1. m.apollonioam0412071 M. Apollonio University of Oxford update on STEP III

2. m.apollonioam0412072 the case for STAGE III first demonstration of cooling with solid absorber(s) ?

3. m.apollonioam0412073 Matching Coils currents Set up a procedure to find the right MC currents for a matched beam: a)  (trk1-2)=1/ ,  =0 b) fix  (min) Z (m) Chosen configuration must comply with coil/physics constraints: 1- max current 2- temp. margin 3-  (min)  minimise m.s. B (T)  (m)

4. m.apollonioam0412074 800 mm

5. m.apollonioam0412075 800 mm T=97.9 % T=98.4 % emi=10 mm rad (a)(b) (a) (b)

6. m.apollonioam0412076 NB: beta_min = 49 cm (was 60cm at CM14) means M1 1.4x, M2 0.7x main issues a)current increase: is it within tolereances? b)magnet forces? c)MC distance = 800 mm. Can it be changed? 300 A!

7. m.apollonioam0412077 emittance growth in vacuum Z (m)  T (final)/  T (initial)  i =1.0 cm rad 0 1 2 3 4 5 6  T /  T =2.8% 2.8 %  T /  T Z (m)  T (cm rad)

8. m.apollonioam0412078 : emittance evolution in a cylindrical symmetric channel non uniform B z can cause  growth (e.g. flip region) Z (m)  T (m rad) ecalc9 MUC-NOTE 0071 prediction Most of the effect explained

9. m.apollonioam0412079 (a) 13 cm LiH absorber in the middle

10. m.apollonioam04120710 -7.3% -3% Pz vs Z emi vs Z Beta= 70cm Beta= 50 cm

11. m.apollonioam04120711 (b) 13 cm LiH absorber in the II solenoid

12. m.apollonioam04120712 vacuum (no absorbers) LiH absorber LiH absorber - vacuum

13. m.apollonioam04120713 equilibrium vacuum growth subtracted emi. % variation

14. m.apollonioam04120714

15. m.apollonioam04120715 Conclusion 1)Slow B flip  emi growth. Has to be minimized 2)a single absorber seems to work better 3) the middle point cannot have a low beta  cooling effect reduced 4) reduce beta_centre  increase M1 currents  forces 5) better to place abs inside the II solenoid  uneasy 6) transmission: large radius spool piece doesn’t seem to create dramatic effects