ORNL, Oak Ridge, Tennessee, USA
To better understand the mechanical impact of the proton beam on the lifetime on Spallation Neutron Source (SNS*) mercury-filled, stainless steel targets, these targets are now instrumented with optical and metal strain sensors, temperature sensors, and accelerometers. The strain and temperature sensors are placed inside the target vessel, between the water shroud and mercury vessel, while the accelerators are placed outside on the target mount and on the mercury return line. We now have data from four targets. The first instrumented target used regular multimode optical sensors, while later targets have used radhard multimode sensors. We are also developing super-radhard single-mode optical strain sensors to get data further into the production cycle. In this paper, we describe the data-acquisition system, compare the measured strain to the simulated strain for the different targets, estimate the survivable radiation level for each type of sensor, and discuss the implications of the results on the lifetime of the target.
ORNL, Oak Ridge, Tennessee, USA
The Proton Power Upgrade Project is underway at the Spallation Neutron Source at Oak Ridge National Laboratory and will double the proton beam power capability from 1.4 MW to 2.8 MW to provide increased neutron intensity at the first target station and to support future operation of the second target station. This will be accomplished by increasing the beam energy to 1.3 GeV and the beam current to 38 mA (average during the macro-pulse). Installation of 28 additional superconducting cavities and their associated technical systems will provide for the energy increase. Increased beam loading throughout the accelerator will be accommodated primarily through the use of existing margin in the RF systems and the installation of 700 kW klystrons to power the new superconducting cavities. Upgrades of a few existing RF stations may also be needed. The injection and extraction regions of the accumulator ring will be upgraded, a ring to second target station tunnel stub will be constructed, and a 2 MW target will be developed for the first target station. The project anticipates attainment of Critical Decision 1 in 2017 to ratify the project conceptual design and cost range.