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H plane spectra

V plane spectra

Base-Band Q (BBQ) Measurement with Direct Diode Detection (3D)

The plots to the left show spectra of the SPS fixed target beam. The upper and lower plots correspond to the horizontal (H) and vertical (V) planes, respectively. The plots present spectra of signals given by the 3D-BBQ-Measurement prototype WITHOUT ANY EXTERNAL EXCITATION of the beam. The signals were acquired with a PC sound card and processed off-line. Go to the SPS Results for further details.

The signals whose spectra are seen can be downloaded as a .wav file and THEY CAN BE LISTENED TO! The left (L) channel contains the record of the H plane signal and the right (R) channel - of the V plane. The .wav file can be downloaded from the list below.

The lower frequency content (left side parts of the plots) corresponds to the synchrotron motion of the beam and the traces above 15kHz - to the betatron motion. Since the betatron frequencies are above 15kHz, they cannot be heard easily in the original record. For this reason I prepared versions of the record, which are stretched in time 4 times to reduce all frequencies by the same factor. The longer machine cycle helps also to follow what happens with the synchrotron frequencies.

I prepared two .wav files, containing separated H and V signal records, each copied to both, R and L channels. The .wav files can be downloaded from the list below. Headphones help a lot to resolve different components.

Me in BA2 making measurements on the SPS with the very first BBQ prototype

(c) M.Gasior, CERN-BE-BI. All rights reserved.