Optical Triggering
Results
Coil D
Table
1 shows the resulting speeds for each projectile type.
Projectile 
Open Loop Speed (m/s)

Optical Speed (m/s) 
Difference (%) 
Solid 
1.12E+1 
1.07E+1 
4.67E+0 
4 mm Cored 
1.15E+1 
1.10E+1 
4.55E+0 
6 mm Cored 
1.18E+1 
1.12E+1 
5.36E+0 
Table
1. Comparison of maximum open loop speed and optical speed.
Again
we can see that the speed values are still close to the optimal speeds obtained
using the open loop triggering method.
Fig
1. Voltage, current and power curves.
Now
we can see that the current reaches a peak of about 150A and the peak internal
source loss is close to 1700W  more than double that of coil C.
Source Energy
(mJ) 
Supply Energy
(mJ) 
Projectile Energy
(mJ) 
Coilgun Efficiency
(%) 
Overall System
Efficiency (%) 
3.71E+4 
2.55E+4 
7.25E+2 
2.84E+0 
1.95E+0 
Table
2. Efficiency comparisons for solid projectile.
Now
we can see the price, in terms of efficiency, paid for the small additional speed
offered by this coil over coil C. These efficiency values are the worst of all
the coils.
