2023-01-16

Emi measured cable lengths to get the time delay from the cables

Initial beam intensity was lower than expected and the signal on the BPM was also low. The scope was connected to different section of the BPM which improved the signal. However, the beam intensity was still low when using our RF programme

The injection energy in the AWG script(s) was 11.0009 MeV, lowering the AWG script injection energy to 10.57 MeV improved the beam intensity. We think this is due to a frequency mismatch - either due to injected beams having lower energy than expected or due to a discrepancy in the field model. The frequency at injection was later measured at 1.5625MHz.

After the AWG script was corrected we were able to run a beam at 80MeV. However, we did not observe any betatron oscillations when the kicker magnet was activated.

We believe that was due to the orbit radius being smaller than the radius of the extraction kicker. Tests were done with 90 and 100MeV RF programmes.

Energy of the accelerated beam was increased until the effect of the extraction kicker could be seen in the beam loss measurements. This meant that we could be certain that the beam was passing through (or near) the extraction kicker. However, we still had difficulty observing betatron oscillations from the extraction kicker.

We used a regular KURNS RF programme to accelerate a beam to extraction energy and activate the kicker (at amplitude 40kV). Here a sideband in the frequency spectrum was observed. However, this was unable to be replicated at lower kicker amplitudes. This RF programme also did not have a flat top section.

Additionally, repeated flat top sections of 6 ms over loaded the RF amplifier. Reducing the flat top to 2 ms stopped the amplifier from tripping. In future, we could reduce the repetition rate to reduce the load on the amplifier

See 2023/01/16 log book below