2,610 research outputs found
Radiation protection at CERN
This paper gives a brief overview of the general principles of radiation
protection legislation; explains radiological quantities and units, including
some basic facts about radioactivity and the biological effects of radiation;
and gives an overview of the classification of radiological areas at CERN,
radiation fields at high-energy accelerators, and the radiation monitoring
system used at CERN. A short section addresses the ALARA approach used at CERN.Comment: 22 pages, contribution to the CAS - CERN Accelerator School: Course
on High Power Hadron Machines; 24 May - 2 Jun 2011, Bilbao, Spai
Risk and Machine Protection for Stored Magnetic and Beam Energies
Risk is a fundamental consideration when designing electronic systems. For
most systems a view of risk can assist in setting design objectives, whereas
both a qualitative and quantitative understanding of risk is mandatory when
considering protection systems. This paper gives an overview of the risks due
to stored magnetic and beam energies in high-energy physics, and shows how a
risk-based approach can be used to design new systems mitigating these risks,
using a lifecycle inspired by IEC 61508. Designing new systems in high-energy
physics can be challenging as new and novel techniques are difficult to
quantify and predict. This paper shows how the same lifecycle approach can be
used in reverse to analyse existing systems, following their operation and
first experiences.Comment: 19 pages, contribution to the 2014 CAS - CERN Accelerator School:
Power Converters, Baden, Switzerland, 7-14 May 201
An inexpensive and continuous radon progeny detector for indoor air-quality monitoring
A silicon photodiode-based inexpensive detector working as a counter and spectrometer for alpha particles has been conceived, designed, constructed and analyzed in depth. Monte Carlo simulations by means of MCNPX ver. 2.7.0 code have been carried out to select the most suitable sensitive element for the intended applications. The detecting unit has been coupled to an Arduino board and tested for low-rate alpha-particle counting and spectroscopy. Results demonstrate a maximum count rate of 4000 s-1, an energy resolution corresponding to a full width at half maximum of 160 keV over the entire energy range of measured alpha (namely 4 Ă· 6.5 MeV), and the sensitive elementâs intrinsic efficiency of about 100%. Being the detector capable of distinguishing alpha energy associated to decays of radon daughters, its applications include 222Rn progeny monitoring. The air sampling system has been realized by a volumetric micro-pump forcing the air-flow through a millipore filter. By knowing the air-flow rate processed and the corresponding alpha energy spectrum measured, the concentrations of 218Po, 214Po and 210Po are determined. The potential alpha energy concentration-in-air is inferred, and effective dose evaluated. Calibration and testing measurements have been carried out by comparing the obtained results to the outputs of professional and expensive radon progeny monitor. The detector capability of âfollowingâ radon progeny concentration-in-air vs. time has been demonstrated. The device studied here can be configured as a prototype for an inexpensive radon progeny sensor to be potentially suitable for indoor air-monitoring in residential buildings, evaluating peopleâs exposures to radon and initiating corrective actions (e.g., mechanical ventilation) if necessary
The Spectral Measurement of Scattered Radiation From a Clinical Linear Accelerator Using a CZT Detector
The study of the induced radioactivity following radiotherapy with high energy X-rays from medical linear accelerator. Patient equivalent phantom made of Polymethyl methacrylate (PMMA) of 30x30x27 cm size irradiated with 15 MV X-rays from Versa HD medical linear accelerator form Elekta. Induced radioactive and ambient dose rates were measured at 0.25, 0.5 and 1 m from beam center using GR1Âź spectrometry with Cadmium Zinc Telluride (CZT) detectors having energy resolution less than 2%. Spectrum analysis was performed using MultiSpect software. The measured spectrum showed 511 keV annihilation photons possibly as a result of positron emitter of which most likely candidates are 62Cu(T1/2: 9.7 min), 64Cu (T1/2: 12.7 h ) and 57Ni (T1/2: 35.6 h) and a peak at â 1780 keV that could be attributed 28Al and 214Bi radioisotope. Ambient photon dose rates post radiotherapy treatment ranged 660 ”Gyh-1at o.5 m to 41 ”Gyh-1at 1 m. These values agree well with the results presented in the literature. Keywords: Radiotherapy; Activation Products; Gamma spectrometry; Occupational exposure; Medical Linear Accelerator. DOI: 10.7176/ALST/83-05 Publication date: November 30th 2020
Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources
[no abstract available
LEP3: a low-cost, high-luminosity Higgs factory
The discovery of a relatively light Higgs opens up the possibility of
circular e+e- Higgs factories. LEP3 is such a machine with emphasis on low
cost, since it re-uses most of the LHC infrastructure, including the tunnel,
cryogenics, and the two general-purpose LHC experiments Atlas and CMS, with
some modifications. The energy reach of LEP3 is 240GeV in the centre of mass,
close to the ZH production maximum. Alternative tunnel diameters and locations
are possible, including a Higgs factory housed in the UNK tunnel, UNK-L, and a
machine located in a new 80 km tunnel in the Geneva region, TLEP, than can
further house a very high energy pp collider. The design merits further
consideration and a detailed study should be performed, so that LEP3 can be one
more option available to the community for the next step in High Energy
Physics.Comment: presented on conference "LHC on the March", 20-22 November 2012,
IHEP, Protvino, Russi
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