1 feedback on nanosecond timescales (font): philip burrows neven blaskovic, douglas bett*, talitha...
TRANSCRIPT
![Page 1: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/1.jpg)
1
Feedback On Nanosecond Timescales (FONT):
Philip Burrows
Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry
John Adams Institute, Oxford University
* Now at CERN
IP Feedback
![Page 2: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/2.jpg)
2
Outline
• Reminder of CLIC IP FB prototype
• ATF2 IP FB concept
• Results of recent beam runs
• Summary + conclusions
![Page 3: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/3.jpg)
3
IP beam feedback concept
Last line of defence against relative beam misalignment
Measure vertical position of outgoing beam and hence beam-beam kick angle
Use fast amplifier and kicker to correct vertical position of beam incoming to IR
FONT – Feedback On Nanosecond Timescales
![Page 4: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/4.jpg)
CLIC Final Doublet Region
4
![Page 5: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/5.jpg)
CLIC Final Doublet Region
5
![Page 6: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/6.jpg)
CLIC Final Doublet Region
6
![Page 7: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/7.jpg)
7
CLIC IP FB performance
Single random seed of GM C
Resta Lopez
![Page 8: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/8.jpg)
8
For noisy sites:
CLIC IP FB performance
factor 2 - 3 improvement
![Page 9: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/9.jpg)
FONT5 intra-train FBs at ATF2
ATF2 extraction line
99
![Page 10: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/10.jpg)
FONT5 operation modes at ATF2
10
Aim to stabilise beam in IP region using 2-bunch spill:
1. Upstream FB: monitor beam at IP
2. Feed-forward from upstream BPMs IP kicker
3. Local IP FB using IPBPM signal and IP kicker10
![Page 11: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/11.jpg)
11
IP kicker IPBPMs
FONT digital
FB
IPBPMelectronics
FONTamplifier
e-
ATF2 IP FB loop scheme
Eventual goal is to stabilise the small ATF2 beam (design 37nm)at the nanometer level
![Page 12: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/12.jpg)
12
IP kicker
Designed by Oxford
Fabricationarrangedby KEK
Installed May 2012
![Page 13: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/13.jpg)
13
Nanometer beam FB at ATF2 IP• Much harder than IPFB at ILC or CLIC!
• Only 1 beam must measure beam position directly
• nm-level stabilisation requires nm-level position meas.
Cavity BPMs (rather than striplines)
• Cavities slower, signal processing more involved
• Cavities required to resolve 2 bunches within << 300ns with high
spatial resolution
Low-Q cavities
Low-latency, high-resolution signal processor
![Page 14: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/14.jpg)
14
IP kicker IPBPMs
FONT digital
FB
IPBPMelectronics
FONTamplifier
e-
Preparatory tests June 2013
Existing IPBPMs
Honda low-latency electronics
![Page 15: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/15.jpg)
15
New kicker
A B
![Page 16: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/16.jpg)
Interaction Point FONT System
Analogue Front-end
BPM processor
FPGA-based digital processor
Kicker drive amplifier
Strip-line kicker
Beam
Cavity BPM
16
Latency ~ 160ns
![Page 17: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/17.jpg)
2013 beam stabilisation results
1. Upstream FB: beam stabilised at IP to
~ 300 nm
2. Feed-forward: beam stabilised at IP to
~ 106 nm
3. IP FB: beam stabilised at IP to ~ 93 nm
17
![Page 18: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/18.jpg)
IP Feedback Results
FB Off Jitter: 170 ± 10 nmFB On Jitter: 93 ± 4 nm
FB Off Correlation: 81%
18
![Page 19: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/19.jpg)
IP Feedback Results
FB Off Jitter: 170 ± 10 nmFB On Jitter: 93 ± 4 nm
FB Off Correlation: 81%
FB On Correlation: -16%19
![Page 20: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/20.jpg)
In vacuum IP-BPMs and piezo movers
BPM A&B
BPM C
Piezo Movers(PI)
Piezo Movers(Cedrat)
BPMs– Bolted aluminum plates, no
brazing because of In-vacuum.
– BPM A&B bolted together.– BPM C is independent.
Piezo mover– BPM units are mounted on
the base with three piezo movers.
– Dynamic range of each mover is +/- 150 um.
IP
Slide from Terunuma
Initial alignment need to be better than this.
Installed summer 2013
![Page 21: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/21.jpg)
21
IP kicker IPBPMs
FONT digital
FB
IPBPMelectronics
FONTamplifier
e-
Tests started November 2013
New IP chamber installed Summer 2013
Honda electronics
![Page 22: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/22.jpg)
22
2014 beam tests
• IP chamber was removed, re-worked and re-installed
• New IPBPMs were fabricated
• Commissioning began in October 2014
• Some preliminary results to show today:
• Longitudinal IP position set at each IPBPM in turn:
position calibration + beam jitter studies
• High-beta (‘pencil-beam’) optics: BPM resolution
• Beam waist IP feedback
![Page 23: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/23.jpg)
23
Nominal optics
![Page 24: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/24.jpg)
24
BPM calibration constant vs. attenuation
![Page 25: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/25.jpg)
25
BPM calibration constant vs. attenuation
Indicative ofsaturation ofelectronics
![Page 26: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/26.jpg)
26
Beam jitter (at waist) vs. attenuation
![Page 27: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/27.jpg)
27
Beam jitter (at waist) vs. attenuation
Consistent with true beam jitter ~ 300nm (beam not tuned after DR extr. kicker issue)
![Page 28: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/28.jpg)
28
High-beta (pencil beam) optics
![Page 29: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/29.jpg)
29
Beam jitter vs. attenuation
![Page 30: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/30.jpg)
30
Beam jitter vs. attenuation
Consistent with true beam jitter ~ 500nm (pencil beam large)
![Page 31: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/31.jpg)
31
Resolution vs. attenuation
![Page 32: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/32.jpg)
32
Resolution vs. attenuation
Resolution appearsto be 200-300nm!(NB: C >> A, B)
![Page 33: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/33.jpg)
33
Nominal optics: IPFB @ IPBPM B
![Page 34: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/34.jpg)
34
Best IPFB results
Bunch 1: not corrected,jitter ~ 400nm
Bunch 2: corrected,jitter ~ 67nm Corrected jitter 67nm
<< apparent resolution!
![Page 35: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/35.jpg)
35
Best IPFB results
![Page 36: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/36.jpg)
36
Scan of bunch 2 position using IPK
Apply constant kicksto bunch 2 to move itsvertical position in theIPBPM
measurement closer to ‘zero’ should havebetter resolution
Then turn on IPFB …
![Page 37: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/37.jpg)
37
IPFB performance vs. bunch 2 posn.
IPFB off
IPFB on
![Page 38: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/38.jpg)
38
IPFB performance vs. bunch 2 posn.
IPFB off
IPFB on
![Page 39: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/39.jpg)
39
Best standard jitter measurement
66nm(single) 49nm(avg.)
![Page 40: 1 Feedback On Nanosecond Timescales (FONT): Philip Burrows Neven Blaskovic, Douglas Bett*, Talitha Bromwich, Glenn Christian, Michael Davis, Colin Perry](https://reader033.vdocument.in/reader033/viewer/2022051619/56649e035503460f94aee07a/html5/thumbnails/40.jpg)
40
Summary + conclusions• Started commissioning of new ATF2 IP chamber/IPBPMs
• Lot of preliminary results; many mysteries to understand
• IPFB works well: corrects beam jitter to 67nm
• We believe this performance is resolution-limited
• Suspect IPBPM B resolution is currently < 50nm
• Contradiction between direct resolution measurements (200-
300nm) and IPFB performance (67nm)
• We suspect a problem with IPBPM C, which degrades the 3-BPM
resolution measurement
• BPM performance depends strongly on beam position ~ 0