Long Baseline Neutrino Experiment

Target Irradiation Damage Studies at BLIPExperiment Status

N. Simos

Help from: L. Mausner, H. Kirk, H. Ludewig, N. Souchlas, N. Mokhov, P. Hurh, J. Misek, B. Zwaska, J. Hylen

What is LBNE and to Where ?Neutrino SuperBeam from AGS

LBNE from Fermilab

Why LBNE target experiment and why BLIP?

• A series of recent BNL studies at BLIP revealed surprising results regarding some materials of interest and their ability to withstand proton-induced irradiation (i.e. graphite, CC) – First signs of “trouble” observed with LHC collimator materials

• A repeatable fluence threshold (~ 10^21 p/cm2) was identified using the BNL Linac at 200 MeV

• Fermilab NuMI target (120 GeV) performance adhered to similar fluence limitations (~ factor of 4 higher) leading to questions such: why the difference?

• Detailed studies (Fermilab/BNL) of interaction of matter with protons at different energies confirmed that the observed higher rate at BLIP is true!!

Running at BLIP

0.42 dpa in 9 weeks (graphite) 400 W/g power density

9 weeks ~ 1 LBNE year at 700 kW

Challenges in getting experiment off the ground

- MUST work in tandem with Isotope Producing Operation- incident energy of ~112.6 MeV (102 MeV on first isotope target)- Gaussian beam similar to 117 MeV operation

- Work with quantized Linac energy (139, 160.5, 181, 202)

- While degrading the beam appropriately, design target configuration to operate within desired temperature bands so to mimic actual LBNE operations (avoid runaway temperatures especially in encapsulated targets)

- Array of analyses and multitude of iterations proceeded the adoption of final configuration (MARS, MCNPX, SRIM, heat transfer and thermo-mechanical)

So, following a 9-week irradiation phase at BLIP the real work will begin to identify:

- Threshold for different graphite & CC so LBNE target lifetime can be assessed - Role of environment (vacuum, water cooled, or inert gas) in damage rate and lifetime

Targets currently in beam until the end of FY10 run

Post-irradiation study in hot labs of Bldg. 801 over the summer