Tomoyuki Sanuki, Daisuke Okamoto, Yosuke Honda, Toshiaki Tauchi TB&SGC meeting.

Tomoyuki Sanuki, Daisuke Okamoto,Yosuke Honda, Toshiaki Tauchi

TB&SGC meeting

contents

IntroductionPrincipleDesign(prototype)Performance(prototype)

PurposeTest placeTime schedule

Conclusion

introduction

We have studied tilt monitor as the new type of the cavity beam monitor

θ

Measure θ with high precision

Beam line Tilted beam

Tilt monitor is useful because of its “single cavity measurement”

I proposed “the tilt monitor at IP” 9th June, in project meeting

Of course there are some issues to solve . detailed location, dynamic range ~ 200uradI will continue the study of the tilt monitor.

We need the real test with actual monitor “prototype”

Principle-Resonant mode Tilt monitor uses monopole mode.

Monopole mode is perpendicular to nominal beam axis

excitedno excited

Nominal beam Tilted beam

Ｕ (excited energy) ∝ θ2 (including time transit factor)

E-field

H-field

Beam pipe

Cavity weak strong

How to extract the signal

The magnetic field of monopole mode is extracted through slit,and transmitted by TE mode.

TE mode signal is couple to the coaxial antenna.

V(extracted signal) ∝ θ

E-field

H-field

waveguideantenna

TE modeslit

Design Sensor cavity

width

length

width[m

m]

length[m

m]1-degree

Excited energy[J]

Width : length=1:1.1　 is almost best set

The resonant frequency

2.856GHz

We designed Sensor cavity as the excited energy was larger.

77.4mm

70.4mm

Design – waveguide+ antenna

TE signal antenna

Reflection amplitude

Reflection amplitude

At 2.856Ghz Reflection amplitude is zero

We designed waveguide + antenna as the TE mode signal was coupled antenna

Total structure

frequency 2.856GHz

τ(power) 150nsec

τ(amplitude) 300nsec

Qloaded 3470

Β(Qwall/Qext) 3.45

Sensor cavity size

Width 77.4mm

length 70.4mm

height 30mm

pipe radius 10mm

Performance

Evaluating the extracted power

Thermal noise

The limitation : about 35nrad

Orbit angle[urad]

Determined by temperature(T) and bandwidth(Δf)

Room temperature 300[K]Bandwidth ～ 3MHz

PTN =1.24×10-14 [W]

Output power[W]∝ θ ２

PTN = KBTΔfThermal noise

Short Summary

Prototype of the tilt monitor has the expected sensitivity 35nrad

I think I will use as complemental device of the IP-BPM

Of course, there is some issue to solve, the detailed location ,dynamic range

Tilt monitor is the new technique of cavity beam monitor.We have to confirm the basic property.

First experiment using prototype model

the sensitivity 35nrad is equal to about 2.5nm for distance 7-8cm

About Experiment

purpose

We will confirm the property of the extracted signal

which the amplitude depends on only beam tilt V0 ∝ θ

In first test, we will measure the amplitude of signal for some micro radians with using attenuator for calibration.

1.2e+4

8e+3

4e+3

0-4 -2 2 40

V0[volt]

θ[urad]

3e-9

2e-9

1e-9

-1e-9

-2e-9

-3e-9

0

0 4e-7 8e-7 1.2e-6

Time [s]

V[volt]

2τV0

Test place

We will use the space reserved for IP BPM test area

We think we can steer the vertical beam tilt with steering magnet ZV11X and ZV10X

If we can take some occupancy shifts

Not occupancy shift

We will measure the signal for mechanical moving as there will be no influence for another shift.

Time schedule 2009

design drawing Production Cold test

6 7 8 9 10 11 12 1 ~

2010

1st test

1st test

Future

We will test the basic relation of amplitude of the signal and beam orbit for some urad beam tilt.

I would like to do this first test in November ~December.

There is a Personal reason for writing master thesis..

One shift per week times 4 ：　 thus 4shifts

Manpower availableDaisuke Okamoto, Tomoyuki Sanuki from Tohoku Univ.Yosuke Honda at KEK are main workers.OthersToshiaki TauchiToshikazu Takatomi (engineer @ KEK)High energy physics group in Tohoku Univ.(Hitoshi Yamamoto et al.)

Expected KEK workloads

Work for installing : cabling, vacuum chamber, alignment

Beam parameter

Single bunch run

Charge : a harf of 1.6 nC or a third of 1.6nC

Conclusion

We would like to confirm the property of the extracted signalIn the prototype of tilt monitor.

I’m preparing the engineering drawing with contacting Takatomi-san

The prototype will be preparing until 10 or 11.

After cold test, we would like to install at the test place and test

As the future we will aim the sensitivity 35nrad with prototype.