precise timing of the arrival of charged particles with a resolution bellow 30 ps. This contribution, after a brief introduction presents results concerning the PICOSEC-Micromegas response to single photoelectrons, estimation of the photoelectron yield of various photocathode types, as well as its performance to time the arrival of test beam muons. In addition, results based on detailed simulation studies and a stochastic model developed for the understanding of the detector are presented. Finally, results of studies related to the development of large scale PICOSEC-Micromegas detector for practical applications are also presented, in particular, the timing performance of a multi-channel PICOSEC prototype.

Detectors with a time resolution of 20-30 ps and a reliable performance in high particles flux environments are necessary for an accurate vertex separation in future HEP experiments. The PICOSEC-Micromegas detector concept is a Micro-Pattern Gaseous Detector (MPGD) based solution addressing this particular challenge. The PICOSEC-Micromegas concept is based on a Micromegas detector coupled to a Cherenkov radiator and a photocathode. In this detector concept, all primary electrons are initiated in the photocathode and the time jitter fluctuations are reduced. Different resistive anode layers have been tested with the goal of preserving a stable detector operation in a high intensity pion beam. One important characteristic of a gaseous detector in a high flux environment is the ion backflow (IBF). That can cause damage to more fragile photocathode materials like CsI. Various types of photocathode materials have been tested in order to find a robust solution against IBF bombardment.

After the forthcoming upgrade of the LHC accelerator at CERN, its luminosity will increase up to 7.5 × 10 34 cm −2 s −1 . That will raise the readout rates and the background data to unmanageable levels for the existing ATLAS muon spectrometer. The ATLAS collaboration has proposed to replace the present small wheel muon detector with the New Small Wheel (NSW) to surpass those limitations. The new wheels consist of Micromegas (MM) and small-strip Thin Gap Chambers (sTGC). The first technology aims for precision tracking, and the last one for trigger purposes. Each wheel will be equipped with eight small and eight large sectors, while each sector will have a double MM wedge surrounded by sTGC wedges. The MM detectors for the NSW will be the largest developed Micro Pattern Gaseous Detector (MPGD) as they will cover an area up to 1280 m 2 . During detectors’ manufacture have been used various custom materials (PCBs, mesh) and innovative construction techniques. This paper describes the MM drift panels production at Aristotle University of Thessaloniki laboratory. Then will be presented resolution results of the MM detectors with cosmic-ray tests at CERN facilities.