Design of Velocity Map Imaging Spectrometer Equipped with a Mass Gate Discriminating Particular Photofragments

Table 1

Voltages applied to the respective electrodes and their dimensions with internal diameter Φ.

Electrode	Voltages (V)		Dimensions (mm)
	Base line value	Top line value^a	Shape	Thickness or length
Repeller, R	0^b,c	𝑉𝑅=75^b,c	racetrack, ^eΦ=20	1
	75^c,d	—^c,d
Ion Extractor, E	0^b-d	—	Racetrack, ^eΦ=10	1
Tube Entrance, T	−340^b-d	—	Racetrack, ^eΦ=15	1
Drift Tube	−340^b-d	—	cylinder, Φ=40,Φ=130	340 (length)
Mass Gate, M	−340^b,d	𝑉𝑀=100^b,d	cylinder, Φ=44	10 (length)
	−340^c	—^c
Retarding Grid, ^fG2	80^b,d	—^b,d	circle, Φ=44	1
	0^c	—^c

^aVoltage at the top line of the pulse waveform. Not applicable in the case of a DC operation.
^bFor the PEX mode.
^cFor the control experiments.
^dFor the PEPICO mode.
^eAxes of 50 × 66,
^fSecond disk electrode of the ion reflector G.