1. Downstream transversal sizes Rikard Sandström University of Geneva 2007-02-16 MICE detector meeting

2. Introduction Study A –Full phase space beam approach. Study B –Matched beam approach.

3. Setup, study A Geometry: –MICE stage6, with updated positions and iron shields. Iron shields not physically present in simulation, but using Virtual detectors at their surfaces. –Now with cryostats physically present. Field: –Holgers empty channel, beta 42 cm, 200 MeV/c field. http://mice.iit.edu/software/bfield/holger/FieldMaps24-01- 07/CoilconfigWangNMRironshield200MeVbeta42emptychannel.g4mice http://mice.iit.edu/software/bfield/holger/FieldMaps24-01- 07/CoilconfigWangNMRironshield200MeVbeta42emptychannel.g4mice –RF field OFF Beam: –The same “full phase space beam” as was used before.

4. There are no good events going through the cryostat!

9. Again… The large radius events are all low momentum, Hence, setting a minimum → pz fixing maximum rho !

10. Setup, study B Geometry: –MICE stage6, with updated positions and iron shields. Iron shields not physically present in simulation, but using Virtual detectors at their surfaces. –Now with cryostats physically present. –4.2 mm diffuser. Field: –Holgers empty channel, beta 42 cm, 140 MeV/c field. http://mice.iit.edu/software/bfield/holger/FieldMaps24-01- 07/CoilconfigWangNMRironshield140MeVbeta42emptychannel.g4mice http://mice.iit.edu/software/bfield/holger/FieldMaps24-01- 07/CoilconfigWangNMRironshield140MeVbeta42emptychannel.g4mice –RF field OFF. Beam: –Matched 140 MeV/c beam.

11. Study B progress Being simulated on the GRID now, but not yet finished. If there is time before the CM, other matched beams will be simulated too.

12. Conclusions The cryostat is no longer an issue. –At least not with the nominal field map. Setting TOF2 radius to –25 cm, losing events pz<225 MeV/c –30 cm, losing events pz<169 MeV/c –35 cm, losing events pz<129 MeV/c For results in terms of ratios lost, must wait for matched beam simulations (Study B) to finish.