Thermal Shock Structural Analyses of a Positron Target

Conference · Thu Jun 07 04:00:00 EDT 2001

DOI:https://doi.org/10.1109/PAC.2001.987293· OSTI ID:15007299

Stein, W; Sunwoo, A; Schultz, D C; Sheppard, J C

In the positron source of the Stanford Linear Collider (SLC), the electron beam collides with a tungsten-rhenium target. As the beam passes into the material, thermal energy is created that heats the material to several hundred degrees centigrade on a time scale of nanoseconds. The heating of the material results in thermal stresses that may be large enough to cause material failure. The analyses calculate the thermal shock pressure and stress pulses as they move throughout the material due to the rapid energy deposition. Failure of the target occurred after three years of operation with an elevated power deposition toward the end of the three years. The calculations were made with the LLNL coupled heat transfer and dynamic solid mechanics analysis codes, TOPAZ3D and DYNA3D, and the thermal energy deposition was calculated with the SLAC Electron Gamma Shower (EGS) code simulating the electron-induced cascade. Material fatigue strength, experimentally measured properties for the non-irradiated and irradiated material, as well as the calculated stress state are evaluated in assessing the cause for the target failure.

• Research Organization: Lawrence Livermore National Lab., CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 15007299
• Report Number(s): UCRL-JC-143893
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
ACCELERATORS
DEPOSITION
ELECTRON BEAMS
ELECTRONS
HEAT TRANSFER
HEATING
LAWRENCE LIVERMORE NATIONAL LABORATORY
POSITRON SOURCES
POSITRONS
STANFORD LINEAR ACCELERATOR CENTER
STANFORD LINEAR COLLIDER
TARGETS
THERMAL SHOCK
THERMAL STRESSES