Minutes Dragon Meeting Jan 9th 2007 Present: DAH, CD, DFOT, LB, PM, CR, MT, JP, CV (recorder) Start 2:15 pm 1) previous minutes and business arising: corrections: last line: 20Ne instead of 22Ne pipe for 22Na(p,g) box: 6 inch not 4 inch as drawing suggested progress on REAs: REA 747 (accidentally) took off ^Ö solar cell detector array REA 750 (TUDRAGON) should start soon 22Na(p,g): DAH replied to UoW answer concerning vacuum: instead of a Viton sealing we could use soft metal, Mike McDonald is testing that on existing boxes for ISAC-II We need 1E-7 range which we can achieve with Viton. A cold trap usually helps to reduce Carbon build up. Box is a standard ISAC box. Digital electronics: should bring advantages at higher rate. Hardware is here, software was emailed to CR. DAQ group will provide special CAMAC controller: the question is if we need it only for testing or for the entire experiment? JP recommends setting up the DAQ here and then transferring everything to UoW. 8 channels are available, so rastering information and anticoinc. signals could be fed into the data stream as well. Detectors (ones used for Goetz^Òs 22Na experiment) are cooling down. 2) Hardware: Alignment: DAH circulated another report. DFOT made careful measurements of the gas cell box movement under pumpdown: The upstream collimator moved 1.8 mm east, the downstream one 1 mm. The external boxe moved ~1mm east. A few ISO clamps on the east side were found loose on the section to the pumps ^Ö PM fixed that. Now there is only a 1 mm movement east by the gas cell, no movement by the box. There are 2 posts inside the box which prevents it from collapsing under vacuum, but they are below the gas cell which causes some tilting. Possible solutions were discussed: CV ^Ö gas cell as insertion fixed to the pumping tubes rather to the lid. CR ^Ö additional posts. JP ^Ö screws on the gas cell can be extended to almost touch the other side. Alignment is critical for the max. cone angle since there is only about 1 mm nominal clearance. Also radioactive beam can spill if it is clipped. Question of the measurements: are they reproducible? Another measurement on MD1 revealed that it is tilted about 3x larger than originally thought. The beam is pointing uphill. Either the pillar on the south wall has sunk or the front end risen. For future monitoring and before any correction a Total station from beamlines will be used. Bruno Gasbarri will be consulted, but the procedure should be well documented and understood by DRAGON people. Question about the alignment of the EDs. It^Òs hard to check and to correct since they are inside the vacuum tank. Optional: more steerers could be inserted (especially vertical ones) along the beam line. MT: EMMA should be aware of lessons learned at DRAGON: proper alignment marks on all components for future checks. Mitutoyo: DFOT: requirements are 100 mm travel, 0.1 mm accuracy, RS232 output and it should not forget position under any circumstances. A phone call with a representative did not give the right answer. DFOT will inquire more^Å Recalibration at a known position might be ok. TRIUMF Budget: CV presents a proposed change of the detector setup including the 2nd MCP: Moving the final slit box ~40cm downstream, so the 1st MCP (small, existing one) is mounted at the front and close to the focus point. The 2nd MCP will be mounted at the end facing backwards, which gives a flight path of ~60cm. DSSSD and IC should be mounted as close as possible to the final slit box without the bellows and cross needed for pumping. This requires a few items: changing top and side plates of the final slit box, a new box and (possible more convenient) mounting for the DSSSD, the IC moveable to the side, a new stand. The 2nd MCP needs several grids for the mirror and MCP assembly, linear motion feedthrough (motor driven), a voltage divider. The 26Al detection setup requires a rotating plate plus drive and 2 NaI in close geometry, possibly mounted on an additional lid to the existing DSSSD box. CR: EPICS drive for the iris (only the opening, not the position) MT/DH: (low intensity) position monitor in HEBT 2 beam line to assist beam tuning to DRAGON. CV/PM: check if last gate valve is reparable (has a leak) or if we should buy a new one. 3) Beam time request: JMP sent out a call for beam time requests for the Spring/Summer 2007 schedule. OLIS ECR should be installed in the shut down. CV: Keerthi wants a list of all possible beams, so he can test them in the first time. He fears that once it is running there will be hardly any time for developing new beams. These items will be discussed next week. 4) Conferences ^Ö Workshops: DAH presents a list of for us interesting conferences in 2007: Budget allows for one conference per person (excluding people with other funds). Nuclear Physics in Astrophysics III was considered as the only one where we should be present. It would be nice to present new results (which might be available in the second half of 2007). 5) 40Ca(a,g)44Ti: CV presented an update on the analysis: Most of the work is done, 44Ti recoils, R-value (except for the runs with SB problems). Main topic is now charge state distributions: 40Ca FCCH/FC4 ratios show large scatter. Also some offset (probably caused by not selected charge states hitting a wall and creating electrons) on low current measurements are present which have to be considered. 44Ti coinc./singles ratio of selected runs give idea of BGO efficiency. Two sets of runs, the first ones with values of about ~55% and the later ones with ~80%. These numbers will be compared with GEANT simulations. Question on final uncertainty: depends on the position on the excitation curve. Beam normalization and CSD will dominate except for runs with very low yield (dominated by counting statistics) and runs at strong resonances where 44Ti CSD was measured directly. Analysis should be finished by the end of the month. 6) AOB: LB: REA 747 design will be discussed at the next meeting. End of meeting 4:20 pm