108 research outputs found
A Measurement Method Based on RF Deflector for Particle Bunch Longitudinal Parameters in Linear Accelerators
No full textIn high-brightness electron linear accelerators (LINACs), the particle bunch length is measured by a radio frequency deflector (RFD). The electron bunch is deflected vertically toward a screen and its length can be obtained using vertical spot size measurements after a proper calibration, e.g., measuring the vertical bunch centroid while varying the deflecting voltage phase. The energy parameters of the bunch (the energy chirp and the energy spread) and the correlation between particle positions, divergences, and energies contribute to the bunch vertical dimension at the screen position after the RFD and so far were considered as a source of systematic errors in a bunch length measurement. The measurement theory and production model for bunch length, energy spread and chirp, as well as correlations are described. As usual in particle accelerators physics, the method is validated using numerical simulations of state-of-the-art LINACs with a reference simulation code showing a typical accuracy in the few percent levels
Very Low Emittance Muon Beam using Positron Beam on Target
No full textMuon beams are customarily obtained via K/π decays produced in proton interaction on target. In this paper we investigate the possibility to produce low emittance muon beams from electron-positron collisions at centre-of-mass energy just above the μ+μ- production threshold with maximal beam energy asymmetry, corresponding to a positron beam of about 45 GeV interacting on electrons on target. Performances on both amorphous and crystal target are presented, and the general scheme for the muon production will be given. We present the main features of this scheme with a first preliminary evaluation of the performances that could be achieved by a multi-TeV muon collider. Copyright © 2016 CC-BY-3.0 and by the respective authors
S-Band cavity BPM readout electronics for the ELI-NP gamma beam source
No full textThe Extreme Light Infrastructure – Nuclear Physics
Gamma Beam Source (ELI-NP GBS) facility will provide
an high intensity laser and a very intense gamma beam for
various experiments. The gamma beam is generated
through incoherent Compton back-scattering of a laser
light off a high brightness electron beam provided by a
720MeV warm LINAC. The electrons are organized in
compact trains with up to 32 bunches, each separated by
16ns. To optimize the laser-electron interaction and
therefore the generation of the gamma rays, one big
challenge is to precisely monitor the trajectory of each
electron bunch.
To match this requirement, at the interaction point two
S-band cavity beam position monitors will be used, and
the related readout system should perform bunch-bybunch
position measurements with sub-μm resolution.
Using 500MS/s ADC converters and dedicated data
processing, the readout system proposes an alternative
measurement concept. In this paper the architecture of the
system, the implemented signal processing and the results
of the first laboratory tests will be presented
Measurements with the ELI-NP cavity Beam Position Monitor Read-out Electronics at FLASH
No full textThe Extreme Light Infrastructure - Nuclear Physics
Gamma Beam System (ELI-NP GBS) will be installed and
commissioned starting within the next year in Magurele,
Romania. It will generate gamma beam through Compton
back-scattering of a recirculated laser and a multi-bunch
electron beam, produced by a 720 MeV LINAC. In order
to obtain bunch by bunch position measurements, four cavity
beam position monitors (cBPM) near the two interaction
points are foreseen. Extensive tests on the cBPM readout
electronics, recently developed by Instrumentation
Technologies and acquired for ELI-NP GBS, were performed
in laboratory at INFN-LNF and at FLASH in
DESY, during the user operation. In the latter case, three
cBPMs installed along the LINAC, with similar features as
the ones of ELI-NP GBS, were used as measuring devices
and signal sources for the read-out electronics under test.
We present here the measurements collected and the related
analysis, with a particular focus on the beam position
measurement resolution
Design of the diagnostic stations for the ELI-NP compton gamma source
No full textA high brightness electron Linac is being built in the
Compton Gamma Source at the ELI Nuclear Physics facility
in Romania. To achieve the design luminosity, a train of 32
bunches, 16 ns spaced, with a nominal charge of 250 pC will
collide with the laser beam in the interaction point. Electron
beam spot size is measured with optical transition radiation
(OTR) profile monitors.
Furthermore, OTR angular distribution strongly depends
on beam energy. Since OTR screens are typically placed in
several positions along the Linac to monitor beam envelope,
one may perform a distributed energy measurement along
the machine. This will be useful, for instance, during the
commissioning phase of the GBS in order to verify the correct
functionality of the C-Band accelerating structures, due
to the fact that there are OTR screens after each accelerating
module.
This paper deals with the studies of different optic configurations
to achieve the field of view, resolution and accuracy
in order to measure the energy of the beam. Several configurations
of the optical detection line will be studied with
simulation tools (e.g. Zemax)
The SFRY experience in combating the Variola vera epidemic in 1972: The significance of historical heritage for ex-Yugoslav republics in the circumstances of the COVID-19 pandemic
No full textThe outbreak of the COVID-19 (Coronavirus) pandemic in early 2020 reminded many people in the Balkans of the somewhat forgotten case of Variola vera (small pox) epidemic in the former Socialist Federal Republic of Yugoslavia (SFRY) in 1972. The example of the former Yugoslav state, which managed to conduct fast and effective vaccination of about 18 million citizens and declare the end to the epidemic within two months, has been increasingly emphasized in public. By contrast, the ex-Yugoslav republics have been fighting the (COVID-19 pandemic for the past two years, unsuccessfully for the most part. In this context, the experience of the former SFRY could be valuable and instructive for the successor states in the fight against the current pandemic. In this paper, the author attempts to provide an insight into the regulations that were in force in the SFRY before, during and after the outbreak of the Variola Vera epidemic, both at the federal level and in individual republics. Taking into consideration the historical and political circumstances and the development of new technologies from 1972 to the present time, the author aims to address the following question: is the legal framework of a state the decisive factor in combating serious infectious diseases, or may the non-legal factors prevail over legal regulation and dictate the direction of the epidemic
Analysis of the electron beam line for the test of the RFQ decelerating system for the AD antiproton decelerator
No full text
When a Neglected Tropical Disease Goes Global: Knowledge, Attitudes and Practices of Italian Physicians towards Monkeypox, Preliminary Results
No full textMonkeypox (MPX) has been regarded as a neglected tropic disease of Western and Central Africa since the early 70s. However, during May 2022, an unprecedent outbreak of MPX has involved most of European Countries, as well as North and South America. While the actual extent of this outbreak is being assessed by health authorities, we performed a pilot study on specific knowledge, attitudes, and practices (KAP) in a sample of Italian medical professionals (24–30 May 2022; 10,293 potential recipients), focusing on Occupational Physicians (OP), Public Health Professionals (PH), and General Practitioners (GP), i.e., medical professionals more likely involved in the early management of incident cases. More specifically, we inquired into their attitude on the use of variola vaccine in order to prevent MPX infection. From a total of 566 questionnaire (response rate of 5.5%), 163 participants were included in the final analyses. Knowledge status was quite unsatisfying, with substantial knowledge gaps on all aspect of MPX. In turn, analysis of risk perception suggested a substantial overlooking of MPX as a pathogen, particularly when compared to SARS-CoV-2, TB, HIV, and HBV. Overall, 58.6% of respondents were somehow favorable to implement variola vaccination in order to prevent MPX, and the main effectors of this attitude were identified in having been previously vaccinated against seasonal influenza (adjusted Odds Ratio [aOR] 6.443, 95% Confidence Interval [95%CI] 1.798–23.093), and being favorable to receive variola vaccine (aOR 21.416; 95%CI 7.290–62.914). In summary, the significant extent of knowledge gaps and the erratic risk perception, associated collectively stress the importance of appropriate information campaigns among first-line medical professionals
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