1. CesrTA Low Emittance Program for Electron Cloud Studies Dan Gonnella Advisors: David Rubin, Mark Palmer Cornell University Laboratory for Elementary-Particle Physics

2. June 19, 2009 Dan Gonnella 2 Outline Project Overview Steps in the Process Theoretical Computations Why it’s Important Plans for the Future

3. Project Overview GOAL: To understand the relationship between: –Beam Lifetime (Related to the touschek parameter) –Beam Emittance (Size of the beam) –Bunch Charge –Beam Energy June 19, 2009 Cornell LEPP Template 3

4. Project Goals Currently, the goal has been to re-create a plot of the Accelerating Voltage vs. the Touschek Parameter (inverse-lifetime). June 19, 2009 Cornell LEPP Template 4

5. Steps in the Process Generate/analyze data from a lattice file and bmad/fortran program that does NOT include intrabeam scattering. Generate/analyze data that does include intrabeam scattering. The lattice file defines the energy, zero current emittances, damping times, energy spread, etc. Using a lattice file for 2.085 GeV June 19, 2009 Cornell LEPP Template 5

6. Theoretical Computations Output 20 sets of data for a given accelerating voltage and dynamic acceptance. Fit data to the equation: June 19, 2009 Cornell LEPP Template 6

7. Experimental Data We cam fit experimentally obtained data at different voltages to obtain the touschek parameter. Data taken in the machine last Friday (6/12) at approximately 5 MV showed a touschek parameter of 0.800. June 19, 2009 Cornell LEPP Template 7

8. Final Data June 19, 2009 Cornell LEPP Template 8 Intrabeam scattering occurs when particles in the beam collide with one another. It generally causes the beam size to grow and thus raise the emittance.

9. Why it’s Important Low emittance operation is essential for the ILC research being done through the CesrTA project. Ultra-low emittance means a higher particle density in the beam. Higher particle density causes more particles to interact when collisions take place, resulting in higher luminosity. June 19, 2009 Cornell LEPP Template 9

10. Side by Side Comparison June 19, 2009 Cornell LEPP Template 10

11. Plans for the Future Troubleshoot the program so the plot more closely matches the previously obtained plot. Try to match the experimentally obtained touschek parameter to a theoretical emittance and dynamic acceptance. This will allow us to understand more about the machine since we currently do not have a means of accurately measuring the emittance. June 19, 2009 Cornell LEPP Template 11

12. Questions? June 19, 2009 Cornell LEPP Template 12