Andriy Ushakov

Heat Load and Stress Studies for an Design of the Photon Collimator for the ILC Positron Source

The ILC baseline design for the positron source is based on radiation from a helical undulator to produce positrons in a thin target. Since the photon beam created in the helical undulator is circularly polarized, the generated positron beam is longitudinally polarized. Using a photon collimator upstream the positron target the positron polarization can be enhanced. However, the photon beam intensity yields a huge thermal load in the collimator material. In this paper the thermal load and heat dissipation in the photon collimator is discussed and design solutions are suggested.

A conventional positron source for international linear collider

A possible solution to realize a conventional positron source driven by a several-GeV electron beam for the International Linear Collider is proposed. A 300 Hz electron linac is employed to create positrons with stretching pulse length in order to cure target thermal load. ILC requires about 2600 bunches in a train which pulse length is 1 ms. Each pulse of the 300 Hz linac creates about 130 bunches, then 2600 bunches are created in 63 ms. Optimized parameters such as drive beam energy, beam size, and target thickness, are discussed assuming a L-band capture system to maximize the capture efficiency and to mitigate the target thermal load. A slow rotating tungsten disk is employed as positron generation target

Polarized positrons for the ILC - update on simulations

To achieve the extremely high luminosity for colliding electron-positron beams at the future International Linear Collider (ILC) an undulator-based source with about 230 meters helical undulator and a thin titanium-alloy target rim rotated with tangential velocity of about 100 meters per second are foreseen. The very high density of heat deposited in the target has to be analyzed carefully. The energy deposited by the photon beam in the target has been calculated in FLUKA. The resulting stress in the target material after one bunch train has been simulated in ANSYS.

Polarized Positrons for Future Linear Colliders

The high luminosity requirements and the option of a polarized beam present a great challenge for the design of the positron source for future linear colliders. This contribution provides an overview of the proposed designs for the polarized positron sources of the International Linear Collider (ILC) and the Compact Linear Collider (CLIC).

Design and optimization of a polarized positron source for future linear collider using Geant4

A polarized positron source is one of the key ingredients of a future linear collider. The source performance is decisive in order to reach the goals of the physics programme. But it is a challenge to develop a high-intensity polarized positron source, which meets the machine requirements. Simulation programs which can calculate expected yield, polarization are indispensable tools in these R&D projects. Based on the Geant4 framework a new tool, PPS-Sim (Polarized Positron Source Simulation), has been developed for design and optimization of a polarized positron source. This program is able to simulate common positron production mechanisms. It describes both the production of polarized positrons, and the spin transport in electromagnetic components in a single framework.