An Ultracold Neutron Source for TRIUMF Jeff Martin University of Winnipeg TRIUMF Townhall Meeting Ultracold Neutron Working Group Aug. 2007 Coconvenors: Chuck Davis (TRIUMF) Akira Konaka (TRIUMF) Yasuhiro Masuda (KEK)

International Workshop: UCN Sources and Experiments Shameless advertising International Workshop: UCN Sources and Experiments September 13-14, 2007 TRIUMF, Vancouver, Canada http://www.triumf.info/hosted/UCN Registration is free, but please do register ~25 speakers from all over the world ILL, FRM-II, NCSU, LANL, PSI, KEK, Mainz, ... Supported by TRIUMF and TUNL

Charge (from U. Greife) 1) What is needed at TRIUMF to capitalize on the scientific opportunities currently available? 2) What are the scientific and technological development opportunities at TRIUMF for university and other external groups? (CFI focus) 3) What infrastructure and investment at TRIUMF is needed to meet them next scientific challenges in the next five-year plan? (5YP focus) As an outcome we would like a white paper from each working group which builds upon the TUG white papers, but additionally provides priorities and suggests which opportunities are to be addressed internally, and which could be met by external users in collaboration with TRIUMF.

Outline of White Paper Physics prioritized and realistic, as much as possible UCN Source proposed intensity at TRIUMF world context and relevance Required Infrastructure floorspace and shielding He liquefier Required funding CFI and collaboration, and international

Aug. 1 morning - plenary session, charge, and introduction of working groups 12:00 lunch 13:00 Welcome + Charge (Martin) (10+5) 13:15 UCN Sources Worldwide and for TRIUMF (Masuda) (45+10) 14:10 Photofission, (gamma,n) Sources and UCN (Behr) (10+10) 14:30 coffee (30) 15:00 SCRF joint session: Electron Linac Design (Koscielniak) (20+10) 15:30 UCN Infrastructure and Proton Hall Floorplan (Davis) (10+10) 15:50 Proton Hall Radiation Limits (Trudel) (10) 16:00 Discussion (Chair: Davis) (30) 16:30 tour of proton hall? (if desired) (Davis) (30) Aug. 2 09:00 Continued infrastructure Discussion (60) 10:00 UCN Physics Intro (Martin) (10+5) 10:15 UCN Beta Decay (Melconian) (20+10) 10:45 coffee (30) 11:15 n-EDM (Masuda and/or Hayden?) (20+10) 11:45 radioactive beams (Buchmann) (10+10) 12:05 lunch 13:15 gravity levels (Konaka) (5+10) 13:30 other physics (Martin) (15+10) 13:55 discussion of physics priorities and strategy (chair: Martin) (35) 14:30 begin writing more joint sessions draft Aug. 3 morning presentation Aug. 3 morning - presentations of results from the working groups. Agenda

UCN and SCRF/ISAC interface issues proposal for UCN (CFI 2008) 10 uA at 25% duty cycle (1 min on, 3 min off) use BL4A (TISOL) duty cycle is incompatible with ISAC targets, but may be necessary for low background for UCN experiments space requirements in proton hall can be managed (diagram to be crafted by Davis, Masuda, et al) strategy for UCN (after discussions with SCRF/accel) accept beam on BL4A when ISAC 2nd target station is off, or part-time during target development periods, or when e-linac in operation (This could be a substantial part of the BL4 time initially available.) accept sole user status in low-intensity periods so that duty cycle can be achieved at source.

Future Upgrades (5YP and beyond) other options for duty cycle fast kicker + local beam dump in hall local shielding of dump required reorganization of proton hall more appropriate to be on same time scale as ISAC 2nd target station manipulation of internal cyclotron beams requires further study carbon stripper with mechanical motion in/out to pulse beam difficult other options besides sharing BL4 with ISAC two stripper foils on same extraction probe + septum difficult, more appropriate for BL1 BL1, BL5 major reconstruction (gamma,n)