Conveners
LGAD
- Valentina Sola (Universita e INFN Torino (IT))
- Roberta Arcidiacono (Universita e INFN Torino (IT))
LGAD
- Gianluigi Casse (University of Liverpool (GB))
- Nicolo Cartiglia (INFN Torino (IT))
Development of a new generation of 4D, low-material-budget detectors based on LGADs allows for combining high temporal and spatial resolution in one technology. Thin LGAD sensors feature a strong dependence of a deposited energy on the incident angle. Therefore, it is important to study how the incident angle of ionizing particles influences the time resolution.
The talk will report on...
The high-luminosity upgrade of the ATLAS and CMS experiments includes dedicated sub-detectors to perform the time-stamping of minimum ionizing particles (MIPs). These detectors will be exposed up to fluences in the range of 1.5 − 2.5 × 10^15 𝑛𝑒𝑞/𝑐𝑚2 at the end of their lifetime and, Low Gain Avalanche Diode (LGAD) has been chosen as their baseline detection technology. To better understand the...
The latest CNM LGAD run (R15973) was dedicated to improvement of radiations hardness by introduction of carbon in gain layer. Several different carbon doses were used. The initial gain layer doping was chosen to have operational voltage at -30C around 110-130V, thus offering good temporal resolution and good radiation hardness. The first tests after neutron irradiations up to the equivalent...
The gain of charge in LGADs (GQ) and the increase of the leakage current (GI) with respect to the generation current (Igen) are different, due to charge screening of the electric field in the gain layer, trapping-detrapping process and also possible other effects. A TCT was used to simultaneously measure GI and GQ in USFD-FBK4.0 prototypes. A special structure with PIN and LGADs very close...
In the first part of this contribution, I will report the performance of RSD sensors measured at a test beam with 4-6 GeV electrons. The sensors under study are part of the RSD2 production from FBK.
In the second part, I will illustrate the studies carried on to validate the DC-RSD read-out scheme, i.e., the performance and noise levels of amplifiers connected to the same n+ electrode.
The EXLU1 batch exited FBK clean rooms at the end of 2022, made of LGAD sensors on substrates with thicknesses ranging from 15 to 45 $\mu$m.
Different optimisation studies are addressed in the batch, namely the periphery design for thin substrates, the increase of the radiation tolerance of the gain implant through a carbon shield, and the first production of compensated LGAD, where the...
Low Gain Avalanche Detectors (LGADs) are silicon detectors with modest internal gain (up to ~50) and great time resolution (20 ps). In a broad array of fields, including particle physics (4-D tracking) and photon science (X-ray imaging), LGADs are a promising R&D path. However, due to structures required to provide electrostatic isolation between LGAD pixels, the granularity of...
In this presentation, we show the results from the comparative analysis of the charge distribution along the x-axes, measured in two segmented UFSD prototypes after their interpad regions were illuminated by fs-laser of different intensities. The segmented UFSDs are originating from two different batch productions. The two spikes recorded at the edge of p-stops in IP region, in Type 10 UFSD...
In this presentation we report our research on W7 UFSD Type10 (2 p-stops + bias ring) and W7 UFSD Type 4 (with only bias ring in interpad region) prototype samples. Those results will be compared to the results obtained on W11 UFSD Type 10. Those UFSD prototype samples are not standard UFSD, they are produced in TI-LGAD batch as reference samples.
Wafer W7 and W11 differ in gain and in...
In this presentation, we report our findings on the impact of radiation-induced bulk defects on the previously reported phenomenon of strong charge multiplication in the inter-pad (IP) region of non-irradiated Trenched Low-Gain Avalanche Detectors (LGADs) that utilize two trenches as isolation structures. A comparative analysis is conducted between the results obtained from the study of...
This presentation aims to provide an update on the recently completed AC-LGAD run at CNM. We begin by showing the electrical characterization of the produced wafers by IV and CV measurements. Several devices with different pad configurations and sizes were subjected to extensive TCT measurements. The TCT measurements reveal that the signal weakens as the laser is moved further away from the AC...
Energy deposition of highly energetic particles was simulated in LGADs with GEANT4. The simulation step was adjusted to simulate deposits over the entire detector depth in <10 um steps. The signal formation was simulated with KDetSim using the parameters of HPK-P2 LGAD prototypes for ETL/HGTD and JSI model for impact ionization. The induced current pulses were convoluted with transfer...
The partial activation of the boron atoms implanted in the gain layer region will be investigated to mitigate the effect of radiation on the gain implant in LGAD sensors. Atoms of boron in the gain layer volume left as interstitials can interact with other impurities present in the silicon lattice, preventing the removal of boron atoms from substitutional positions.
The goal of the project is...
To better understand the performances of LGADs in terms of collected charge, it is important to know with high accuracy the models that predict the avalanche mechanism of charge carriers. Several literature models are not able to predict with very high precision the evolution of the avalanche multiplication in LGAD sensors, showing discrepancies with experimental data. This truth is driving...
