• M.A. Plum, A. Abdou, P.D. Ferguson, P.J. Geoghegan, L.L. Jacobs, J.G. Janney, S.M. McTeer, I.I. Popova, A.P. Zhukov
  ORNL, Oak Ridge, Tennessee

Funding: SNS is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC05-00OR22725

As the SNS beam power is increased, the collimator systems are becoming correspondingly more important. The High Energy Beam Transport (HEBT) transverse collimators are now routinely used during neutron production. We are in the process of redesigning the HEBT momentum collimation system due to problems with gas production from radiolysis. The Ring collimators are designed for two-stage operation but to date they are mainly used in one-stage mode. In this paper we will discuss the status, the operational performance, and upgrades to the collimation systems.

• A.P. Zhukov
  ORNL, Oak Ridge, Tennessee
• I. Nesterenko
  BINP SB RAS, Novosibirsk

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

Conversion of BLM readings into number of lost particles is a challenging task. Any insertion device is a good mean to obtain a localized loss and obtain such conversion factor with direct measurement. Such a measurement serves as a good benchmark for Monte-Carlo simulation of radiation transport. We used wire scanners and scraper induced losses to perform analysis of BLM response to local loss. The paper also provides a technique to measure 0.1% of full beam charge being intercepted by scraper during 650kW production run extracting the useful signal from high noise (20 times higher than signal) environment

• A.P. Zhukov, S. Assadi, R. Dickson, J. Pogge
  ORNL, Oak Ridge, Tennessee
• V. Gaidash
  RAS/INR, Moscow

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

SNS is a high intensity hadron beam facility; so the Beam Loss Monitor (BLM) system is a crucial part of Machine Protection System and an important tool for beam tuning. The paper presents the current status of installed detectors and experimental data obtained during SNS operations. We compare several different types of BLMs and show advantages and disadvantages of each type. The electronic parts obsolescence became a real issue since the original electronics was designed about 10 years ago. The first test of our next generation BLM system is expected to be done by summer 2009. The new system will contribute to significant noise reduction and will follow a modular concept of Smart Device to achieve a higher degree of reliability and maintainability.