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Jansson, A.

Paper Title Page
RPAT032 An Ionization Profile Monitor for the Tevatron 2227
 
  • A. Jansson, M. Bowden, K. Bowie, A. Bross, R. Dysert, T. Fitzpatrick, R. Kwarciany, C. Lundberg, H. Nguyen, C.H. Rivetta, D. Slimmer, L. Valerio, J.R. Zagel
    Fermilab, Batavia, Illinois
 
  Funding: Work supported by the U.S. Department of Energy.

Primarily to study emittance blowup during injection and ramping, an ionization profile monitor has been developed for the Tevatron. It is based on a prototype installed in the Main Injector, although with extensive modifications. In particular, the electromagnetic shielding has been improved, the signal path has been cleaned up, and provisions have been made for an internal electron source. Due to the good Tevatron vacuum, a local pressure bump is introduced to increase the primary signal, which is then amplified by a microchannel plate and detected on anode strips. For the DAQ, a custom ASIC developed for the CMS experiment is used. It is a combined charge integrator and digitizer, with a sensitivity of a few fC, and a time-resolution that allows single bunch measurement. Digitization is done in the tunnel to reduce noise. Preparations for detector installation were made during the long 2004 shutdown, with the installation of magnets, vacuum chambers, vacuum pumps and cabling. The actual detector will be installed sometime during the spring fo 2005. This paper describes the design of the detector and associated electronics and presents various bench test results.

 
RPAT033 Beta Function Measurement in the Tevatron Using Quadrupole Gradient Modulation 2272
 
  • A. Jansson, P. Lebrun, J.T. Volk
    Fermilab, Batavia, Illinois
 
  Funding: Work supported by the U.S. Department of Energy.

Early in Run2, there was an effort to compare the different emittance measurements in the Tevatron (flying wires and synchtotron light) and understand the origin of the observed differences. To measure the beta function at a few key locations near the instruments, air-core quadrupoles were installed. By modulating the gradient of these magents and measuring the effect on the tune, the lattice parameters can be extracted. Initially, the results seem to disagree with with other methods. At the time, the lattice was strongly coupled due to a skew component in the main dipoles, caused by sagging of the cryostat. After a large fraction of the superconducting magnets were shimmed to remove a strong skew quadrupole component, the results now agree with expectations, confirming that the beta function is not the major error source of discrepancy in the emittance measurement.