I am sure you will found this information all along the web but that will only give you a spark gap of 1 cm to 2 cm. But this my friend you will have 1 Inch of spark gap. By using your existing set up and just adding a single component It will increase the voltage.
Please note this project involve Very Lethal High Voltage and currents that can cause Immediate death if used wrongly. The sharing of this project is for education and nothing else. Use all safety equipment. This project is subjected to technically knowledgeable person only.
Step 1: How Is That!!!
What we need.
A CFL Driver Board.
2 Nos. 245 KJ 400V or equivalent Capacitor
AC Socket Plug
A Flyback Transformer.
Wires Soldering equipment.
Usr Long Wooden Or PVC pipe to Handle HV terminal.
Always discharge after power off. Capacitors can sustain high voltage for long time
the details and working principle is all available in internet.
Step 2: Why My Way )_( 1 Cm to 1 Inch
By using a single component the arc gap can be boosted from 1 cm to 1 Inch. Yes by connecting a 245KJ 400V Capacitor as shown in the figure the Out put voltage is increased. The secret. How ever prolonged use will heat up the capacitor.
Step 3: Final Show Down
Lets fire it up.
Note that the CFL driver need to be enclosed by its default enclosure before operation. Use long and Insulated Rod (PVC or wood ) to handle the HV Wire.
Be cautious . Use insulated safety Shoes and Hand Gloves.