Measure an electric charge of an electron and mass rate, and understand
Lorentz force when a charged particle have motion under geomagnetic
field. 

e/m apparatus(1)
e/m tube : to insert He gas, 150mm diam,
Helmholtz coil: 300dia, wire 1mm diam, N=130,
black body box : Acrylic, 335 x 255 x 335 mm
Ruler(1) : Transparent acrylic

Lead wire(6) 

Power Supply(1) : SG-6134D 

Power supply for e/m apparatus 

Size : 360 x 340 x 150 mm 

Weigh : 5Kg 

DC Output : 0~300V, 0~12V dual Power, Current 0~3A 

AC Output : 6.3V heating Voltage
Volt, Current meter : Digital