HERMES dipole magnet model for CBM CBM Collaboration Meeting September 25-28,2006 Pavel Akishin Elena Litvinenko Victor Ivanov LIT JINR, Dubna

Elena Litvinenko CBM Collaboration Meeting September The available magnetic field maps… cbmroot/ AUG07 / FieldActive.root FieldMuonMagnet.root FieldMuonMagnet_small.root cbmroot / FEB 07 / FieldActive.root FieldAlligator.root FieldActive_Bs.root FieldDipole.root FieldHera.root FieldHeraP.root FieldHeraS.root FieldIron.root FieldMuonMagnet.root

Elena Litvinenko CBM Collaboration Meeting September … and the “Active” magnet geometry 1.8 m 4.24 m

Elena Litvinenko CBM Collaboration Meeting September … and the “MuonMagnet” geometry 1m 2.9 m MuonMagnet

Elena Litvinenko CBM Collaboration Meeting September The new addition to cbmroot magnets Input data – one A4 page with a schematical view and the basic parameters of the dipole magnet from the HERMES experiment at DESY Motivation – checking the chances to use the existing magnet for CBM

Elena Litvinenko CBM Collaboration Meeting September D model for TOSCA calculations HERMES magnet model:

Elena Litvinenko CBM Collaboration Meeting September Field map “FieldHermes” for cbmroot

Elena Litvinenko CBM Collaboration Meeting September

Elena Litvinenko CBM Collaboration Meeting September cbmroot geometry “magnet_hermes.geo”

Elena Litvinenko CBM Collaboration Meeting September m 1.9 m 2.1 m 1.75 m 1.12 m 25º 1.19 m Target (-11.7cm) Angular acceptance of the magnet Integral = 0.76 Tm Hermes

Elena Litvinenko CBM Collaboration Meeting September m 1.12 m Modification of the magnet geometry 1 m 1.41 m 1.61 m Hermes HermesE

Elena Litvinenko CBM Collaboration Meeting September The changes of the coil current geom: magnet_hermesmagnet_hermes_e.geo field map: Hermes HermesEn HermesE Nominal current: 1500A Number of coils: 2 Turns/coil: A 1650 A

Elena Litvinenko CBM Collaboration Meeting September m 1.9 m 2.1 m 1.75 m 1.42 m 25º 1.51 m Target (-63.9 cm) Modified angular acceptance Last STS detector 1 m Integral = 0.79 Tm HermesE

Elena Litvinenko CBM Collaboration Meeting September The most significant field component |By| (z), x=y=0

Elena Litvinenko CBM Collaboration Meeting September |By| (z,y) x=0 for HERMES

Elena Litvinenko CBM Collaboration Meeting September Available Field Maps namesymmetry x,y ranges [cm] z range [cm]grid step Active1/8 [-150,150] [-300,300]1 cm MuonMagnet_small1/8[-150,150] [-250,250]1 cm MuonMagnet1/8[-150,150] [-450,450]2 cm Hermes->HermesE 1/4[-300,300] [-450,450]2 cm

Elena Litvinenko CBM Collaboration Meeting September Together with the existing field maps

Elena Litvinenko CBM Collaboration Meeting September Field Integrals along z axis (z1,z2) [Tm] FieldMap:(-50,50cm)(-50,100)(-50,200)(-100,100)(-200,200) Active MuonMagnet Hermes HermesEn HermesE

Elena Litvinenko CBM Collaboration Meeting September Existing maps: |By| (z,y) x=0

Volker Friese CBM Simulation Meeting 15. September And with “Hermes”: |By| (z,y) x=0

Elena Litvinenko CBM Collaboration Meeting September The results HERMES magnet model is available The variant of the minimal magnet modification is proposed to improve the angular acceptance The files are available for the simulations : / u/litvinen/cbmroot/input/ FieldHermes.root FieldHermesEn.root FieldHermesE.root /u/litvinen/cbmroot/geometry/ magnet_hermes.geo magnet_hermes_e.geo -”-