Post date: Apr 3, 2014 2:30:11 AM
We had a look at analysis of results from the tune data.
Suzie presented an analysis by David which showed tune variations in vertical and horizontal tune as a function of magnet current.
Ishi-san showed FFT results of the data sets for vertical and horizontal energy variation. Measurements indicated that the loss points were reasonably close to resonance lines. We now plan to take tune measurements at some further energy points to attempt to get a good measurement of the tune shift as the energy is increased.
We had some discussion about other measurements to take. We considered taking measurements of energy loss. Uesugui-san showed us a result using beam data on Monday, where he measured the synchronous phase as compared with RF voltage. The result looked just about statistically significant, but we thought we could probably do better with a dedicated measurement. He also showed what this should look like theoretically for different foil thicknesses.
Kuriyama-san showed some previous results where similar parameters were measured, altering the capture phase to generate oscillations in the RF bucket. He showed a good measurement precision.
Following discussion, we decided that the first measurement to make should be the transverse emittance growth. Two options here, either use a vertical scraper or a horizontal scraper (to get a handle on vertical or horizontal emittance growth respectively). The aim is to reduce the aperture and search for a faster loss in beam current. As the horizontal scraper is remotely operable, it was decided to use the horizontal scraper, so that we get the data in time.
After data taking we will introduce a slit in a dispersive region of the beamline. This will make the energy width of the beam small, enabling measurement of dispersion and maybe giving a better measurement of the energy loss in the foil.