I did not warn you about the Hall probes being useless. We have the complete map of D3 and D4 and know how to scale to the regions where we plan to use the field. I think I made a mistake trying to follow your humor, you an agressive tone that will now make me think twice before answering to your messages. Ramiro Ian Bearden wrote: > Hi Ramiro, > Your message did not, in fact, end in the trash bin. What is more, I have > looked at the field vs z that you sent to check that what is done in BRAT is > consistent, which it is. > > I was only trying to give the information that I have, sorry I forgot to > include your warning that the hall probes are useless. My mistake. You > get one beer, but don't give up since you are still in the running of 'Who > Wants to Get Drunk' > > Ian > > > -----Original Message----- > > From: owner-brahms-l@bnl.gov [mailto:owner-brahms-l@bnl.gov]On Behalf Of > > Ramiro Debbe > > Sent: Friday, October 12, 2001 4:58 PM > > To: brahms-l@bnl.gov > > Subject: Re: Magnets! (fwd) > > > > > > Here is a message that I sent to Ian about the Hall probe readout. The > > warning was clear but seems to have ended in the trash bin and thus > > jeopardizes my chances of digesting decent amounts of wheat juice. > > > > Ramiro > > > > ---------- Forwarded message ---------- > > Date: Thu, 27 Sep 2001 14:40:18 -0400 > > From: Ramiro Debbe <debbe> > > To: Ian Bearden <bearden@nbi.dk> > > Cc: Ramiro Debbe <debbe> > > Subject: Re: Magnets! > > > > I got your message and I will prepare a few plots of By as function of z > > so you can see how the field changes and check if the EEA is good. > > I will check the current to field calculation again, I would guess it is > > OK. I already checked before but there is a new table in the CH that needs > > some check. I assume whomever made the table used the fits I sent to the > > list server. > > The Hall probe readout for all magnets is available from the database. Go > > to the DAQ page and click "NEW IMPROVED - Keithley DVMs" > > You should be warned that the probes in D3 and D4 were placed too close to > > the edge of the gap where the values of By are very different from the > > average inside the gap. T3 and T4 were already in place and my arms are > > only that long. > > > > So, I will send you another message soon. > > > > Ramiro > > > > On Wed, 26 Sep 2001, Ian Bearden wrote: > > > > > > > > Hi Ramiro, > > > Pawel and I have been trying to begin to understand the FS > > data, and have > > > run into a small problem. I think that you are the only person > > who can help > > > us to solve ( and maybe even understand?) this. The problem is > > that we find > > > three different momenta in the three magnets D2, D3 and D4. I have not > > > fully checked D1 yet, but we could by correlating track > > projections to the > > > BB (or TPM1) vertex. > > > > > > I can see three things that could cause these differences: the > > first could > > > be geometetry of the detectors, since this would cause us to > > calculate an > > > incorrect bending angle, and thus wrong momenta. > > > Second, we use the effective edge approx, but we should not. > > The EEA should > > > work better for D2 than the others, but how good is it? Do you have a > > > feeling for how well the EEA should work, knowing the field > > maps you made? > > > Third, the calculated B field is not quite right. I suppose this can be > > > ruled out quickly by you, since you have done all the field > > mapping, and are > > > the only one who knows anything about the magnets. If I recall > > correctly, > > > you put Hall probes in each of the magnets, are these read out, > > and if so, > > > what do they say? > > > > > > I would really appreciate any suggestions you might have as to > > what may be > > > wrong, and what we might try to do to understand things. > > > Thanks! > > > Ian > > > > > > > > >
This archive was generated by hypermail 2b30 : Fri Oct 12 2001 - 12:33:54 EDT