291 research outputs found

    Beam Foil Interaction Studies for the Future Stripper of GANIL

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    International audienceThe GANIL 3 - cyclotron accelerator complex is tobe upgraded in 1989 by increasing the beam energy atthe stripper. In view of this modification, the effectof carbon stripper foils of various thicknesses (from50 to 250 μ\mug/cm2) on the energy spread of AI, Kr, Xeand Ta beams was measured using the aralysing sectionof the 270° spectrometer. Energies ranging from 3.2 to6.5 MeV/A (i.e. corresponding to the future energyrange) were used, and intensities of several hundredsof electrical nanoamperes were concentrated over a fewmm2 spot

    The vacuum system of the GANIL beam lines

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    http://accelconf.web.cern.ch/AccelConf/c84/papers/b36.pdfInternational audienceThe GANIL beam lines are 400 m. long and the average diameter of the pipes is 60 mm. Every fifth meter a beam diagnostic with a high desorption rate is installed. A pressure lower than 10-5 Pascal is required. The method of vacuum calculation, the reasons for the choice of our pumps (turbo molecular and cryogenic) and the results are given

    Beam transmission efficiency between injector and target in the GANIL complex

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    http://accelconf.web.cern.ch/AccelConf/c84/papers/j22.pdfInternational audienceIn order to achieve a maximum transmission efficiency, efforts have been made in three directions : beam measurements, understanding of the physical phenomenon, tuning method. The characteristics of the beam extracted from the three cyclotrons have been measured. The ensuing optical effects are analysed. The tuning of the transport-lines, depending on the characteristics of the extracted beams and the required beam properties on the target, is described

    Parameters of the eigenellipsoid for separated sector cyclotron

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    http://accelconf.web.cern.ch/AccelConf/c89/papers/g1-09.pdfInternational audienc

    Six-dimensional beam matching for axial injection into a cyclotron

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    http://accelconf.web.cern.ch/AccelConf/c89/papers/g1-01.pdfInternational audienc

    The GANIL beam lines

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    http://accelconf.web.cern.ch/AccelConf/c81/papers/ep-36.pdfInternational audienceThe general optical functions of the beam lines are described. The principle of beam lines composed of sections with separated functions was adopted. The main technological characteristics of the equipments (guiding system, buncher, stripper, beam diagnostics and pumping system) are given

    High intensity and space charge problems at GANIL

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    http://accelconf.web.cern.ch/AccelConf/c86/papers/g-04.pdfInternational audienceWe routinely accelerate up to micro-amperes of ionsat energies ranging from 25 to 95 MeV / A. Already atthese levels, space charge (S.C) problems drasticallyaffect the bunching efficiency between the ECRexternal ion-source and our Co compact injector.Moreover in the "2.5" version of GANIL we expectcurrents above 50 e\l A (Ar+6 for instance) and S.Ceffects will be of prime importance during accelerationin the injector and even in our first SSC. Wepresent our computer codes and our first results

    Ice injected into the tropopause by deep convection - Part 2: Over the Maritime Continent

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    Abstract. The amount of ice injected into the tropical tropopause layer has a strong radiative impact on climate. A companion paper (Part 1) used the amplitude of the diurnal cycle of ice water content (IWC) as an estimate of ice injection by deep convection, showed that the Maritime Continent (MariCont) region provides the largest injection to the upper troposphere (UT; 146 hPa) and to the tropopause level (TL; 100 hPa). This study focuses on the MariCont region and extends that approach to assess the processes, the areas and the diurnal amount and duration of ice injected over islands and over seas during the austral convective season. The model presented in the companion paper is again used to estimate the amount of ice injected (ΔIWC) by combining ice water content (IWC) measured twice a day by the Microwave Limb Sounder (MLS; Version 4.2) from 2004 to 2017 and precipitation (Prec) measurements from the Tropical Rainfall Measurement Mission (TRMM; Version 007) binned at high temporal resolution (1 h). The horizontal distribution of ΔIWC estimated from Prec (ΔIWCPrec) is presented at 2∘×2∘ horizontal resolution over the MariCont. ΔIWC is also evaluated by using the number of lightning events (Flash) from the TRMM-LIS instrument (Lightning Imaging Sensor, from 2004 to 2015 at 1 h and 0.25∘ × 0.25∘ resolution). ΔIWCPrec and ΔIWC estimated from Flash (ΔIWCFlash) are compared to ΔIWC estimated from the ERA5 reanalyses (ΔIWCERA5) with the vertical resolution degraded to that of MLS observations (ΔIWCERA5). Our study shows that the diurnal cycles of Prec and Flash are consistent with each other in phase over land but different over offshore and coastal areas of the MariCont. The observational ΔIWC range between ΔIWCPrec and ΔIWCFlash, interpreted as the uncertainty of our model in estimating the amount of ice injected, is smaller over land (where ΔIWCPrec and ΔIWCFlash agree to within 22 %) than over ocean (where differences are up to 71 %) in the UT and TL. The impact of the MLS vertical resolution on the estimation of ΔIWC is greater in the TL (difference between ΔIWCERA5 and 〈ΔIWCERA5〉 of 32 % to 139 %, depending on the study zone) than in the UT (difference of 9 % to 33 %). Considering all the methods, in the UT, estimates of ΔIWC span 4.2 to 10.0 mg m−3 over land and 0.4 to 4.4 mg m−3 over sea, and in the TL estimates of ΔIWC span 0.5 to 3.9 mg m−3 over land and 0.1 to 0.7 mg m−3 over sea. Finally, based on IWC from MLS and ERA5, Prec and Flash, this study highlights that (1) at both levels, ΔIWC estimated over land can be more than twice that estimated over sea and (2) small islands with high topography present the largest ΔIWC (e.g., island of Java).This research has been supported by the Cen- tre National de la Recherche Scientifique-Institut National des Sci- ences de l’Univers (CNRS-INSU), Météo-France, and the Excel- lence Initiative (Idex) of Toulouse, France (grant no. 139225)
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