Minutes for DRAGON Meeting May 31, 2005, 10:45 ============================================== Present: JDA, CV, PM, CR, HC, BW, MH, GR, JP, LB, AP, BG, CO, DH, DO, AO, JC, TK (rec.) 1 Hardware ========== 1.1 Leak in Front End --------------------- DH: Leak detector attached. Overnight pressure rose to 100 mTorr PM: FC1 broken current wire fixed CV: FC has wrong polarity. 1.2 Repair of Ion Chamber ------------------------- CR: Ion chamber left in "safe condition" with thick window on it when switching to DSSSD. DSSSD was pumped down according to old instructions. Ion chamber was mistakenly pumped down at the same time -> window of ion chamber sucked in. At least wires on first plane affected. But can be fixed. CR in charge. CR suggests to have spare parts in the future. DH: Instructions on pumping down have been updated. 1.3 Other Hardware ------------------ DH: ED1 conditioned to 165 kV. CR: Worked on NaI detector. Coincidence timing set up. JD: It is suggested to put labels on every hardware part and a circuit diagram on the website. Need also to update the members part of the website. 2. Stable Beams =============== 2.1 40Ca run with new source (CV) --------------------------------- Better stability than with old source, intensity about 1-2 enA (8+ charge state). Shows dE1 vs. dE2 for overnight run (see attachment). About 40 44Ti recoils appeared, 24 in coincidence. Beam was decreasing at end of run to 14 nA. Finest slits were set to 20mm, reducing the rate by about factor of 10. 400/s of leaky beam. SiN Boosters blown, only gas. Pile-up in the ion chamber can be seen. Blobs are Ti44 recoils of different charge states. Tails are different energy loss on plates. Main tail energy loss by scattering... Will be presented to EEC on Friday. JC: Overall transmission 4% from OLIS calculated. DH: This is very low. expect 20%. 2.2 Al Run ---------- Priority - Al or Mg? JDA: Al surface source is sparking. It is needed for Al beam; RF source for Mg. DH: People are working on surface source. CR: If we don't have enough time for Al, then Mg. But would prefer Al if enough time. It has been tried to use the RF source for Al, but there were problems. It is decided to have the surface source set up with Al and the RF source with Mg. JDA: Al run starts next Wednesday. No need to go back to Ca, only if there is spare time. CV: More SiN windows should be ordered. CR: Al beam starts about 17th. DH: Maybe Al calibration this weekend? Beam is ours for next 2 weeks! HC reports on DSSSD calibrations, see attachment: Si detector calibrated with triple alpha source for about 1h. Calculated gain and offset for each DSSSD channel, with manual Gaussian fits to the 3 peaks. Resolution of about .5% Calibration is accessible for root histograms and will be made available for online analysis. Run plan: JDA: Only single energy, i.e. only "babysitting" required. CR will prepare shift schedule. JDA: Everything must be written in notebook! CR proposes ELog like with TUDA. - accessible from off-site - can be searched - pictures can be included - handwritten drawings can be scanned and included No objections to try and practice it during stable Al run: Everything into ELog, no paper notebook. CR will make sure ELog is backed up. 2.4 Na (JC) ----------- Ran through 4 targets. "Chasing resonance" due to C build-up, so started at high energy moving down. C build up as function of time was measured. Corrections changed resonance profile. No resonance was seen when measuring a clean piece of Ni foil at 328 keV with Ne. JC: Maybe request beam time for 200uC 22Na in Ni foil 3. AOB ====== 1) Switching the room: Conference room is available Tue 10:45, and has videoconferencing facilities 2) JDA reports on Oak Ridge school and workshop (JDA, HC, MH), see attachment - School: lectures and hands-on experiments with 24 students - Workshop: 7 topics with different speakers Copies of lectures and workshop talks will be made available on CD. 3) Other announcements: - JDA: Photos of group members will be taken for the website in week of June 13! - JDA: A new student, Lisa, is going to arrive in two weeks. - Jonty will be on vacation for 1 week from Thursday. Meeting ends 11:57.