Transcript Current pulse in the tungsten wire

Results
Isostress* lines for tungsten target and wire
(operating at 2000 K)
Beam power [MW]
LS-DYNA
Target: repetition rate = 50 Hz;
beam energy = 6 GeV;
beam radius = target radius;
beam offset = 0.5*target radius;
3 x 2 ns long bunches;
pulse length = 20 s (2cm x 17cm),
25 s (3cm x 20cm);
energy deposition = MARS
3 cm diameter target
2 cm diameter target
Wire: 0.5 mm diameter, 3 cm long;
800 ns long pulse, exponential rise,
100 ns rise time
* - Von Mises stress
Peak current [kA]
Wire test results:
Number of pulses to failure [x106]
new -> 10.0(nb) [Max temp = 1900K]
2.0(nb) [Max temp = 1800K]
0.00001
Max temp = 2200 K
1.0
Max temp = 1900 K
1.6
Max temp = 1900 K
Max temp = 2050 K
4.2(nb) + 9.0(nb)
Max temp = 1900 K
Max temp = 2000 K
Beam power [MW]
3.4(nb)
+
3 cm diameter
target
2 cm diameter
target
Peak current [kA]
(nb) = not broken
Stress as a function of temperature jump in the
tungsten target and wire (operating at 2000 K)
Peak von Mises stress [MPa]
Target: 3cm x 20cm; repetition rate = 50 Hz;
beam energy = 6 GeV; 3 x 2 ns long bunches; pulse length = 25 s;
beam radius = target radius; beam offset = target radius/2;
energy deposition = MARS
Wire
Target
LS-DYNA
Wire: 0.5 mm diameter, 3 cm long;
800 ns long pulse, exponential rise,
100 ns rise time
Temperature rise (peak value) [K]
The current needed in a test with thicker tungsten wire in
order to have the same peak stress as in a real target
2 cm diameter target
3 cm diameter target
Results
LS-DYNA
Target: repetition rate = 50 Hz; beam energy = 6 GeV;
beam radius = target radius; beam offset = 0.5*target radius;
3 x 2 ns long bunches; pulse length = 20 s (2cm x 17cm),
25 s (3cm x 20cm); energy deposition = MARS
Beam power [MW]
0.75 mm diameter wire
1 mm diameter wire
1.25 mm diameter wire
Wire: 3 cm long; 800 ns long pulse,
exponential rise, 100 ns rise time.
Peak current [kA]