Back of the envelope calculation for e+/e- ratio

run#

T1

T2

Sweep Magnet

logic

HV-D2L

HV-D1R

Reprate

start

stop

Int Rate

event number

pulses

3735

in

in

out

(DL & GunTrig) & (DR & GunTrig)

1150V

1150V

300-301

15:54:24

16:11:06 (1002 s)

9.0200 events/s

9045

301462

3736

in

out

out

(DL & GunTrig) & (DR & GunTrig)

1150V

1150V

300-301

16:12:15

16:27:07 (892 s)

4.1736 events/s

3752

268289

Run 3735 positron charge

positron rates is 0.26 Hz.

Run times is 1002.

The total positron in this run is 260.

The current of the positron beam is: [math]260 \times 1.6 \times 10^{-19}=4.2 \times 10^{-17} [/math] C.

Run 3735 electron charge

The electron peak current is around 100 mA.

The pulse width is: 300 ns.

Then current in a single pulse is: 300 ns * 100 mA = 30 nC.

The total pulses in this run are: 301462

Then the total charge is this run: 30 nC * 300,000 = 9 mC.

e+ to e- ratio

e+ / e-= [math]\frac{4.2 \times 10^{-17}~C} {9~mC}[/math]

[math]= \frac {4.2 \times 10^{-17}} {9 \times 10^{-3}}[/math]

[math] = 0.5 \times 10^{-14} [/math]

[math]= 5 \times 10^{-14} [/math]