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 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 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 kHz. 100 kHz probably there but not dominant. AR2-BPM-01: First time this BPM had been used – Large slope on x 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\fouriernormali sation.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-Up Initial 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 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 kHz But 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 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 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