SNS Proton Beam Window Disposal

In order to support the disposal of the proton beam window assembly of the Spallation Neutron Source beamline to the target station, waste classification analyses are performed. The window has a limited life-time due to radiation-induced material damage. Analyses include calculation of the radionuclide inventory and shielding analyses for the transport package/container to ensure that the container is compliant with the transportation and waste management regulations. In order to automate this procedure and minimize manual work a script in Perl language was written

MCNP-model for the OAEP Thai Research Reactor

An MCNP input was prepared for the Thai Research Reactor, making extensive use of the MCNP geometry`s lattice feature that allows a flexible and easy rearrangement of the core components and the adjustment of the control elements. The geometry was checked for overdefined or undefined zones by two-dimensional plots of cuts through the core configuration with the MCNP geometry plotting capabilities, and by a three-dimensional view of the core configuration with the SABRINA code. Cross sections were defined for a hypothetical core of 67 standard fuel elements and 38 low-enriched uranium fuel elements--all filled with fresh fuel. Three test calculations were performed with the MCNP4B-code to obtain the multiplication factor for the cases with control elements fully inserted, fully withdrawn, and at a working position

Computational Benchmark Calculations Relevant to the Neutronic Design of the Spallation Neutron Source (SNS)

The Spallation Neutron Source (SNS) will provide an intense source of low-energy neutrons for experimental use. The low-energy neutrons are produced by the interaction of a high-energy (1.0 GeV) proton beam on a mercury (Hg) target and slowed down in liquid hydrogen or light water moderators. Computer codes and computational techniques are being benchmarked against relevant experimental data to validate and verify the tools being used to predict the performance of the SNS. The LAHET Code System (LCS), which includes LAHET, HTAPE ad HMCNP (a modified version of MCNP version 3b), have been applied to the analysis of experiments that were conducted in the Alternating Gradient Synchrotron (AGS) facility at Brookhaven National Laboratory (BNL). In the AGS experiments, foils of various materials were placed around a mercury-filled stainless steel cylinder, which was bombarded with protons at 1.6 GeV. Neutrons created in the mercury target, activated the foils. Activities of the relevant isotopes were accurately measured and compared with calculated predictions. Measurements at BNL were provided in part by collaborating scientists from JAERI as part of the AGS Spallation Target Experiment (ASTE) collaboration. To date, calculations have shown good agreement with measurements

The Spallation Neutron Source (SNS): Radiation Protection Aspects from Design to Commissioning

EURISOL DS/Task5/TN-06-1

Support Facility for a Graphite Target Neutrino Factory

The Target Support Facility for a Neutrino Producing Research Facility extends from the pretarget, primary beam focusing region to the end of the decay channel. Technical components include the target, beam absorber, and solenoid magnetic-field focusing system. While the ultimate goal is to target about 4 MW of proton beam in the target area., smaller values and different target materials (e.g., low Z) are considered to facilitate the first step. As detailed in this report, a carbon target was chosen with an incident primary beam power of 1.5 MW, The target is embedded in a high-field solenoid magnet of 20 T, followed by a transition section channel, where the field tapers down to 1.25 T. An iterative design process has been carried out which optimizes Monte Carlo code flux projections with realistic magnetic-field parameters. The severe radiation environment and component shielding requirements strongly influence design choices. The overall system design includes the capture and decay channel solenoids, the design parameters of which were provided by the National High Magnetic Field Laboratory. This design balances resistive and superconducting magnet contributions. Facility requirements, including shielding, remote handling, radioactive water system, etc. are based on the final design goal of 4 MW. The extent of the Target Support Facility and radiation-handling equipment includes the 50-m decay channel, where remote-handling operations are also required

ICANS XIX, 19th meeting on Collaboration of Advanced Neutron Sources ESS TARGET PERFORMANCE FOR DIFFERENT BEAM PULSES

ABSTRACT Last trends in the design of linear accelerators for high power spallation sources point to the use of ion beams of larger energies and shorter pulse lengths in order to enhance the reliability of the system. In this sense the recommendations for ESS are to increase the energy of the proton beam from 1.3GeV to 2-2.5GeV and to reduce the length of the beam pulse from 2ms to 1-1.5ms, keeping the source average power at 5MW. Different values for the repetition rate are also being discussed (16 2/3, 20, 25 Hz). ESS Bilbao is analyzing the impact of these modifications on the design of the target system. In this paper the effects of the different beam energies on the target disc thermohydraulics and the neutron performance of the source are discussed. Initial calculations were performed for a rotating target with ESS 2002 parameters. During the development of the work -that are being performed in collaboration with SNS-the decision was made to use the SNS-STS Target-Moderator-Reflector Assembly (TMRA) -slightly modified to accommodate the target design being studied for ESS-which presents a state of the art design with a cylindrical liquid para-hydrogen moderator in wing configuration aimed to enhance cold neutron production