Paper |
Title |
Page |
TOAD004 |
The Possibility of Noninvasive Micron High Energy Electron Beam Size Measurement Using Diffraction Radiation
|
404 |
|
- G.A. Naumenko, A. Potylitsyn
Tomsk Polytechnic University, Physical-Technical Department, Tomsk
- S. Araki, A. Aryshev, H. Hayano, V. Karataev, T. Muto, J.U. Urakawa
KEK, Ibaraki
- D. Cline, Y. Fukui
UCLA, Los Angeles, California
- R. Hamatsu
TMU, Hatioji-shi,Tokyo
- M.C. Ross
SLAC, Menlo Park, California
|
|
|
During the last years a noninvasive method for beam size measurement based on the optical diffraction radiation (ODR) has been in progress (P. Karataev, et al., Physical Review Letters 93, 244802 (2004). However this technique encounters with hard sensitivity limitation for electron energies larger than several GeV. For example, for SLAC conditions the sensitivity of this method is 4 orders smaller than an appropriate one. We suggest to use a "dis-phased" slit target, where two semi-planes are turned with respect to each other at a small "dis-phased" angle. In order to ensure the interference between the diverged radiation beams we use a cylindrical lens. This method has much better sensitivity and resolution. A "dis-phased" angle 10 milliradians gives the optimal sensitivity to 5 microns transversal beam size. The theoretical model for calculating the ODR radiation from such targets (including focusing by cylindrical lens) is presented. It is shown that the sensitivity of this method does not depend on the Lorenz-factor directly. The target with the "dis-phased" angle 6.2 milliradians and the slit width 425 microns was manufactured for experimental test. Some preliminary experimental results are presented.
|
|
RPAT077 |
Beam Test Proposal of an ODR Beam Size Monitor at the SLAC FFTB
|
4015 |
|
- Y. Fukui, D. Cline, F. Zhou
UCLA, Los Angeles, California
- A. Aryshev, V. Karataev, T. Muto, M. Tobiyama, J.U. Urakawa
KEK, Ibaraki
- P.R. Bolton, M.C. Ross
SLAC, Menlo Park, California
- R. Hamatsu
TMU, Hatioji-shi,Tokyo
- G.A. Naumenko, A. Potylitsyn, A. Sharafutdinov
Tomsk Polytechnic University, Physical-Technical Department, Tomsk
|
|
|
We design a single bunch transverse beam size monitor which will be tested to measure the 29 GeV electron/positron beam at the SLAC FFTB beam line.The beam size monitor uses a CCD camera to make images of the interference pattern of the optical diffraction radiation from conductive slit target which are placed close to the beam path. In this method, destruction of the accelerated electron/positron beam bunches due to the beam size monitoring is negligible, which is vital to the operation of the Linear Collider project. A dis-phased conductive slit target and a lens system allow us to recover the sensitivity of the transverse beam size with a small photon yield ratio at the valley to that at the peak due to the large gamma*λ, and with the near field effect due to the large λ*gamma**2. A solution for non-negligible divergence at the SLAC FFTB is also discussed.
|
|