arXiv subjects

Jihane Maalmi

Publications and source records attributed to Jihane Maalmi.

7 recordsLinked to original sources

arXiv2026

Studying the GRAiNITA concept: first test beam results

Data collected over a two-day period in June 2024 at the CERN SPS H9 test beam using a small-scale GRAiNITA prototype have been analyzed to characterize the detector's energy resolution performance. The measurements allow for a first estimate of the constant term associated with detector non-uniformity. Although the evaluation is limited by the small prototype size and the use of pion beams, the results indicate that the non-uniformity-related constant term is significantly below 1%. Furthermore, the test-beam data confirm that the contribution to the energy resolution arising from photo-electron statistics is approximately 1%/sqrt(E). These findings validate the expected calorimetric performance of the GRAiNITA concept and provide important input for the design and optimization of future full-scale detectors.

physics.ins-det↗

arXiv2025

SPIDER, a Waveform Digitizer ASIC for picosecond timing in LHCb PicoCal

We present the architecture, design and first test results of SPIDER, the first prototype of a TSMC CMOS 65 nm ASIC designed for the time measurement path of LHCb Electromagnetic Calorimeter after LS4 Upgrade. The main requirements for the readout of this detector are a time resolution below 15 ps rms above 5 GeV, and a channel occupancy up to 30\% (12 Mevent/s). The first prototype called SPIDER\_V0 is a 2-channel waveform digitizer locked on the LHC clock allowing precise time reconstruction by digital algorithms. The architecture is based on 2 DLLs in series controlling respectively the phase of the sampling window and the sampling frequency, the latter covering the range between 2 and 20 GS/s. Each self-triggering channel houses 8 banks of 32 analog memory cells and a massively parallel Wilkinson ADC for conversion at 5 GHz over 10 bits with a maximal conversion time of 200 ns. SPIDER targets not only LHCb, but all fast detectors mounted on current and future accelerators. Its sampling frequency can indeed be adjusted to different signal risetimes. Its main frequency of 40 MHz could even be eventually locked to another value by modifying only one of the DLLs in the chip design.

physics.ins-det↗

arXiv2025

A Proposal for the Lohengrin Experiment to Search for Dark Sector Particles at the ELSA Accelerator

We present a proposal for a future light dark matter search experiment at the Electron Stretcher Accelerator ELSA in Bonn: Lohengrin. It employs the fixed-target missing momentum based technique for searching for dark-sector particles. The Lohengrin experiment uses a high intensity electron beam that is shot onto a thin target to produce mainly SM bremsstrahlung and - in rare occasions - possibly new particles coupling feebly to the electron. A well motivated candidate for such a new particle is the dark photon, a new massive gauge boson arising from a new gauge interaction in a dark sector and mixing kinetically with the standard model photon. The Lohengrin experiment is estimated to reach sensitivity to couplings small enough to explain the relic abundance of dark matter in various models for dark photon masses between approximately 1 MeV and approximately 100 MeV.

hep-ex↗

arXiv2024

Characterization of the BOLDPET optical prototype, an innovative Cherenkov detector for 511 keV $γ$ radiation

In the present work we describe the design, construction, and testing of the optical prototype developed for the BOLDPET project, with the objective of creating a PET detection module with high spatial and time resolution. The BOLDPET technology uses an innovative detection liquid, trimethylbismuth, for detecting 511 keV $γ$-quanta resulting from positron annihilation. The optical signal is exclusively produced through the Cherenkov mechanism, and the produced photons are detected using Planacon microchannel-plate photomultiplier. We achieve an excellent time resolution of 150 ps (FWHM) within a sizable detection volume measuring 55 mm x 55 mm x 25 mm. Through detailed Geant4 simulations, we examine the limiting factors affecting time resolution and explore potential avenues for improvement. Furthermore, we demonstrate the feasibility of coarse 2D localization of interactions using the optical signal alone, achieving a precision of about 5-8 mm (FWHM) within the homogeneous detection volume.

physics.ins-det↗

arXiv2023

Detailed simulation for the ClearMind prototype detection module and event reconstruction using artificial intelligence

The ClearMind project aims to develop the TOF-PET position sensitive detection module optimized for the time resolution, spatial resolution, and detection efficiency. For this, the ClearMind project uses a large (59 $\times$ 59 mm$^2$) monolithic PbWO$_4$ (PWO) scintillating crystal with a bialkali photo-electric layer deposited directly on the crystal. Scintillation and Cherenkov photons result together from the 511 keV gamma-ray interation into the PWO crystal. A micro-channel plate photomultiplier tube (MCP-PMT) encapsulating the PWO crystal amplifies photoelectrons generated at the photocathode, and the corresponding anode signals are collected through the transmission lines read out at both ends and digitized by a SAMPIC module. In this work, we present a realistic Geant4 simulation of the ClearMind prototype detector, including the propagation of the visible photons in the crystal, the modelling of a realistic response of the photocathode and of the PMT, and the propagation of the electrical signals over the transmission lines. The reconstruction of the gamma conversion in the detector volume is performed from the signals registered at both ends of the transmission lines. We compare the reconstruction precision of a statistical algorithm against machine learning algorithms developed using the TMVA package. We expect to reach a spatial resolution down to a few mm$^3$ (FWHM). Finally, we will discuss prospects for the ClearMind detector.

physics.ins-det↗

arXiv2021

Mass production and characterization of 3-inch PMTs for the JUNO experiment

26,000 3-inch photomultiplier tubes (PMTs) have been produced for Jiangmen Underground Neutrino Observatory (JUNO) by the Hainan Zhanchuang Photonics Technology Co., Ltd (HZC) company in China and passed all acceptance tests with only 15 tubes rejected. The mass production began in 2018 and elapsed for about 2 years at a rate of $\sim$1,000~PMTs per month. The characterization of the PMTs was performed in the factory concurrently with production as a joint effort between HZC and JUNO. Fifteen performance parameters were tracked at different sampling rates, and novel working strategies were implemented to improve quality assurance. This constitutes the largest sample of 3-inch PMTs ever produced and studied in detail to date.

physics.ins-det↗

arXiv2016

Measurements of timing resolution of ultra-fast silicon detectors with the SAMPIC waveform digitizer

The SAMpler for PICosecond time (SAMPIC) chip has been designed by a collaboration including CEA/IRFU/SEDI, Saclay and CNRS/LAL/SERDI, Orsay. It benefits from both the quick response of a time to digital converter and the versatility of a waveform digitizer to perform accurate timing measurements. Thanks to the sampled signals, smart algorithms making best use of the pulse shape can be used to improve time resolution. A software framework has been developed to analyse the SAMPIC output data and extract timing information by using either a constant fraction discriminator or a fast cross-correlation algorithm. SAMPIC timing capabilities together with the software framework have been tested using pulses generated by a signal generator or by a silicon detector illuminated by a pulsed infrared laser. Under these ideal experimental conditions, the SAMPIC chip has proven to be capable of timing resolutions down to 4 ps with synthesized signals and 40 ps with silicon detector signals.

physics.ins-det↗