• J. E. Spencer
  

We consider optimization of the generalized luminosity per unit cost of a linear collider in this ES&H era. Examples running over the length of the LC, starting at the source and ending at the dump, suggest that both costs (capital and operating) and environmental issues can be improved in a compatible way. Thus, a RoHS by any other name (WEES or OSHA) need not present thorny problems requiring unexpected R&D but a push to leverage many recent advances that might otherwise be overlooked or avoided. The physics is interesting and the true amortized cost may be seriously underestimated by ignoring such issues. For example, the entire, interior surface of a laser driven RF gun involves interesting materials science where the space requires continuous UHV to sustain stable, acceptable quantum efficiency as well as avoid RF breakdown damage in an environment that is also subject to radiation damage. All of these can seriously reduce a gun's output and LCs luminosity. Intelligent design of rad-hard systems can approach the ideal of bug-proof software that needn't produce overly slow or ponderous systems while providing opportunities to innovate that justify the costs.

• J. E. Spencer
  
• S. D. Anderson, Z. R. Wolf
  SLAC, Menlo Park, California
• M. Boussoufi
  UCD/MNRC, McClellan, California
• G. Gallagher, D. E. Pellet
  UCD, Davis, California
• J. T. Volk
  Fermilab, Batavia, Illinois

Many materials and electronics need to be tested for the radiation environment expected at linear colliders (LC) to improve reliability and longevity since both accelerator and detectors will be subjected to large fluences of hadrons, leptons and gammas. Examples include NdFeB magnets, considered for the damping rings, injection and extraction lines and final focus, electronic and electro-optic devices to be utilized in detector readout, accelerator controls and the CCDs required for the vertex detector, as well as high and low temperature superconducting materials (LTSMs) because some magnets will be superconducting. Our first measurements of fast neutron, stepped doses at the UC Davis McClellan Nuclear Reactor Center (UCD MNRC) were presented for NdFeB materials at EPAC04 where the damage appeared proportional to the distances between the effective operating point and Hc. We have extended those doses, included other manufacturer's samples and measured induced radioactivities. We have also added L and HTSMs as well as a variety of relevant semiconductor and electro-optic materials including PBG fiber that we studied previously only with gamma rays.

• I. Baek
  
• R. Remec
  ORNL, Oak Ridge, Tennessee
• R. M. Ronningen, X. Wu, A. Zeller
  NSCL, East Lansing, Michigan

In supporting pre-conceptual research and development of the Rare-Isotope Accelerator facility or similar next-generation exotic beam facilities, one critical focus area is to estimate the level of activation and radiation in the linear accelerator second stripping region and to determine if remote handling is necessary in this area. A basic geometric layout of the second stripping region having beamline magnets, beam pipes and boxes, a stripper foil, beam slits, and surrounding concrete shielding was constructed for Monte Carlo simulations. Beam characteristics were provided within the stripping region based on this layout. Radiation fields, radioactive inventories, levels of activation, heat loads on surrounding components, and prompt and delayed radiation dose rates were simulated using Monte-Carlo radiation transport code PHITS. Preliminary results from simulations using a simplified geometry show that remote handling of foils and slits will be necessary. Simulations using a realistic geometry are underway and the results will be presented.