Beam/ Halo Diagnostics R. Fiorito, A. Shkvarunets, H. Zhang Institute for Research in Electronics and Applied Physics University of Maryland Presented (with apologies) Michelle Shinn (JLab) 1 Goals: measure low intensity halo properties (distribution and emittance) in presence of high intensity but low emittance core Approach: use OTR or OSR and optical masking to separate out halo and core Two masking methods : I. Fixed (pinhole or stop); II. Adaptive (programable digital micromirror array)

OTR and OSR Halo Imaging Systems installed at FEL Site of OTR and OSR diagnostics experiments

Electron beam OTR Camera 2 Mask beam imaging camera OTR farfield imaging camera beam ( pinhole or stop ) (farfield OTR gives localized divergence within pinhole or outside stop) I. Fixed Optical Mask (used with OTR station at FEL beam dump) polarizer

II. Adaptive masking using digital micro-mirror array* *DLP TM 1100 Texas Instruments Inc micromirror size:  m x  m No of elements: 1024 X 768 pixels Array switching rate: 9600 patterns / sec PC interface: USB 2.0 micromirror Rotation axis

DMA Imaging System Developed at UMD/ UMER 180 Frames 32 mm 900 Frames 32 mm 5

Halo measurements at UMER (7 mA beam) using DMA Screen boundary

Dynamic Range Test of DMD with intense UMER beam and circular mask Integration Frames: 7 32mm

Dynamic Range Measurement using Circular Mask and intense 23 mA beam: DR ~10(5) mm 8 Reconstructed beam profile

1000 mm 500 mm OSR Port (2F06) Gallery optics: top view 1219 mm 457 mm DMA Camera 24 o Optics for DMA Halo Experiment using OSR (Installed at FEL 8/2010 ) Vault Optics: side view 5 m PVC tube FEL Vault ceiling Gallery optics: side view