Upload
moe
View
38
Download
0
Embed Size (px)
DESCRIPTION
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 - PowerPoint PPT Presentation
Citation preview
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