M9A Beamline

Beamline M9A views the beryllium production target T2 in beamline BL1A, as shown in Figure 3.1. Pions from the production target travel travel through a series of momentum-selecting dipole magnets (B1 and B2) used for bending the beam, as well as a series of quadrupole magnets (Q1-Q12) used for focusing. For experiment E838, a $\pi ^-$ beam of momentum 81.5 MeV/$c$ was stopped in the liquid hydrogen target located at the center of the RMC detector approximately 19 m downstream of the pion production target T2. The beam consisted of pions as well as muons from charged pion decay ( $\pi\rightarrow\mu\nu$) and electrons from ( $\pi^o\rightarrow\gamma\gamma, \gamma\rightarrow e^+e^-$).

Figure 3.1: A layout of the TRIUMF facility and the location of the RMC detector at the end of beamline M9 (channel A) at the Meson Hall.