3211 Sat 10th November 2012

Summary

• BPM normalisation error studies on INJ-BPM-01 : using different (rack room) cards.

• Swapping of H/V cables on INJ-BPM-01 few times within short time invervals.

• INJ-BPM-01 signals vs SOL-01• Record AR1 BPM signals to study frequency contents.• INJ-BPM-03 signals simultaneously with INJ-FCUP and PI

laser power trace. • Key finding: The 6 MHz seen in October ‘12 data is not

present now.

BPM normalisation error studies on INJ-BPM-01 : using different (rack room) cards.

With the ‘normal’ rack room card (08) this is an example of what the x,y, charge signals look like

Note:-Droop on x and chargespikes on y

BPM normalisation error studies on INJ-BPM-01 : using different (rack room) cards• Take fourier of the bunch train signals with initial transient

(6.25 μs) and final droop (25 μs) removed => 70 μs section of the train

whole spectrum including aliasing, no 6 MHz evident

minimum frequency resolvable for 70 μs train is 1/70 μs = 15 kHz

BPM normalisation error studies on INJ-BPM-01 : CARD 06

BPM normalisation error studies on INJ-BPM-01 : CARD 04

BPM normalisation error studies on INJ-BPM-01 : CARD 08

NB mistake here

Conclusions on INJ-BPM-01 vs. BPM attentuation

• The 300 kHz amplitude in the sum_voltage signal seems to depend on the BPM attenuation. Higher attenuation, lower amplitude.

• Behaviour of other low frequency components not very clear.

Swap Cables – X, Y, CHARGE • Switch cables for H pickups to V pickups; and vice versa.

attenuation = 15 attenuation = 18reference

swap cables

swap cables back

Swap Cables – fourier transforms

attenuation = 15 attenuation = 18reference

swap cables

swap cables back