Search results for " Io"

Minijet initial state of heavy-ion collisions from next-to-leading order perturbative QCD

2014

A Monte Carlo simulation for the elastic energy loss of high-energy partons in a strongly interacting medium

2012

Analisi della Conoscenza del rischio da radiazioni ionizzanti tra giovani radiologi e studenti in medicina. Indagine mediante questionario

2010

A GEM-TPC in twin configuration for the Super-FRS tracking of heavy ions at FAIR

2018

The GEM-TPC [1] described herein will be part of the standard beam-diagnostics equipment of the Super-FRS [2] . This chamber will provide tracking information for particle identification at rates up to 1 MHz on an event-by-event basis. The key requirements of operation for these chambers are: close to 100% tracking efficiency under conditions of high counting rate, spatial resolution below 1 mm and a superb large dynamic range covering projectiles from Z=1 up to Z=92. The current prototype consists of two GEM-TPCs inside a single vessel, which are operating independently and have electrical drift fields in opposite directions. The twin configuration is done by flipping one of the GEM-TPCs o…

Transport and extraction of radioactive ions stopped in superfluid helium

2003

A new approach to convert a high energy beam to a low energy one, which is essential for the next generation radioactive ion beam facilities, has been proposed and tested at Jyvaskyla, Finland. An open Ra-223 alpha-decay-recoil source has been used to produce radioactive ions in superfluid helium. The alpha spectra demonstrate that the recoiling Rn-219 ions have been extracted out of liquid helium. This first observation of the extraction of heavy positive ions across the superfluid helium surface was possible thanks to the high sensitivity of radioactivity detection. An efficiency of 36% was obtained for the ion extraction out of liquid helium. (C) 2003 Elsevier Science B.V. All rights res…

Use of fragmentation beams at LNS with CHIMERA detector

2012

The recent intensity upgrade of the LNS fragmentation beam is discussed. The available beams, the tagging procedures and details on the beam quality are reported. The experimental program started with the CHIMERA detector using such beams is also discussed with preliminary results and future perspectives. © Owned by the authors, 2012.

Sorption and mechanism studies of Cu2+, Sr2+ and Pb2+ ions on mesoporous aluminosilicates/zeolite composite sorbents

2020

The research aimed to develop a novel mesoporous aluminosilicate/zeolite composite by the template co-precipitation method. The effect of aluminosilicate (AlSi) and zeolite (NaY) on the basic properties and adsorption capacity of the resultant composite was conducted at different mass ratios of AlSi/NaY (i.e., 5/90, 10/80, 15/85, 20/80, and 50/50). The adsorption characteristics of such composite and its feedstock materials (i.e., aluminosilicates and zeolite) towards radioactive Sr2+ ions and toxic metals (Cu2+ and Pb2+ ions) in aqueous solutions was investigated. Results indicated that BET surface area (SBET), total pore volume (VTotal), and mesopore volume (VMeso) of prepared materials f…

Radiofrequency and 2.45 GHz electron cyclotron resonance H− volume production ion sources

2016

The volume production of negative hydrogen ions (H-) in plasma ion sources is based on dissociative electron attachment (DEA)to rovibrationally excited hydrogen molecules(H2), which is a two-step process requiring both, hot electrons for ionization, and vibrational excitation of the H2 and cold electrons for the H- formation through DEA. Traditionally H- ion sources relying on the volume production have been tandem-type arc discharge sources equipped with biased filament cathodes sustaining the plasma by thermionic electron emission and with a magnetic filter separating the main discharge from the H- formation volume. The main motivation to develop ion sources based on radiofrequency (RF) o…

Column Adsorption Studies for the Removal of Ammonium Using Na-Zeolite-Based Geopolymers

2022

The aim of this study was to examine the removal of ammonium ions from a synthetic model solution by using Na-zeolite-based geopolymers. Na-zeolite (=analcime) is a residue from mining industry. Three adsorbents were prepared from Na-zeolite using different production steps and metakaolin as a blending agent. These novel adsorbents were investigated in a fixed-bed column system where the effects of different flow rates with the initial ammonium concentration of 40 mg/L were studied. The Thomas, Bohart–Adams and Yoon–Nelson breakthrough curve models fitted well with the experimental data with a high R2 value. After adsorption experiments, adsorbents were regenerated using a mixture of 0.2 M …

Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at √s, √sNN = 5.02 TeV

2021

Jet fragmentation transverse momentum (jT) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at √sNN = 5.02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT algorithm with resolution parameter R = 0.4 in the pseudorapidity range |η| < 0.25. The jT values are calculated for charged particles inside a fixed cone with a radius R = 0.4 around the reconstructed jet axis. The measured jT distributions are compared with a variety of parton-shower models. Herwig and Pythia 8 based models describe the data well for the higher jT region, while they underestimate the low…