SCAPA Scottish Universities Physics Alliance AWAKE Oct Strathclyde programme: beam and plasma diagnostic Prof. Dino Jaroszynski and Silvia Cipiccia University of Strathclyde SCAPA Scottish Universities Physics Alliance AWAKE Oct Outline of talk Plasma characterization with THz-TDS Beam diagnostic: pulse length measurements THz-TDS/CTR Electron energy measurements Conclusions and future work AWAKE Oct. 2012SCAPA Plasma characterization Plasma for AWAKE: Li or Rb vapour, density cm -3 Requirements: Density uniformity 30 ps (sampling window) From the time resolve E(t) E() Reference signal E 0 (): THz pulse preceding the discharge Jamison,and Jaroszynski, J. Appl. Phys. 93, 4334, 2003 AWAKE Oct. 2012SCAPA Plasma characterization Jamison,and Jaroszynski, J. Appl. Phys. 93, 4334, 2003 Experimental at Strathclyde: setup E(t) Phase shift: Field amplitude AWAKE Oct. 2012SCAPA Plasma characterization By simultaneously comparing the phase delays and the transmission cut- off with a reference phase delay we expect to determine the plasma density to within 0.1%. Spatial distribution spatially resolved phase measurement. Develop plasma media that are suitable for the EO diagnostic development (prototype developed at Strathclyde) Improve stability of kHz Ti:sapphire laser to make it suitable for 0.1% plasma density measurements Use diagnostic system to measure plasma density and determine density to within 0.1% and determine the spatial resolution. Test EO TDS diagnostic system using the laser plasma wakefield accelerator at Strathclyde to determine temporal resolution AWAKE Oct. 2012SCAPA Beam diagnostic As for plasma: measurement based on THz EO-TDS Plasma density: direct spectroscopic method Electron bunch properties: transverse Coulomb field indirectly determined from induced electro-optic phase delays In AWAKE project: p + : 450 GeV, 12 cm e - : 5-20 MeV, 300fs-3 ps ( mm) bunching sub-ps length (Konstantin presentation yesterday) * Jamison,, Jarsozinsky, Opt. Lett. 31, 2006 AWAKE Oct. 2012SCAPA Beam diagnostic Basic scheme: Spectral decoding Temporal decoding AWAKE Oct. 2012SCAPA Beam diagnostic Not suitable for ultra short electron bunches (i.e.