5,491 research outputs found
Strawberry breeding for disease resistance in Dresden
Verticillium resistance is one of the most important breeding goals in strawberry resistance
breeding at Dresden-Pillnitz. Resistance evaluation of cultivars, advanced selections and
seedlings is realized under natural conditions at a provocation field and by artificial
inoculation in the greenhouse. Introgression of Fragaria chiloensis L. (Miller) into Fragaria
Ă—ananassa Duch. resulted in highly tolerant breeding selections. After back-crossing with
cultivars of F. Ă—ananassa first genotypes were selected which can be evaluated in
experimental cultivar trials at different locations in Germany
Status of Studies for a Muon Cooling Experiment
A possible layout for a cooling experiment is being studied to demonstrate the feasibility of the CERN reference scenario for a muon cooling channel of a future neutrino factory. Tracking of muons in 3D magnetic and electric fields was performed with the aim of validating the set-up, i.e. the possibility of extrapolating to the final reference channel. Simulation results are shown together with the cavity/solenoid engineering design. The direction of the work in progress is indicated and discussed
Muon Front-End without Cooling
In this note a muon front-end without cooling is presented. The muons are captured, ro-tated and accelerated to the energy needed for injection into the first muon recirculator. The cavity parameters are consistent with those used for the CERN reference scenario [1]. The number of muons obtained per year is roughly one order of magnitude less than the one obtained with the cooling channel. Therefore such a scheme could be a first step to a neutrino factory keeping the option of later upgrade
Tuning Knobs for the PS-SPS Transfer Line
Transverse emittance preservation will be an important issue for the LHC injector chain. Minimisation of the blow-up at injection by tuning independently the Twiss parameters (a,b), the dispersion D and the dispersion derivative D' is therefore mandatory. The optics of the transfer line between the PS and SPS machines was modelled and matched using the program package MAD. Tuning knobs were developed using a singular value decomposition (SVD) algorithm. Coupled to the measurement of the Twiss parameters at a given point downstream of the correction elements they provide a fast correction algorithm for the betatron mismatch
Design of a high-intensity RFQ for a possible LHC laser ion source
We have designed a 100 MHz RFQ to accelerate Pb25+ ions from 9.6 keV/u to 250 keV/u for the LHC ion program. We assume an input beam from a laser ion source with a total beam current of 90 mA, out of which 9 mA is Pb25+. The main challenge of the design is to match the tight longitudinal acceptance of the downstream Interdigital H structure while dealing with a high intensity beam composed of a variety of charge states. In this paper, we present a baseline setup optimized for nominal conditions, and show the sensitivity of the RFQ performance to varying input beam characteristics and rf parameters. Further studies will cover the compatibility of this design with an upgraded ECR source under investigation at CERN
Beam Dynamics Study of a Cooling Experiment based on the 88 MHz CERN Cooling Channel
This note presents a beam dynamics analysis of a possible muon cooling experiment based on 88 MHz cavities. The proposed set-up is a subsection of the cooling channel in the CERN reference scheme for a neutrino factory. We present two different set-ups using 8 and 4 cavities. For each of these set-ups we have carried out a beam dynamics study based on engineering designs for the cavities and solenoids. The study includes a parameter scan which allows to evaluate the performance of the systems for various input beam parameters and settings
Finding the optimum activation energy in DNA breathing dynamics: A Simulated Annealing approach
We demonstrate how the stochastic global optimization scheme of Simulated
Annealing can be used to evaluate optimum parameters in the problem of DNA
breathing dynamics. The breathing dynamics is followed in accordance with the
stochastic Gillespie scheme with the denaturation zones in double stranded DNA
studied as a single molecule time series. Simulated Annealing is used to find
the optimum value of the activation energy for which the equilibrium bubble
size distribution matches with a given value. It is demonstrated that the
method overcomes even large noise in the input surrogate data.Comment: 9 pages, 4 figures, iop article package include
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