Fast Timing Detectors Research Articles

Simulation and R&D studies for the muon spectrometer at a 10 TeV Muon Collider

The Muon Collider (MC) is one of the most promising machines in terms of discovery potential. However, technological challenges arise from muon instability. This paper introduces a novel approach to muon track reconstruction designed to manage the high background levels. In this context, a fast-timing detector is required. This contribution presents the results of R&D efforts on the Picosec detector, a new generation of fast-timing Micro-Pattern Gaseous Detectors (MPGD). Specifically, the results from various test beam campaigns, focused on optimizing this technology for future experiments at a MC facility, are discussed.

Fast timing detectors for the muon system of a muon collider experiment: requirements from simulation and prototype performance

Looking at the future path of high-energy physics, a muon collider offers incomparable potential for discovery in the multi-TeV energy range. However, its development must address some relevant technological challenges, which arise from the short muon lifetime, 2.2 μs, and from the difficulty of producing large numbers of muons in groups with small emittance. The first one in particular leads to the production of the so-called Beam-induced Background (BIB), which affects the design of the machine and detector.The purpose of this contribution is to describe the expected performance of the muon system of a multipurpose muon collider detector designed to reconstruct the products of multi-TeV collisions with extreme accuracy.We are proposing a design of the muon system fully based on Micropattern Gaseous Detectors (MPGD), which foresees the combination of tracking layers based on Triple-GEM detectors, with a timing layer based on a new generation MPGD called Picosec. Picosec was developed in the last few years by the RD51 collaboration, with the aim of obtaining a fast timing (sub ns) MPGD.A dedicated R&D is ongoing to optimize such a technology for the application in a muon collider experiment, both from the detector and the mechanics point of views.This contribution will present the results obtained during the R&D of the Picosec technology for the muon collider both from laboratory tests and test beams performed in 2023. Special attention will be given to the performance obtained with different gas mixtures. Moreover, we will discuss the plans for the R&D dedicated to the muon collider.

Design and development of Low Gain Avalanche Detectors using Teledyne e2v process

The Low Gain Avalanche Detectors (LGAD) has become the preferred technological choice for fast track timing detectors in High Energy Physics applications. Additional uses of such sensors are currently being investigated, ranging from Light Detection and Ranging (LIDAR) to Low Let particle dosimetry in medical and space applications. This paper describes the development and test of LGAD devices, fabricated using a commercial process from Teledyne e2v silicon foundry. Motivation behind the project, and details of the TCAD simulations of the manufacturing process and of the electrical performances of the devices will be provided. Test results on gain and time resolution using laser injection will also be shown.

Development of the segmented plastic scintillation detector GARi for studying $r$-process nucleosynthesis at RIBF

\(\beta\)-decay properties of very neutron-rich nuclei, such as the half-life and the \(\beta\)-delayed neutron emission probabilities, play an essential role in the astrophysical rapid neutron capture process (r-process), where elements heavier than iron may be synthesized. Investigating those crucial properties has been one of the main objectives of the experimental programs at the RIKEN RI Beam Factory (RIBF). Recently, the development of a fast-timing detector system comprising a highly segmented plastic scintillation detector GARi (Gas-cell Active detector for Radioisotope decay), a neutron time-of-flight detector array, and a LaBr\textsubscript{3} detector array is being conducted for the measurement of \(\beta\)-delayed neutron emission and other related \(\beta\)-decay properties of neutron-rich nuclei at the F11 decay station of RIBF. The GARi detector has been constructed from a fast, segmented plastic scintillator coupled with nine multi-anode photomultiplier tubes (PMTs), resulting in enhanced position sensitivity. Therefore, this detector can be employed as an implantation detector and can also serve as a trigger signal in neutron time-of-flight experiments. This work details the development of the GARi detector and the results tested with the radioactive sources.

Fast timing detectors with applications in cosmic ray physics and medical science

We discuss the use of Low Gain Avalanche (LGAD) silicon detectors for two specific applications, namely measuring cosmic rays in space in collaboration with NASA] and beam properties and received doses for patients undergoing cancer treatment in flash beam therapy.

Studies of efficiency of the Kratta detectors in the deuteron breakup experiment.

An experiment focused on studies of relativistic effects in the proton-deuteron breakup reaction has been performed at Cyclotron Center Bronowice in Kraków, Poland with the use of the Kratta detectors. Thirty Kratta modules have been arranged in a planar symmetric around beam axis configuration at few selected polar angles at which significant relativistic effects have been predicted. In front of each Kratta module 4 thin plastic scintillators were installed acting as a fast timing detectors to improve a trigger system. Determination of acceptance and efficiency of the detectors is discussed.

A novel fast timing detector based on the double micro-mesh gaseous structure with reflective photocathode

Fast timing detectors play an important role in high energy physics, medical imaging and other fields. In view of wider applications and potential in the future, new detector technologies need to be investigated. A novel detection concept of fast timing based on the double micro-mesh gaseous structure with a reflective photocathode (FT-DMM) is introduced in light of its good time resolution and long-term operation. A sufficient number of photoelectrons (PEs) and a time resolution of better than 300 picoseconds (ps) for single photoelectron (SPE) are obtained by simulations, suggesting that an overall time resolution better than 100ps is feasible. The FT-DMM prototype was fabricated and tested using ultraviolet (UV) light. The gas gain can reach up to 106, while the measured time resolution of SPE is consistent with the simulated one. Furthermore, a time resolution of approximately 115ps was achieved at an average number of PEs of 5.9, and better time resolution can be expected as more PEs to be generated. These results confirm the good potential of FT-DMM as a fast timing detector for charged particle and UV light detection.

TOPS fast timing plastic scintillators: Time and light output performances

Organic plastic scintillators are largely exploited for fast timing detectors thanks to their short scintillation time with respect to inorganic crystals. Plastic scintillators are cheap to produce, light and easy to manipulate (any standard mechanical workshop can handle the cutting, polishing, etc.). Nowadays, fastest plastic scintillators available on the market are EJ-232 (Eljen Technology) and BC-422 (Saint Gobain) with a rise time of 350ps, a decay time of 1.6ns and a pulse width of 1.3ns. Foreseen the performance improvement of timing detectors based on plastic scintillators, the development of faster scintillators can give a crucial contribution. TOPS is a project focused on the development of a new class of organic scintillators producing several liquid and solid samples. Comparing the light output and the timing properties of the samples exploiting minimum ionising particles, a selection of the highly performing TOPS scintillators has been investigated and characterised. The performance achieved with TOPS samples are extremely promising: a time resolution improvement from 10 up to 35% with respect to the EJ-232 has been demonstrated. In addition, an increase of light output has been obtained for all samples with a consequent potential improvement in energy resolution measurements of a factor up to 35%.

Fast Timing Detectors and Applications in Cosmic Ray Physics and Medical Science

We use fast silicon detectors and the fast sampling method originally developed for high energy physics for two applications: cosmic ray measurements in collaboration with NASA and dose measurements during flash beam cancer treatment. The cosmic ray measurement will benefit from the fast sampling method to measure the Bragg peak where the particle stops in the silicon detector and the dose measurement is performed by counting the number of particles that enter the detector.

Beam test results of Secondary Emission Ionization Calorimetry modules at Fermilab

Increasing the collision energy and the luminosity at particle colliders requires high radiation resistance in GigaRad levels and fast-timing detectors in picosecond levels. Secondary Emission (SE) Ionization Calorimetry, a novel technology to measure the energy of electromagnetic showers and hadronic particles in extreme radiation circumstances, is such a detector. In this study, the bias circuits of Hamamatsu single anode R7761 and multi-anode R5900-00-M16 Photomultiplier Tubes (PMTs) were modified for use as novel calorimeter sensors in different SE modules. The test beam was provided by Fermi National Accelerator Laboratory, and these new sensor modules were tested with high-energy protons and shower particles at the Fermilab Test Beam Facility (FTBF). The test results showed that the SE modules are sensitive to the electromagnetic showers and they are a promising technology. Here we discuss the design, characterization tests and the beam tests of SE sensor modules, and the projections for a full-scale calorimeter.

Development of large size fast timing and radiation resistant PVT-based plastic scintillator detector

Development of large size fast timing and radiation resistant PVT-based plastic scintillator detector

Fast timing detectors for the muon system of a muon collider experiment

Fast timing detectors for the muon system of a muon collider experiment

Sub-100-picosecond time resolution from undoped and Li-doped two-dimensional perovskite scintillators

Fast hybrid organic–inorganic two-dimensional (2D) perovskite scintillators with high light yield are measured for their scintillating properties. With a light yield of 17 300 ± 2140 photons/MeV, undoped PEA2PbBr4 crystals already exhibit 100 ± 4 ps coincidence time resolution (CTR) at 511 keV excitation. However, Li-doped PEA2PbBr4 crystals have improved the light yield to 21 400 ± 2140 photons/MeV and showed sub-100 ps CTR. Such CTR values and low-cost manufacturing processes make these 2D perovskite scintillators as promising competitors for commercial lanthanide scintillators in time-of-flight positron emission tomography and for fast timing detectors.

Nature of seniority symmetry breaking in the semimagic nucleus Ru94

Direct lifetime measurements via γ−γ coincidences using a fast timing detector array consisting of LaBr3(Ce) scintillators has been applied to determine the lifetime of low-lying states in the semimagic (N=50) nucleus Ru94. The experiment was carried out as the first in a series of “FAIR-0” experiments with the DESPEC experimental setup at the Facility for Antiproton and Ion Research (FAIR). Excited states in Ru94 were populated primarily via the β-delayed proton emission of Pd95 nuclei, produced in the projectile fragmentation of an 850 MeV/nucleon Xe124 beam impinging on a 4 g/cm2Be9 target. While the deduced E2 strength for the 2+→0+ transition in the yrast cascade follows the expected behavior for conserved seniority symmetry, the intermediate 4+→2+ transition exhibits a drastic enhancement of transition strength in comparison with pure-seniority model predictions as well as standard shell model predictions in the fpg proton hole space with respect to doubly magic Sn100. The anomalous behavior is ascribed to a subtle interference between the wave function of the lowest seniority ν=2, Iπ=4+ state and that of a close-lying ν=4 state that exhibits partial dynamic symmetry. In addition, the observed strongly prohibitive 6+→4+ transition can be attributed to the same mechanism but with a destructive interference. It is noted that such effects may provide stringent tests of the nucleon-nucleon interactions employed in state-of-the-art theoretical model calculations.Received 17 October 2021Revised 17 January 2022Accepted 11 March 2022DOI:https://doi.org/10.1103/PhysRevC.105.L031304Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by Bibsam.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasIsomer decaysProton emissionProperties90 ≤ A ≤ 149Nuclear bindingTechniquesGamma ray spectroscopyNuclear structure & decaysRadiation detectorsRadioactive beamsSpectrometers & spectroscopic techniquesNuclear PhysicsAccelerators & Beams

Characterization of Low Gain Avalanche Detector Prototypes’ Response to Gamma Radiation

Motivated by the need for fast timing detectors to withstand up to 2 MGy of ionizing dose at the High Luminosity Large Hadron Collider, prototype low gain avalanche detectors (LGADs) have been fabricated in a single pad configuration, 2 × 2 arrays, and related p-i-n diodes, and exposed to Co-60 sources for study. Devices were fabricated with a range of dopant layer concentrations, and for the arrays, a variety of inter-pad distances and distances from the active area to the edge. Measurements of capacitance versus voltage and leakage current versus voltage have been made to compare pre- and post-irradiation characteristics in gain layer depletion voltage, full bulk depletion voltage, and breakdown voltage. Conclusions are drawn regarding the effects of the gammas on both surface and interface states and on their contribution to acceptor removal through non-ionizing energy loss from Compton electrons or photoelectrons. Comparison of the performances of members of the set of devices can be used to optimize gain layer parameters.

How to Improve the Performance of Fast Timing Detector

Fast timing detector is widely used for its picosecond (ps)-level timing resolution, such as Photek-PMT210 with about 50 ps at single-photon electron (SPE) mode. The time characteristics of these types of fast timing photodetectors include rise time, fall time, and electron transit time (TT) of the output signal. The test results of fast timing detector are affected by the light 7 source, the electronic device board, the data acquisition (DAQ) system, and so on. In this article, some comparative test results will be shown and discussed on the factors affecting the performance of fast timing detector.

Towards GaAs thin-film tracking detectors

Silicon-based tracking detectors have been used in several important applications, such as in cancer therapy using particle beams, and for the discovery of new elementary particles at the Large Hadron Collider at CERN. III-V semiconductor materials are an attractive alternative to silicon for this application, as they have some superior physical properties. They could meet the demands for fast timing detectors allowing time-of-flight measurements with ps resolution while being radiation tolerant and cost-efficient. As a material with a larger density, higher atomic number Z and much higher electron mobility than silicon, GaAs exhibits faster signal collection and a larger signal per μm of sensor thickness. In this work, we report on the fabrication of n-in-n GaAs thin-film devices intended to serve next-generation high-energy particle tracking detectors. Molecular beam epitaxy (MBE) was used to grow high-quality GaAs films with doping levels sufficiently low to achieve full depletion for detectors with an active thickness of 10 μm. The signal collection speed of the detector structures was assessed using the transient current technique (TCT). To elucidate the structural properties of the detector, Kelvin probe force microscopy (KPFM) was used, which confirmed the formation of the junction in the detector and revealed residual doping in the intrinsic layer. Our results suggest that GaAs thin films are suitable candidates to achieve thin and radiation-tolerant tracking detectors.

Fast timing detectors with applications in cosmic ray physics and medical science

We describe two applications concerning fast timing detectors and fast signal sampling in cosmic ray measurements in collaboration with NASA and in dose measurements for cancer treatment.

Study on fast timing MCP-PMT in magnetic fields from simulation and measurement

In recent years, fast timing detectors have attracted more and more attention in the fields of high-energy physics and nuclear medicine due to their advantages in magnetic immunity and time resolution. Through simulation analysis, we discussed in detail the reason why the gain of sensor changes with the magnetic field strength. To improve the test efficiency, we proposed a test scheme to evaluate the magnetic immunity through the shift of the signal pulse height with the magnetic field. The results show that when the sensor axis is parallel and perpendicular to the magnetic field direction, the magnetic field tolerance of the sensor is up to 5 T and 1.85 T, respectively. Besides, the time resolution of the sensor is not affected by the magnetic field strength under fixed conditions.

Plastic scintillation detectors for time-of-flight mass measurements

Fast timing detectors are an essential element in the experimental setup for time-of-flight (ToF) mass measurements of unstable nuclei. We have upgraded the scintillator detectors used in experiments at the National Superconducting Cyclotron Laboratory (NSCL) by increasing the number of photomultiplier tubes that read out their light signals to four per detector, and characterized them in a test experiment with 48Ca beam at the NSCL. The new detectors achieved a time resolution (σ) of 7.5 ps. We systematically investigated different factors that affect their timing performance. In addition, we evaluated the ability of positioning the hitting points on the scintillator using the timing information and obtained a resolution (σ) below 1 mm for well-defined beam spots.