Longitudinal Bunch Profile Measurements Using WCM and Streak Camera Techniques

Reliable and precise longitudinal bunch profile measurements are essential for maintaining high-quality beams across the CERN accelerator complex. In the Super Proton Synchrotron (SPS), the longitudinal beam observation system utilizes a Wall Current Monitor (WCM) to measure the beam profile signal and is acquired by an oscilloscope operating at up to 40 GS/s. However, distortions caused by cabling, electronics, and attenuation between the beam pick-up and the oscilloscope affect the measured profile, requiring compensation based on the transfer function of the system. Alternatively, a streak camera system, used for the AWAKE experiment after extraction from the SPS, offers temporal resolution on the order of a few picoseconds with minimal signal distortion. This work presents the comparison between the bunch profile measured with the WCM in the SPS and the streak camera. The results, based on two different measurement techniques, will be processed and compared to assess precision and accuracy.