103 research outputs found
Intense terahertz pulses from SPARC-LAB coherent radiation source
The linac-based Terahertz source at the SPARC_LAB test facility is able to gene
rate highly intense Terahertz broadband
pulses
via
coherent transition radiation (CTR) from high brightness electron beams. The THz pulse duration is typically
down to 100 fs RMS and can be tuned through the electron bunch duration and shaping. The measured stored energy in a
single THz pulse has reached 40
μ
J, which corresponds to a peak
electric field of 1.6 MV/cm at the THz focus. Here we
present the main features, in particular spatial and sp
ectral distributions and energy
characterizations of the
SPARC_LAB THz source, which is very competitive for investigations in Condensed Matter, as well as a valid tool for
electron beam longitudinal diagnostics
Cryogenic Detectors for Rare Alpha Decay Search: A New Approach
The detection of Sm alpha decay with a precise measured half-life of and a Q-value of 1987.3 0.5 keV was achieved by a new experimental approach, where a conventional ZnWO scintillating crystal doped with enriched Sm isotope is operated as a cryogenic scintillating bolometer (phonon and light channel) at mK-temperatures
Beam manipulation for resonant plasma wakefield acceleration
Plasma-based acceleration has already proved the ability to reach ultra-high accelerating gradients. However
the step towards the realization of a plasma-based accelerator still requires some e
ff ort to guarantee high brightness beams, stability and reliability. A significant improvement in the efficiency of PWFA has been
demonstrated so far accelerating a witness bunch in the wake of a higher charge driver bunch. The transformer
ratio, therefore the energy transfer from the driver to the witness beam, can be increased by resonantly exciting
the plasma with a properly pre-shaped drive electron beam. Theoretical and experimental studies of beam
manipulation for resonant PWFA will be presented her
Delivery status of the ELI-NP gamma beam system
International audienceThe ELI-NP GBS is a high intensity and monochromatic gamma source under construction in Magurele (Romania). The design and construction of the Gamma Beam System complex as well as the integration of the technical plants and the commissioning of the overall facility, was awarded to the Eurogammas Consortium in March 2014. The delivery of the facility has been planned in for 4 stages and the first one was fulfilled in October 31st 2015. The engineering aspects related to the delivery stage 1 are presented
Grand Rounds: Could Occupational Exposure to n-Hexane and Other Solvents Precipitate Visual Failure in Leber Hereditary Optic Neuropathy?
CONTEXT: Leber hereditary optic neuropathy (LHON) is a maternally inherited loss of central vision related to pathogenic mutations in the mitochondrial genome, which are a necessary but not sufficient condition to develop the disease. Investigation of precipitating environmental/occupational (and additional genetic) factors could be relevant for prevention. CASE PRESENTATION: After a 6-month period of occupational exposure to n-hexane and other organic solvents, a 27-year-old man (a moderate smoker) developed an optic neuropathy. The patient had a full ophthalmologic and neurologic investigation, including standardized cycloergometer test for serum lactic acid levels and a skeletal muscle biopsy. His exposure history was also detailed, and he underwent genetic testing for LHON mitochondrial DNA mutations. The patient suffered a sequential optic neuropathy with the hallmarks of LHON and tested positive for the homoplasmic 11778G → A/ND4 mutation. Routine laboratory monitoring revealed increased concentrations of urinary 2.5 hexandione (n-hexane metabolite) and hippuric acid (toluene metabolite) in the period immediately preceding the visual loss. DISCUSSION: In a subject carrying an LHON mutation, the strict temporal sequence of prolonged appreciable occupational exposure followed by sudden onset of visual loss must raise a suspicion of causality (with a possible further interaction with tobacco smoke). RELEVANCE: In this article, we add to the candidate occupational/environmental triggers of LHON and highlight the need for appropriate case–control (and laboratory) studies to validate the causal effect of mixed toxic exposures
Monitoring of indoor bioaerosol for the detection of SARS-CoV-2 in different hospital settings
BackgroundSpore Trap is an environmental detection technology, already used in the field of allergology to monitor the presence and composition of potentially inspirable airborne micronic bioparticulate. This device is potentially suitable for environmental monitoring of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in hospital, as well as in other high-risk closed environments. The aim of the present study is to investigate the accuracy of the Spore Trap system in detecting SARS-CoV-2 in indoor bioaerosol of hospital rooms.MethodsThe Spore Trap was placed in hospital rooms hosting patients with documented SARS-CoV-2 infection (n = 36) or, as a negative control, in rooms where patients with documented negativity to a Real-Time Polymerase Chain Reaction molecular test for SARS-CoV-2 were admitted (n = 10). The monitoring of the bioaerosol was carried on for 24 h. Collected samples were analyzed by real-time polymerase chain reaction.ResultsThe estimated sensitivity of the Spore Trap device for detecting SARS-CoV-2 in an indoor environment is 69.4% (95% C.I. 54.3-84.4%), with a specificity of 100%.ConclusionThe Spore Trap technology is effective in detecting airborne SARS-CoV-2 virus with excellent specificity and high sensitivity, when compared to previous reports. The SARS-CoV-2 pandemic scenario has suggested that indoor air quality control will be a priority in future public health management and will certainly need to include an environmental bio-investigation protocol
Operational experience on the generation and control of high brightness electron bunch trains at SPARC-LAB
Sub-picosecond, high-brightness electron bunch trains are routinely produced at SPARC-LAB via the velocity
bunching technique. Such bunch trains can be used to drive multi-color Free Electron Lasers (FELs) and
plasma wake field accelerators. In this paper we present recent results at SPARC-LAB on the generation of
such beams, highlighting the key points of our scheme. We will discuss also the on-going machine upgrades
to allow driving FELs with plasma accelerated beams or with short electron pulses at an increased energy
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