TEST BEAMS Stanford Linear Accelerator Center Ted Fieguth DoE/SLAC Program Review April & May 1, 1997

TEST BEAMS Stanford Linear Accelerator Center Introduction Test Beam Coordination and the SLAC Program Available Test Beams How Parasitic Beams are Produced Some Typical Results List of Proposed Test Beam Experiments Selected Tests and Their Goals Possible Near Term Test Schedule Possibility of Pion Beam Tests Conclusions and Goals Ted Fieguth SLAC DoE/SLAC Program Review April & May 1, 1997

Talk Presented at... Stanford Linear Accelerator Center Directorate SLAC Program Coordinator C. Field Test Beam Coordinator T. Fieguth* Test Beam Users Safety Overview Committee D. Fryberger Radiation Physics ESA: S. Mao FFTB: S. Rokni Accelerator Dept. ESA: R. Erickson FFTB: R. Iverson Experimental Facilities Dept. Area Manager ESA: P. Anthony FFTB: A. Baker Test Beam Coordination *R. Gearhart, now retiring, coordinated Test Beams for 25 years

Primary or Parasitic Test Beams are available in ESA and FFTB Stanford Linear Accelerator Center FINAL FOCUS TEST BEAM END STATION A

How Parasitic Secondary Beam is Produced* 5-10% of SLC beam is scraped on sector collimators. Bremsstrahlung photons go straight head downstream,through the bending magnets striking a 0.7 X0 copper target producing electron-positron pairs. Electrons that are within a fixed angular acceptance and adjustable momentum acceptance enter the A-line and are transported to End Station A (ESA). Dipole Magnet Stanford Linear Accelerator Center * This method of obtaining test beams was suggested by A. Odian and developed by L. Keller and others

Test of Tagged Photon Production for GLAST ( T ) Stanford Linear Accelerator Center · Test of prototype GLAST calorimeters in electron beam · Wire chamber tagged photons >200 MeV · Lower energy untagged photons also present Apparatus being tested

Measurement of Low Energy Electron Yield during 1996 GLAST Test Stanford Linear Accelerator Center Electron beam: GeV electron beam. 120 Hz  p/p ~  ± 1%  x,y ~ cm  ~ ±1 mrad, mostly from scattering. Energy in Pb Glass Photon beam: Generated by ~ GeV, elec/ pulse ~  / pulse >10 MeV  energy measured by GLAST calorimeter.  x,y ~ 1-2 cm  ~ ±1 mrad ( Daniel Engovatov et. al. )

Typical Calorimetric Measurement of Particle Flux W. Bugg et. al., U. Tennessee Stanford Linear Accelerator Center Measurement of 13 GeV electron flux per pulse in FFTB during test T405 of the Tungsten-Silicon Sampling Calorimeters designed for E144 for recording energy of scattered e-, e+ and  ‘s.

ESA Data Aquisition System Maintained and Available for Users Stanford Linear Accelerator Center Roving VME can be moved about ESA floor Users can control Stepping Motors etc. 1 Mbyte/sec SCS Tape Silo Beam Monitoring Local Data Logging 8mm tape Online Analysis Workstations USERS INPUTS

1997 Test Beam Proposals Stanford Linear Accelerator Center

GLAST Science Prototype Test Beam Setup Stanford Linear Accelerator Center GLAST PROTOTYPE TEST VIEWGRAPH FROM BILL ATWOOD

Stanford Linear Accelerator Center PROPOSED NEAR TERM TEST SCHEDULE Stanford Linear Accelerator Center

ESA SPECTROMETERS Stanford Linear Accelerator Center PHOTOGRAPH OF ESA SPECTROMETERS

Conclusions and Goals Stanford Linear Accelerator Center SLAC continues to provide necessary and useful electron positron and photon Test Beams for many Users The Proposed Near Term Schedule is not crowded and will be achieved Ted Fieguth SLAC DoE/SLAC Program Review April & May 1, 1997 Conclusion: Goal: Maintain commitment to provide SLAC Test Beam Facilities to the user community Better understand the Test Beam capabilities and improve where possible Work to provide and maintain a low energy pion beam. Improve information regarding Test Beams on the SLAC Web Site