156 research outputs found
Si-Gly-CD-PdNPs as a hybrid heterogeneous catalyst for environmentally friendly continuous flow Sonogashira cross-coupling
Highly-efficient caffeine recovery from green coffee beans under ultrasound-assisted SC-CO2 extraction
Natural caffeine from decaffeination processes is widely used by pharmaceutical, cosmetic and soft-drink industries. Supercritical CO2 extraction (SFE–CO2) is extensively exploited industrially, and one of its most representative applications is the decaffeination process, which is a greener alternative to the use of organic solvents. Despite its advantages, extraction kinetics are rather slow near the CO2 critical point, meaning that improvements are highly sought after. The effect exerted by a combination of SFE–CO2 and ultrasound (US–SFE–CO2) has been investigated in this preliminary study, with the aim of improving mass transfer and selectivity in the extraction of caffeine from green coffee beans. This hybrid technology can considerably enhance the extraction efficiency and cut down process time. Further studies are in progress to demonstrate the complete decaffeination of green coffee beans of different types and origins
First experimental results of the spatial resolution of RSD pad arrays read out with a 16-ch board
Resistive Silicon Detectors (RSD, also known as AC-LGAD) are innovative silicon sensors, based on the LGAD technology, characterized by a continuous gain layer that spreads across the whole sensor active area. RSDs are very promising tracking detectors, thanks to the combination of the built-in signal sharing with the internal charge multiplication, which allows large signals to be seen over multiple read-out channels. This work presents the first experimental results obtained from a 34 array with 200~\mum~pitch, coming from the RSD2 production manufactured by FBK, read out with a 16-ch digitizer. A machine learning model has been trained, with experimental data taken with a precise TCT laser setup, and then used to predict the laser shot positions, finding a spatial resolution of ~ 5.5 um
A new Low Gain Avalanche Diode concept: the double-LGAD
This paper describes the new concept of the double-LGAD. The goal is to
increase the charge at the input of the electronics, keeping a time resolution
equal or better than a standard (single) LGAD; this has been realized by adding
the charges of two coupled LGADs while still using a single front-end
electronics. The study here reported has been done starting from single LGAD
with a thickness of 25 \textmu{m}, 35 \textmu{m} and 50 \textmu{m}.Comment: arXiv admin note: text overlap with arXiv:2208.0571
Development of gamma insensitive silicon carbide diagnostics to qualify intense thermal and epithermal neutron fields
The e_LiBANS project aims at creating accelerator based compact neutron
facilities for diverse interdisciplinary applications. After the successful
setting up and characterization of a thermal neutron source based on a medical
electron LINAC, a similar assembly for epithermal neutrons has been developed.
The project is based on an Elekta 18 MV LINAC coupled with a
photoconverter-moderator system which deploys the ({\gamma},n) photonuclear
reaction to convert a bremsstrahlung photon beam into a neutron field. This
communication describes the development of novel diagnostics to qualify the
thermal and epithermal neutron fields that have been produced. In particular, a
proof of concept for the use of silicon carbide photodiodes as a thermal
neutron rate detector is presented.Comment: 10 pages, 10 figures, accepted for publication to JINST on the 17th
April 202
The second production of RSD (AC-LGAD) at FBK
In this contribution we describe the second run of RSD (Resistive AC-Coupled
Silicon Detectors) designed at INFN Torino and produced by Fondazione Bruno
Kessler (FBK), Trento. RSD are n-in-p detectors intended for 4D particle
tracking based on the LGAD technology that get rid of any segmentation implant
in order to achieve the 100% fill-factor. They are characterized by three
key-elements, (i) a continuous gain implant, (ii) a resistive n-cathode and
(iii) a dielectric coupling layer deposited on top, guaranteeing a good spatial
reconstruction of the hit position while benefiting from the good timing
properties of LGADs. We will start from the very promising results of our RSD1
batch in terms of tracking performances and then we will move to the
description of the design of the RSD2 run. In particular, the principles
driving the sensor design and the specific AC-electrode layout adopted to
optimize the signal confinement will be addressed
High-Precision 4D Tracking with Large Pixels using Thin Resistive Silicon Detectors
The basic principle of operation of silicon sensors with resistive read-out
is built-in charge sharing. Resistive Silicon Detectors (RSD, also known as
AC-LGAD), exploiting the signals seen on the electrodes surrounding the impact
point, achieve excellent space and time resolutions even with very large
pixels. In this paper, a TCT system using a 1064 nm picosecond laser is used to
characterize sensors from the second RSD production at the Fondazione Bruno
Kessler. The paper first introduces the parametrization of the errors in the
determination of the position and time coordinates in RSD, then outlines the
reconstruction method, and finally presents the results. Three different pixel
sizes are used in the analysis: 200 x 340, 450 x 450, and 1300 x 1300
microns^2. At gain = 30, the 450 x 450 microns^2 pixel achieves a time jitter
of 20 ps and a spatial resolution of 15 microns concurrently, while the 1300 x
1300 microns^2 pixel achieves 30 ps and 30 micron, respectively. The
implementation of cross-shaped electrodes improves considerably the response
uniformity over the pixel surface.Comment: 28 pages, 23 figures submitted to NIM
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