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ATF2 ultra-low betas and even more chromatic proposals R. Toms, S. - PowerPoint PPT Presentation

ATF2 ultra-low betas and even more chromatic proposals R. Toms, S. Bai, P. Bambade, Y. Kamiya, S. Kuroda, Y. Renier, A. Seryi and G. White Thanks to H. Braun, A. Jeremie, A. Latina, D. Schulte, F. Zimmermann et al ATF2 collaboration meeting,


  1. ATF2 ultra-low betas and even more chromatic proposals R. Tomás, S. Bai, P. Bambade, Y. Kamiya, S. Kuroda, Y. Renier, A. Seryi and G. White Thanks to H. Braun, A. Jeremie, A. Latina, D. Schulte, F. Zimmermann et al ATF2 collaboration meeting, 2008 Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.1/29

  2. FFS problematics Problem Scales with E 3 Radiation L ∗ /β ∗ Chromaticity ( ξ y ) Imperfections, 1 /σ ∗ ? tuning time Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.2/29

  3. Chromaticity L ∗ [m] β ∗ L ∗ / β ∗ ξ y Project Status y [mm] y FFTB Measured 0.167 0.4 2400 10000 ATF2 Design 0.1 1.0 10000 19000 ATF2 ultra-low β Proposed 0.025 1.0 40000 76000 CLIC 3TeV Design 0.09 3.5 39000 63000 Proposed † CLIC long L* 0.1 8 80000 120000 ILC Design 0.4 3.5 8750 15000 ILC pushed Design 0.2 3.5 17500 30000 † Proposed by A. Seryi in CLIC08 Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.3/29

  4. CLIC FFS, 3.5m versus 4.3m L* 1 Peak luminosity (relative) 0.8 0.6 0.4 L * =3.5m 0.2 L * =3.5m (opt.) L * =4.3m 0 -0.01 -0.005 0 0.005 0.01 dp/p → Larger peak-lumi-bandwidth for the 3.5m L* FFS Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.4/29

  5. IP spot size: tuning σ ∗ Project Status y [nm] FFTB Measured 70 ATF2 Design 37 ATF2 ultra-low β Proposed 20 ILC Design 6 CLIC Design 2 Does tuning difficulty scale as σ ∗ − 1 ? y ATF2 offers the unique opportunity to study tuning versus σ ∗ y . Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.5/29

  6. ATF2 ultra-low β proposal ��������������������������������������� ��������������������������� � � � � � � � � � � � � �� � ������ ����� ��� � �� ������� � � ��� ����� � ��������� � ��� � � ���� �� � ��� �� � � ������� � ��� �������� � ��� � ����������� � ������� � �� ������� ! ���������" � ��� ������� ���� ����� �� �� ����� �� �� �� � ! ���#��$%��� ! �� ��&����� � ������'� � ������'���)� � ���������� * ��#��#� �'�� ! ��&��#�� ��, ��������� �(� + " ��� ! �����/� � ��0��/��)� ��* ��0��/������ * ��1�/��2�� � ��3��2�� � � � ���-�� %� .� �� � ��� � �� � � � �4 � 56 &��76 ����8�8��$�"� ���3�� �'�� �4 � 7�9������:�����5���� � �4 � 59&6 ������;� ���.�)<���� ��� !4 � �9���#"�%��� ���� =� �� *4 � �8�5���)� �(�����-��� �4 � 5�'%'��()�7�")�)�)����� �� "������-�� � � � ��� ���� �� � ����� ��� �� �!�� ��� �" #���� �$�� ����� !%&�!� ��'� ��(�������� �(� �$�� ��)�� )%��#� )���!� *+!����(�����'���'��,������(����%��!�� ������(���������-��������'�.���#�-�%�!�'�!%/�0��$�� ��!�#�!�-%##�'����!�������$��(��!%�%#%�+��(��$��!+!����%�����$�����%�%�+���/%����(�%�����!��(��� �������'����0� � � � � � � 1 ������! ��'%�/����$��2���/�#%�0����!3����0�$ Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.6/29 � ������

  7. ATF2 β ∗ scan (S. Bai) V a ria b le A T F 2 b e a m s iz e sig y (lo g s c a le ) 9 7 8 7 7 7 6 7 5 7 n o m in a l b e tx 4 7 h a lf b e tx 3 7 2 7 cacacacac •← MAPCLASS optimization cacacacac s q rt(b e ty*e p sy ) 1 7 0 .0 0 0 0 0 .0 0 0 2 0 .0 0 0 4 0 .0 0 0 6 0 .0 0 0 8 b e ty n o m in a l /4 b e ty So far the minimum ATF2 σ ∗ y =20nm Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.7/29

  8. Tuning simulations • Realistic alignment and field errors are assigned to the ideal model • Tuning algorithm is the Simplex having: variables:x, y, roll and magnet strength observables:Luminosity (CLIC) or beam sizes (ATF2) • Ground motion is included in the simulation • γǫ x = 3 µ m, ǫ x = 1 . 2 nm Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.8/29

  9. ATF2 ultra-low β tuning example ATF2 ultra-low β y tuning example (Simplex) IP beam sizes [ µ m] 1 0.1 vert. Gauss vert. rms hor. Gauss hor. rms targets 0.01 0 500 1000 1500 2000 2500 3000 3500 4000 Iteration number (1 iteration=1 minute) Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.9/29

  10. CLIC tuning: 100 perturbed machines 9 8 7 6 Counts 5 4 3 2 1 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Initial σ y [ µ m] Initial CLIC beam sizes up to 4 µ m (to be tuned down to 1nm). Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.10/29

  11. Luminosity after tuning 14 12 10 8 Counts 6 4 2 0 0.6 0.8 1 1.2 Relative final luminosity [L 0 ] 20% of the cases below 80% of the target luminosity! Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.11/29

  12. How to fix this? • Join the ATF2 collaboration Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.12/29

  13. ATF Initial σ y for 150 seeds 16 14 12 10 Counts 8 6 4 2 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Initial σ y [ µ m] Up to 4 µ m of initial σ y (same as CLIC!). Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.13/29

  14. ATF2 β ∗ y =0.025mm 40 35 Gaussian σ y [nm] 30 25 20 15 10 10 15 20 25 30 35 40 RMS σ y [nm] Rising discrepancy between rms and Gaussian fit, what does the Shintake monitor do? Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.14/29

  15. Rogelio ATF2 β ∗ Tom´ as Garc´ 29th Oct. 2008 ATF2 Weekly meeting 9/16 Measured size is between the core size and The larger deviation cause bigger difference ıa 10 10 beam proÞle 10 1 2 3 -65.1 y =0.025: Shintake monitor -65 For beams with larger deviation from Gaussian made by Rogelio the RMS size -64.9 23.7 nm (core beam size) -64.8 -64.7 -64.6 y (micron) -64.5 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 27.7 nm (measured) entries xxxx xxxx xxxx xxxx xxxx xxxx 10 xxxx xxxx 0 2 4 6 8 xxxx xxxx xxxx xxxx 18 xxxx xxxx xxxx xxxx xxxx xxxx ATF2 xxxx xxxx xxxx xxxx 20 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 22 xxxx ultra-low xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 24 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 26 xxxx xxxx xxxx betas xxxx xxxx xxxx xxxx xxxx 29.8 nm (RMS beam size) xxxx xxxx 28 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx and xxxx xxxx Y. Kamiya xxxx 30 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx even xxxx xxxx 32 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 34 xxxx xxxx more xxxx xxxx xxxx beam size (nm) xxxx xxxx xxxx xxxx xxxx 36 xxxx xxxx xxxx xxxx xxxx xxxx chromatic xxxx xxxx xxxx xxxx xxxx 38 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx proposals – p.15/29

  16. Final spot size for β y =0.025mm 35 30 25 20 Counts 15 10 5 0 20 25 30 35 40 45 50 55 60 Final σ y [nm] Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.16/29

  17. Success versus time, β y =0.025mm 90 80 70 60 Efficiency [%] 50 40 30 20 10 0 0 2000 4000 6000 8000 10000 12000 14000 Number of iterations Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.17/29

  18. Summary table case Max. tuning time Ratio of success β y =0.1mm 5.5 days 100% β y =0.05mm 8 days 90% β y =0.025mm 10 days 80% Tuning time roughly scales with β − 2 or σ − 1 y y Rogelio Tom´ as Garc´ ıa ATF2 ultra-low betas and even more chromatic proposals – p.18/29

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