HERA Beam Dynamics Meeting / Minutes : 18.03.2004

Attending :
M.Bieler, E.Gianfelice-Wendt, J.Keil, E.Kot, J.Maaß, E.Negodin, U.Schneekloth, M.Vogt, R.Wanzenberg, F.Willeke, ETC.

1. p-emittance blow-up by non-optimal e-tunes under collisions.
   • the e-tune procedure which is (so far) considered optimal :
     see minutes from 29.01.2004
   • when collisions are established at TuneStep-4 (f_x = 6.1 kHz), the tails of the e⁺ distribution are to close to the Q_x+3Q_s=integer resonance, get horizontally excited, transfer their excitation to the protons via the beam-beam interaction, and thereby degrade the p-emittance
2. [J.Keil] : to 12.09.2003 and 26.02.2004) (ps)
   • 3 ORM's compared :
     1. 12.09.03: helumsm, ZEUS-cal.=open
     2. 26.02.04: helum72, ZEUS-cal.=open
     3. 07.03.04: helum72, ZEUS-cal.=closed
   • phase jump at IP's :
     

     ZEUS-cal.	open	closed
     jmp@H1	.TRUE.	.TRUE.
     jmp@ZEUS	.FALSE.	.TRUE.

   • the calorimeter induced phase jump at the ZEUS-IP cannot be compensated by just correcting the GO SL
   • use 3 nearest independent magnets SL and NL to compensate the beating
3. Discussion on a new e-ramp & and e/p-lumi procedure (FileFolge):
   PLAN :
   

   FileFolge	Ee/GeV	e-optic	p-optic	e-collis
   e-ramp	12	inj	sep+corr=12inj	12-inj
   e-ramp	24.5	inj	sep+corr=24inj	24-rmp
   e-ramp	27.55	lum : TuneStep-1,Δf0=0, ZEUS-cal=open	sep+corr=27lum	27-lum
   		→ TuneStep-4, Δf0=300Hz, close ZEUS-cal
   e/p-lumi	27.6	lumi : TuneStep-4,Δf0=300Hz, ZEUS-cal=closed	sep+corr=27lum	-- ,, --
   e/p-lumi	27.6	lumi : -- ,, --	lumi	-- ,, --

4. [U.Schneekloth] : informal update on pentaquark states seen at ZEUS (strange/no-charm) and at H1 (no-strange/charm)

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