The NOVA laser fusion experiment at Lawrence Livermore Laboratory in California
ID: 1430594 • Letter: T
Question
The NOVA laser fusion experiment at Lawrence Livermore Laboratory in California uses energy at the rate of 1014W (roughly 100 times the output of all the world's power plants) while its lasers are on. However, one laser pulse lasts for only 109s .Only about 0.16 % of the capacitor energy actually appears as light. Part A: How much light energy is delivered in one pulse? (This is 160V). Part B: The capacitor bank supplying this energy has a total capacitance of 0.29 F . What's the potential difference across the capacitor bank when it's fully charged?
Explanation / Answer
a) Power of laser = 10^14 W
energy by one laser = Power x time
= 10^14 J/s x 10^-9 s = 10^5 J
light energy = 0.16% of the energy
= 0.16 x 10^5 /100 = 160 J
b) energy stored in capacitor = C V^2 /2
160 = 0.29 V^2 /2
V = 33.22 volt