Minutes for DRAGON meeting, November 22nd 2005. ************************************************* Present: Christof Vockenhuber, Jac Caggiano, Peter Machule, Mike Trinczek, Dave Ottowell, John D'Auria, Dave Hutcheon, Goetz Ruprecht, Dieter Frekers, Chuck Davis, Jonty Pearson, Chris Ouellet (recorder). 0.Previous minutes ~~~~~~~~~~~~~~~~~~~ No comment 1.Hardware Status ~~~~~~~~~~~~~~~~~~~~~~ Jonty shows graph of Acceptance vs. Energy mistune with Geant simulation and alpha data. DH: Acceptance is 5D - this is a projection into 2D LB: Quite a mistune JC: Small tubes? Big tubes? JP: Small. DH: There's a connection between position but not enough to change data LB: All counts taken? JP: Yep. LB: Possible spectral changes. JD: There is a laquered coat on the source. JP: We need to measure the layer, Geant change would be difficult JD: Affects any of published results? Many: Not really. Systematically things would go up. JP: Hit pattern on end detector is pretty rough, perhaps losing some above DSSD JC: Micro channel plate? JP: No. JP: Most recoils still fall within the 19 mrad acceptance Many: Missing more than 1 mrad regardless, Geant doesn't reflect reality We should figure out nevertheless and repeat these in January. Other hardware: PM: It's all good. JD: ED1 has had tests performed on it and is doing well. CV: Reached 168 JC: Replacements - 2 companies replied back ~$10000 a peice or perhaps even better they may make 3 or 6 for that price, Morgan and CoorsTek JC: They admit they don't necessarily know all the problems with it. JD: California? JC: Yep. LB: On completion or in advance? JC: $1000-2500 non-refundable. JD: We've used Coors before for plate with a lot of channels on it. PM: Design that it isn't just a tube makes it so much more expensive, perhaps using glass or pyrex DH: Why didn't we do this earlier PM: Discussion has been had, but not clear why we're stuck on these materials JD: Miguel is the guy to ask JC: Outer lip is also a molding problem. PM: In both cases a tube is much simpler JD: We need more expert opinion DH: I still have 10k canadian in this years Dragon account and we need to use it very soon JD: Agreed. If the company knows what they're doing we should jump on it, look into references DO: We buy a lot of power supplies from HayWood (Spelling?!?) DO: Any remaining ceramics? Many: No. Conclusion: Jac will follow up and we'll make final decisions 2. Current Run Status ~~~~~~~~~~~~~~~~~~~~~~~ CV: We got beam on Friday, good for us since it allowed to discuss proceedure for energy spread minimization CV: There have been a number of discrepancies and dicussion about beam energy CV: Prague magnet is meauring probably 5keV off. CV: Not quite consistent yet with what we expect in terms of strong resonances but Dragon seems much more on the mark than the prague. CV: Beam centering proceedure may not be that accurate DH: Most Dragon/Prague magnet measurements are ~3 keV discrepant CO: Consistently higher than the prague DH: 1127 was the energy we ran at JD: Previous measurements? CV: Too large steps then, we can't really compare DH: All we know is that we started off with a 0.4% energy spread with buncher LB: There may be a 1 or 2 keV random energy change DH: It's hard to do better than 1keV Many: Discussion centers on 2 measurements made right between resonances that are very low. DH: Product of charge state x field are the same to within 0.07% for 11+ and 14+, magnets are almost 1%. JC: We should have a plot of our E vs. the prague E CV: Will do JC: They have no object and image slits - that might be a problem if they're just using a faraday cup CV: Leaky beam2. CV: We got beam on Friday, good for us since it allowed to discuss proceedure for energy spread minimization CV: There have been a number of discrepancies and dicussion about beam energy CV: Prague magnet is meauring probably 5keV off. CV: Not quite consistent yet with what we expect in terms of strong resonances but Dragon seems much more on the mark than the prague. CV: Beam centering proceedure may not be that accurate DH: Most Dragon/Prague magnet measurements are ~3 keV discrepant CO: Consistently higher than the prague DH: 1127 was the energy we ran at JD: Previous measurements? CV: Too large steps then, we can't really compare DH: All we know is that we started off with a 0.4% energy spread with buncher LB: There may be a 1 or 2 keV random energy change DH: It's hard to do better than 1keV Many: Discussion centers on 2 measurements made right between resonances that are very low. DH: Product of charge state x field are the same to within 0.07% for 11+ and 14+, magnets are almost 1%. JC: We should have a plot of our E vs. the prague E CV: Will do JC: They have no object and image slits - that might be a problem if they're just using a faraday cup CV: Leaky beam rate is significantly lower and beam spot is tight so that's good news CV: Low energy tails might be the reason when it's not as well tuned as it was for these runs DH: Should we do more on resonance before? CO: I'm not 100% convinced, I think we should JD: Maybe another point JC: Perhaps check RF vs. Gamma ray for more confidence in Energy measurements? 3. Other news ~~~~~~~~~~~~~~~~~~ JD: Lake louise Banff conference in February for graduate students. NIC conference also in June, deadlines are coming up for that as well.