2017-03 analysis summary¶
Data was analysed to ensure
- Correct operation of the cooling channel hardware from the beam's perspective
- Reasonable physics result
The data taken was from the 2017-02 7 cooling channel setting. Data was analysed with lH2 filled and lH2 empty (ISIS user run 2017-02) and with LiH installed and LiH removed (ISIS user run 2017-03).
The absorber performance was checked in two ways. In the first instance muon tracks measured in TKU were extrapolated to TKD, with "most probable" energy loss calculated using the PDG formula. The resultant momentum was compared with the momentum measured in TKD. The results are shown below. This indicates that the energy loss is reasonably consistent with the expected value.
In the second instance, the momentum loss between TKU and TKD was compared to the extrapolated height that particles had in the lH2 volume. The energy loss is pretty constant across the height of the absorber, providing evidence that the absorber was completely full.
The magnet performance was checked by examination of hall probe readings. The hall probe readout is consistent at the 10^-3 level between all of the 2017-02 7 datasets. Nb: HP67 is at the downstream end of TKU.
The hall probes readout every second. In order to examine the hall probe stability, a histogram was made of the hall probe readouts for runs with the absorbers indicated in the legend, for each hall probe. The hall probes seem to be pretty stable.
The beta_4d, beta_x and beta_y of the beam based on extrapolation from TKU tracker reference plane to the downstream systems (blue) was compared with the measured parameters measured at TKD and extrapolated through the downstream detectors (red). The blue vertical lines indicate the position of TKD stations. The level of agreement is in general pretty good.
lH2 Empty absorber¶
LiH Empty absorber¶
The general physics performance of the lattice seems compatible with expectations. Note the MC truth data at the bottom, indicating a rather hard amplitude aperture; which leads one to suspect that accounting for detector inefficiency will improve the results.
lH2 Empty - data¶
lH2 Full - data¶
lH2 Empty - MC Truth¶