1. 1 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Positron Source Configuration KURIKI Masao and John Sheppard  BCD Description  Issues  Summary Powered by

2. 2 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. BCD Description -Concept- Positron is produced on the concept of high-energy photon conversion into e + e - pair in a thin rotating target. Photons are generated by the high energy electron beam through a long helical undulator. Positron is accelerated up to 250 MeV by NC copper cavities to employ the solenoid focusing. SC linac accelerates it up to 5 GeV.

3. 3 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. BCD Description -Layout- Primary e - source e - DR Target e - Dump Photon Beam Dump e + DR Auxiliary e - Source Photon Collimators Adiabatic Matching Device e + pre-accelerator ~5GeV 150 GeV100 GeV Helical Undulator In By-Pass Line Photon Target 250 GeV Positron Linac IP Beam Delivery System

4. 4 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. BCD Description  Undulator is placed at 150 GeV electron.  The length of unulator section is 100m (1 st phase) and 200m (2 nd phase).  Keep alive auxiliary source is defined as 10% of the nominal intensity.  There is a hot spare for the e+ station (rotating target and capture section) which can be switched remotely.

5. 5 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Issues (1) Design for the undulator section: Chicane, bend, or dog-leg? Lattice. Is the tunnel shared with the main linac or independent? e+ station: Do we need build each station in an isolated tunnel? (maybe, yes). Size of the tunnel? Do we need a full remote maintenance?

6. 6 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Issues (2)  e+ transport: 250 MeV is well optimized?  5GeV e+ linac: Where? In a separate or shared tunnel? If the tunnel is separate, what is the size of the tunnel?  e- source for the e+ arm Specifications (intensity, bunch structure, etc.) Where?

7. 7 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Issues (3)  Keep alive source: Where is the source? It should be in the e+ side. Specifications for the driver linac and the target.  Upgrade scenario: Do we need move the section at the upgrade? Is 400 GeV drive beam acceptable?  Spin rotator (option) : Do we need it at first? or later? Pulse by pulse or bunch by bunch? How long is the section?

8. 8 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Schedule  Jan. 31 : Define the basic layout and WBS. Estimation for the CF and cooling power.  Feb. 1~ : Contact all TGs.  Feb. 28 : List and count all parts.  June : e+ AG cost estimation.

9. 9 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Summary  Positron production for ILC is designed based on the undulator scheme in BCD.  There are many issues to be resolved to proceed further.  Especially, the basic tunnel layout and related subjects are the most important issues to make RDR.

10. 10 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Basic Parameters

11. 11 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Undulator Parameters

12. 12 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Target Parameters

13. 13 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Target Station The target is rotating with a velocity of 100m/s. A “hot spare” of target and capture system is included. The target is operated at half of the fatigue limit. The target life time is 1 year limited by radiation damage (can be longer). The target and capture system is implemented with a remote handling, but it is less difficult than that considered in SNS.

14. 14 Positron Source Configuration Masao KURIKI ILC AG meeting at KEK, 2006 Jan. Positron Injetor Linac PPA(Positron Pre Accelerator) : NC pre-accelerator, capture and accelerate the beam up to 250 MeV. Output beam :  E/E+-6%,  =+-7.5 o,  x,y <0.036m. First two cavities: 14.5MV/m, others : 8.5MV/m. Driven by 10MW TESLA klystron with 0.95ms duration, 5Hz. From the thermal stress analysis, 14.5 MV/m is possible. Magnetic insertion to reject electrons. A long transfer line below the IP. SC accelerator (338m), up to 5 GeV.