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MATERIAL IRRADIATION STUDIES FOR HIGH-INTENSITY PROTON BEAM TARGETS AND COLLIMATORS BNL AGS/BLIP/Hot Cell FACILITY. Nicholas Simos, BNL. SCOPE ASSESS the effects of proton irradiation on material properties that are key in the design and operation of high power targets and collimators
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MATERIAL IRRADIATION STUDIES FOR HIGH-INTENSITY PROTON BEAM TARGETS AND COLLIMATORSBNL AGS/BLIP/Hot Cell FACILITY Nicholas Simos, BNL N. Simos - LARP (02-03-05)
SCOPE • ASSESS the effects of proton irradiation on material properties that are key in the design and operation of high power targets and collimators • Experiment is Focused on: • Effects of Protons on Graphite • Is proton Irradiation any different than Neutron Irradiation? • Are properties of Graphite such as conductivity change as drastically as with neutrons? • What are the effects of the surrounding ambient? (air, vacuum, inert gases) • Is there an “optimal” operational temperature range? • Is Carbon-Carbon the alternative to Graphite? • How about these new “smart” materials? (Gum metal, AlBemet, etc.) N. Simos - LARP (02-03-05)
WHY SHOULD WE BE WORRIED? • REACTOR Experience on Graphites and CC composites under neutron irradiation paints a bleak picture: • The key property that we rely on in the collimator (diffusivity and/or conductivity) to transport the beam deposited load can diminish dramatically • Workable scenarios that so far dictate the design already operate close to the limits with unaffected properties Observe in the following Figures the dramatic effects of irradiation on these materials: N. Simos - LARP (02-03-05)
How Do We Make Sure the Collimator Design is based on Best Possible Knowledge of Material Behavior? • Either the design adopts the worst-case-scenario based on existing results from neutron irradiation (i.e. reduce diffusivity by a factor of 8 or 9) in which case it will not make it, or • Experiment with the material under conditions that are close to what the real thing will experience (no arm-waving can work in this case) ARE WE DOING ANYTHING ABOUT IT? The answer is YES, but there is need for a “PUSH” to get us to the next level N. Simos - LARP (02-03-05)
TEST-1: SHOCK Test Using 24 CeV Protons Graphite vs. Carbon-Carbon N. Simos - LARP (02-03-05)
ATJ Graphite vs. Carbon-Carbon Composite 1sr Indicator: CC is the way to go if we care to absorb shock. Do things hold true after irradiation? N. Simos - LARP (02-03-05)
Previous Studies Focused on Super-Invar N. Simos - LARP (02-03-05)
Some Alloys Change Drastically and some Don’t N. Simos - LARP (02-03-05)
Irradiation Studies & POST-Irradiation Studies CURRENT MATERIAL STUDY MATRIX • Carbon-Carbon Composite • Toyota “Gum Metal” • Graphite (IG-43) • AlBeMet • Beryllium • Ti Alloy (6Al-4V) • Vascomax • Nickel-Plated Alum. N. Simos - LARP (02-03-05)
Irradiation Studies & POST-Irradiation Studies On Going in HOT CELL Facility Measuring Irradiation Effects on Material Thermal Expansion, Mechanical properties, thermal conductivity/diffusivity and Thermal Shock N. Simos - LARP (02-03-05)
Irradiation Studies & POST-Irradiation Studies Material Irradiation – Completed in April 2004 N. Simos - LARP (02-03-05)
Temp. % elongation 23 o C 0% 200 o C -0.023% 400o C -0.028% 600o C -0.020% 800o C 0% 1000o C 0.040% 1200o C 0.084% 1600o C 0.190% 2000o C 0.310% 2300o C 0.405% 3-D Fine-Weaved Carbon-Carbon Composite Under Study N. Simos - LARP (02-03-05)
Gum Metal (Toyota Ti alloy) N. Simos - LARP (02-03-05)
WHERE ARE WE AND WHAT IS NEEDED TO COMPLETE? • Most Mechanical Testing Completed (currently evaluating the IG-Graphite to be followed by Carbon-Carbon – All other materials done – Data are still in raw form) • During next LARP Video I will have a complete presentation • Graphite and CC composite thermal expansion/swelling are in progress: • Completed evaluation at 300 deg. C and in air • Next phase will be at higher temperatures (gradually creeping to 1100 C) and with (a) vacuum and (b) helium) • Preliminary tests of CC up to 600 C indicated that there is either sublimation or oxidation taking place when in air. • Workable scenarios that so far dictate the design already operate close to the limits with unaffected properties N. Simos - LARP (02-03-05)
WHAT IS NEEDED TO COMPLETE? • Scrutinize Graphite & CC Composite at Higher Temperatures and different environments (biggest problem is the unavailability of funds to use the Hot Cell Facility, it cost me ~ $850/day to operate in one cell) • Following thermal expansion/swelling changes in Graphite & CC perform the most important evaluation: DIFFUSIVITY/CONDUCTIVITY CHANGES IN THESE MATERIALS • Availability of funds is the sticking problem again • enhance the apparatus to allow for these measurements in the hot cell • Pay for the extended use of the hot cell facility • OFF-BEAM Shock Resilience of Graphite/CC • High Power Laser System ready to go • need of funding for a post-doc who is joining me in March N. Simos - LARP (02-03-05)