1. E906 Changes Paul E. Reimer 8 December 2006 Spectrometer Location Spectrometer’s 2 nd magnet Hodoscopes –Scintillator for Station 1 and 2 –Photomultiplier tubes DAQ/Trigger

2. 2 8 December 2006 E906 Changes since Inception Location Fermilab Original Meson East is now not Available Superconducting Cryo- Module Test Facility (SCMTF)

3. 3 8 December 2006 E906 Changes since Inception Meson West NM4 (KTeV) Location Fermilab (cont)

4. 4 8 December 2006 E906 Changes since Inception Location Fermilab NM4 (KTeV) –Beam lime below grade allows for a horizontal bending spectrometer—bends  + and  - into earth. Easier assembly for magnets. –Possibility to use KTeV Magnet –Nicer facility for physicists Meson West –Vertical bend spectro.—bends  + into earth. –2 nd magnet (SM3) must be assembled (but is available)

5. 5 8 December 2006 E906 Changes since Inception Beam Request and Structure Old Plan was for 1 £ 10 12 protons/s and accumulate 5.3 £ 10 18 protons on target in 1 year –Unacceptable impact on other Fermilab proton users New Plan –Cut impact on other proton users by ¼ –2 £ 10 12 protons/s –5 s long slow extraction spill –Total of 5.3 £ 10 18 protons in 2 years (with some allowance for normal Fermilab maintenance shutdowns, etc

6. 6 8 December 2006 E906 Changes since Inception M1 Magnet New coils Reuse whole pieces of SM12 magnet yoke (SM12 was the 14.4 m dipole used by E866)

7. 7 8 December 2006 E906 Changes since Inception 2 nd Spectrometer Magnet Originally proposed Jolly Green Giant, 1.65 T-m (500 MeV p T ) 80 £ 50 in. –In use by E907/MIPP (although their future is uncertain) –Possibly in need of repairs Other magnets have become available: –SM3 (BTeV is no longer with us) 3 T-m, (900 MeV p T ) 60 £ 60 £ 210 inches –KTeV Magnet (CKM and KAMI are no longer with us) ¼ 2 T-m, (600 MeV p T ) 2m £ 2m £ 200 inches Impact on measurements (Monte Carlo from ACU students): –Momentum (and hence M and x F ) resolution dominated by multiple scattering and energy loss in absorber until p T kick < 200 MeV –Acceptance also approximately the same for p T kick of 900 to 400 MeV Plan: –MWest—Fermilab reassembles SM3 –NM4 (KTeV) relocate KTeV magnet to appropriate position

8. 8 8 December 2006 E906 Changes since Inception Scintillator for Hodoscopes: Station 1 and 2 Original plan was to purchase new material for all stations Current plan: –Purchase new material for Stations 3Y, 4Xa, 4Xb, 4Y (Abilene) –Recover material for Stations 1X, 1Y, 2X, 2Y from HERMES muon hodoscopes which will have to be refashioned and polished in one dimension. (Naomi Makins, Illinois) –Purchase new light guide material for all stations.

9. 9 8 December 2006 E906 Changes since Inception Photomultiplier Tubes for Double Ended Readout Original plan was to purchase ¼ 220 new 2” PMT’s to add double ended readout to Station 3 and 4 Hodoscopes, in addition to reusing E866 PMT’s Current plan: –Recover 250 1.5” PMT’s/bases/shields from ZEUS at DESY (Argonne’s HEP) rather than new purchase (more could be available) –Cockroft Walton PMT bases with power supply –Need to test PMT’s, both ZEUS and old E866

10. 10 8 December 2006 E906 Changes since Inception DAQ Old plan was to borrow Fermilab E871 DAQ running Fermilab DART system –Still available to us (I verified this in November) –Do we really want the DAQ running on 10 yr old hardware? –DART is no longer supported at Fermilab; although, there is no operational, Fermilab-supported system appropriate for E906 Solution: –JLab CODA system –Need to implement Nevis bus readout –Need to implement FERA readout Either solution will need local (collaboration) expert(s)

11. 11 8 December 2006 E906 Changes since Inception Trigger Old Plan was to Implement in copies of LeCroy Logic Units –Units no longer available –Expensive to duplicate units –Technology has evolved New plan (Rutgers, Ron Gilman) –Implement in FPGA –Much cheaper, more flexible logic

12. 12 8 December 2006 E906 Changes since Inception Bottom Line E906 has changed in terms of implementation Physics goals have not changed and will be reached with new configuration Hope to start construction in 2007 and start taking data in summer 2009