Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core an... more Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system – all with corresponding radiation shielding – was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.
ABSTRACT The promising scheme to design the intense positron source is based on using of oriented... more ABSTRACT The promising scheme to design the intense positron source is based on using of oriented crystal to generate an intense photon beam and amorphous converter for shower producing. Properties of a diamond crystal such as a high thermal conductivity ( 660 W/m.K versus 170 W/m.K for tungsten), high Debye temperature (1860K versus 379K tungsten) and the shortest lattice constant allow us to consider a thick diamond crystal (> 10mm) as a best candidate for a photon source. For axial orientation of such thick crystal only initial part of a crystal forms channeling radiation (around 0.5 mm for 10 GeV electrons); electrons emit coherent bremsstrahlung (CBS) in the remained part of a crystal. The model for estimation of radiation losses, mean photon energy and photon multiplicity in coherent bremsstrahlung processes is described in the report. The comparison of existing experimental results with developed approach has been performed. Our estimations show that for electron with energy 4.5 GeV passing through 10mm diamond target along axis, the photon multiplicity may achieve 10 photons per each electron. The efficiency of positron production by a photon beam from a thick diamond target was estimated and possibility to achieve the efficiency about one accelerated positron per each initial electron with energy ~ 10 GeV was shown.
Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core an... more Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system – all with corresponding radiation shielding – was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.
ABSTRACT The promising scheme to design the intense positron source is based on using of oriented... more ABSTRACT The promising scheme to design the intense positron source is based on using of oriented crystal to generate an intense photon beam and amorphous converter for shower producing. Properties of a diamond crystal such as a high thermal conductivity ( 660 W/m.K versus 170 W/m.K for tungsten), high Debye temperature (1860K versus 379K tungsten) and the shortest lattice constant allow us to consider a thick diamond crystal (> 10mm) as a best candidate for a photon source. For axial orientation of such thick crystal only initial part of a crystal forms channeling radiation (around 0.5 mm for 10 GeV electrons); electrons emit coherent bremsstrahlung (CBS) in the remained part of a crystal. The model for estimation of radiation losses, mean photon energy and photon multiplicity in coherent bremsstrahlung processes is described in the report. The comparison of existing experimental results with developed approach has been performed. Our estimations show that for electron with energy 4.5 GeV passing through 10mm diamond target along axis, the photon multiplicity may achieve 10 photons per each electron. The efficiency of positron production by a photon beam from a thick diamond target was estimated and possibility to achieve the efficiency about one accelerated positron per each initial electron with energy ~ 10 GeV was shown.
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Papers by Igor Tropin