fd jitter tolerance study min-huey wang. 2 introduction investigate three bds designs l* 4.5 m, l*...

FD Jitter Tolerance Study

Min-Huey Wang

2

Introduction

• Investigate three BDS designs L* 4.5 m, L* 4.0 m and L* 3.5 m.

• Using 500 GeV baseline parameters from TDR Table 2.1 and Table 8.2.

• Using elegant + GUINEA-PIG to simulate LUMI loss criteria for QF1/SF1/OC1 and QD0/SD0/OC0 offset with IP fast-feedback compensating.

• Three locations of FFB thin length kickers are simulated (beam direction).

- At middle of QF1 and QD0- Before SD0- After QD0 (L* 4.0 m)

• Track 80k macro particles (e- & e+ side) from QF1 -> IP with RMS vibration in horizontal and vertical planes.

3

IP FFB kicker position

QD0QF1SD0SF1

Simulate the kicker effect at three locations

IP

4

• Track 80K macro particles (e- & e+ side) from QF1 -> IP with RMS SF1/QF1 and SD0/QD0 vibration in horizontal and vertical planes.

• Results show mean and range of luminosities from 100 consecutive pulses.

L* 3.5 m waist (FFB kickers 1.5 m upstream SD0)

0 100 200 300 400 500 60040

50

60

70

80

90

100

RMS SF1/QF1 + SD0/QD0 x & y vibration /nm

% N

omin

al L

umin

osit

y

L* 3.5 m

5



L* 3.5 m waist (FFB kickers right before SD0)

0 100 200 300 400 500 60040

50

60

70

80

90

100


% N

omin

al L

umin

osit

y

L* 3.5 m

6




0 100 200 300 400 500 60040

50

60

70

80

90

100


% N

omin

al L

umin

osit

y

L* 4.0 m

7




0 100 200 300 400 500 60040

50

60

70

80

90

100


% N

omin

al L

umin

osit

y

L* 4.0 m

8



L* 4.0 m waist (FFB kickers after QD0)

0 100 200 300 400 500 60040

50

60

70

80

90

100


% N

omin

al L

umin

osit

y

L* 4.0 m

9




0 100 200 300 400 500 60040

50

60

70

80

90

100


% N

omin

al L

umin

osit

y

L* 4.5 m

10




100 200 300 400 500 600

50

60

70

80

90

100


% N

omin

al L

umin

osit

y

L* 4.5 m

11

Summary

• The FFB kickers close to or after QD0 have less negative impact on beam luminosity

100 200 300 400 50040

50

60

70

80

90

100


% N

omin

al L

umin

osit

y

L* 3.5 mL* 4.5 mL* 4.5 m corL* 3.5 m corL* 4.0 mL* 4.0 m corL* 4.0 m cor1

12

Jitter tolerance of 2% luminosity loss

L* 3.5 4.0 4.5

Between QF1 QD0 < 25 21 100

Before QD0 < 25 42.6 <25

After QD0 --- 25 ---

13

Summary

• The luminosity of idea beam w/o waist shift is 1.36/1.51/1.45E34 cm-2 s-1 (L*4.5/4.0/3.5) from GUINEA-PIG. It is close to geometric luminosity of 1.47E34 cm-2 s-1 in TDR.

• Scanning the y waist the best luminosity is 1.69/1.70/1.58E34 cm-2 s-1 (L*4.5/4.0/3.5) at y waist 405/300/240 mm.

• The jitter tolerances of three BDS designs are similar.

• The effect of distance of FFB kickers from SD0 start to take effects with incresing RMS jitter.

fd jitter tolerance study min-huey wang. 2 introduction investigate three bds designs l* 4.5 m, l*...

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