Beam Set-up

1. Beam Set-up Nicola Mazziotta INFN Bari mazziotta@ba.infn.it Mar. 20, 2006

2. Photon tag set-up l D δ pe θ(rad) = 0.3 B(T) l(m)/p(GeV/c), δ(m) = D θ = 0.3 B(T) l(m) D(m)/p(GeV/c) Set B to the max value (0.9 T) in order to have the beam axis in the middle of SSD (black arrow) Perform an alignment run with pions Decrease the magnetic field to the B* in order to have the beam axis (green arrow) outside the plastic scintillator used in the trigger downstream the SSD, but within the dump Residual electron momentum (pe*): 0.3B*l/ θmax  pe*  0.3B*l/θmin, p=pe-pe* θmin = θ – 0.5 w /D, θmax = θ + 0.5 w /D w = SSD acceptance width (about 6-7 cm) Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

3. Photon test beam set-up and trigger Beam: electron/positron EM Cal SSDs 2 SSDs (1%X0) S4 S2 C2 (3%X0) GLAST CU S3 C1(3%X0) Sh S1 (2.5%X0) TRIG = S1 S2 S4 Sh C1 C2 S3 Critical parameter: the angle θbetween the electron and the photon θ = θout - θinp, Δθ2 = Δθ2out + Δθ2inp + …. Δθ2inp(out) = s/(12 d) Where d is distance between the SSDs and s is the SSD pitch (228 μm) Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

4. T9 beam area (dimensions are in cm) To be removed 120 300 D U M P 800 480 350 200 120 160 HARP TPC CU MNP17 240 220 Counting room far 8 m Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

5. Electron TRIG = S1 S2 S3 Sh C1 C2 TRD Hadron TRIG = S1 S2 S3 (Sh + C1 + C2 + TRD) Pion TRIG: S1 S2 S3 (Sh + C1+TRD) C2 C1 to select electrons+muons and C2 to select pions (p>3 GeV/c) Electron/hadron PS test beam set-up and trigger Beam: negative/positive polarity p = 1-15 GeV/c EM Cal SSDs S4 S2 C2 (3%X0) TRD (12%X0) GLAST CU S3 C1(3%X0) Sh S1 (2.5%X0) 2 SSDs (1%X0) Magnet OFF The TRD improves the electron identification Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

6. T9 beam area (dimensions are in cm) To be removed 120 300 D U M P 800 480 350 200 120 160 HARP TPC CU MNP17 TRD C2, 300 cm 240 220 Counting room far 8 m Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

7. “Clean” low energy e PS test beam set-up Beam: negative/postive polarity p = 0.5 - 3 GeV/c D = 2 m 2 SSDs (1%X0) EM Cal (rad Veto) S2 C2 (3%X0) TRD (12%X0) C1(3%X0) GLAST CU Sh S1(2.5%X0) Magnet ON Maximum B(T) = 0.9 d = Bending length = 0.5 m D = 2 m Beam/photon separation = 27cm/p(GeV/c) S3 Option: magnet at 45° with respect to the beam axis Maximum B(T) = 0.9 d = Bending length = 0.7 m D = 2 m Beam/photon separation = 38 cm/p(GeV/c) Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

8. Timing T9 beam area S1 S2 C1 C2 …. CU Counting room NIM modules: Trigger 100ns 200ns 0 ns 200ns VME modules: DAQ 500 ns Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

9. 120 300 D U M P MWPC 40cmx40cm 800 480 350 120 200 200 150 160 HARP TPC 50 Rail C2, 300 cm 240 220 Counting room far 8 m T9 beam area (dimensions are in cm) Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

10. T9 beam area (dimensions are in cm) To be removed 120 300 D U M P 800 480 350 120 200 160 HARP TPC C2, 300 cm 240 220 Counting room far 8 m Nicola Mazziotta, INFN-Pisa Mar. 21, 2006

11. PST9 Counting room Nicola Mazziotta, INFN-Pisa Mar. 21, 2006