3243 Fri 23 Nov Summary

3243 Fri 23 Nov Summary• INJ-BPM-01: took 1 shot of data, just a reference to compare with previous recent shifts

– Did not see a strong dominant 100 kHz signal, but it might be present in 0-200 kHz frequency content• INJ-BPM-02: vs steering, solenoid, buncher

– 300 kHz signal in x,y, charge is the dominant, particularly in x – But also ~ 100 kHz signal (as well as other low freq components)– The frequency content between 0-200 kHz in x and y shows some shot to shot variation in this. – When offset large in y (6 mm), y trace looks similar to charge trace, and 300 kHz is enhanced in y. – No 6 MHz, as is the case since commissioning break – Droop towards end of train in charge signal (as in 3205, is this seen in FCUP/PI laser ?)

• INJ-BPM-03:– Can see 100 kHz in x which is small but in dominates other frequencies. Shot-to-shot variation.– Can suppress 100 kHz and enhance 300 kHz by steering.

• INJ-BPM-04:– Low frequency content 0 -200 kHz. 100 kHz probably there but not dominant.

• AR2-BPM-01: First time this BPM had been used– Large slope on x. . 100 kHz there but not dominant

• AR1-BPM-01– The usual dominant ~ 100 kHz in x

NOTE:

• I am normalising the x,y DFT so that the amplitude is measured in mm, following the recipe in ….

• \\Dlfiles03\alice\Analysis\Period 14 data\AP_period13and14\BPM\fouriernormalisation.pptx

INJ-BPM-01

Observe the same features as in #3205, -droop in x-low frequency (< 200 kHz) content in x/y but no single defined frequency dominating -300 kHz strong signal in BPM charge leaking to x and y

For Fourier analysis, take portion of bunch 6 – 60 μsec to remove early transient + droop

INJ-BPM-02 Nominal Set-UpInitial shot

Return to original settings 50 mins later after much steering, param scans etc

Relatively strong 300 kHz in x. Low frequency (< 200 kHz) content in x/y but, as BPM-01, no single defined frequency dominating. The amplitudes are higher (5-10 times) compared to INJ-BPM-01

INJ-BPM-02 Shot to Shot Variation

The low frequency (< 200 kHz) content does vary a bit shot-to-shot

After steering to get more

central x position on INJ-BPM-02

INJ-BPM-02 Shot to Shot Variation

Again, the low frequency (< 200 kHz) content does vary a bit shot-to-shot

After steering to get more

central y position on INJ-BPM-02

Parameter Variation vs INJ-BPM-02 observations

• Varied SOL-02 and Buncher Power independently. • Neither parameter had a dramatic effect on INJ-

BPM-02 observations. Frequencies and amplitudes changed slightly from nominal set-up

• Then changed SOL-01, with steering adjustment to keep centred on INJ-BPM-01. Again nothing dramatic …

• But one observation ….

Large Offset in Y INJ-BPM-02

y large offset and looks similar to charge trace. here have changed SOL-01 and H/VCOR-01 compared to nominal settings

Can see the 300 kHz is enhanced in y

And if large offset in X ?? INJ-BPM-02 • Looked through other data to see if the same thing happened

with large x offset • This conditioned occurred when varying SOL-02• 300 kHz is enchanced in x, but raw trace not very similar to

charge

INJ-BPM-03 • Evidence of fairly strong ~ 100 kHz was seen

previously (#3191)

There is a “cleaner” low frequency feature in x ~ 100 kHzBut the Fourier reveals the amplitude of this feature is SMALLER than on INJ-BPM-02. However the 300 kHz is very much suppressed and this makes the 100 kHz more noticable. Amplitudes in x,y, charge all suppressed compared to INJ-BPM-02

INJ-BPM-03 shot-to-shot

Again, the low frequency (< 200 kHz) content does vary a bit shot-to-shot

INJ-BPM-03 steer horizontally thru booster

• Steering directly upstream of BOOSTER i.e. steering through buncher not affected.

x offset large and negative, 100 kHz suppressed, 300 kHz enhanced compared to nominal steering

INJ-BPM-03 steer horizontally thru booster • Can change relative size of ~ 100 KHz or 300

kHz in x and y by steering vertically

INJ-BPM-04

NOTE MAGNIFIED SCALE

Again, the low frequency (< 200 kHz) content does vary a bit shot-to-shot

AR2-BPM-01

• Not been used before

Large slope in both x and y, somewhat unexpected since this is nominally zero dispersion

~100 kHz, 300 kHz freq components as usual

AR1-BPM-01

100 KHz enhanced significantly, in agreement with previous data

Conclusions on 100 kHz • There is some frequency content at ~ 100 kHz in x and y (but mainly x)

everywhere in the machine. It has different amplitude on different BPMs, and its amplitude relative to 300 kHz is also different on different BPMs

• 100 kHz is enhanced (and other frequencies supressed) in AR1, so that it is very obvious there. But it is seen in the injector, and before the booster.

• Relatively large 100 kHz amplitude on INJ-BPM-02 but there is also a large 300 kHz component here which disguises it.

• On INJ-BPM-01 it might be present but obscured by several frequency components 0-200 kHz.

• On AR1-BPM-01, 100 kHz in x is dominant and large• On AR2-BPM-01, 100 kHz in x is much smaller than on AR1-BPM-01

Other Conclusions

• Injector steering enhances different frequencies (100, 300 kHz) on the injector BPMs in different ways. Needs understanding.

• Droop towards end of train in x, y, charge evident in injector