group_5

Question 3:

Group chose a ¹⁵O + α reaction with SECAR.
Example_1.fox was edited to include a dipole which bends the trajectory 45°.
<PD> (corresponding to ΔE/E) in coordinate SB was changed to 0.01 to create a small momentum spread:

Question 4:

Used website to calculate θ_max and ΔE/E
- * Opening angle = 0.59 deg = 10 mrad which is less than the θ_max=25 mrad so we're good.
- * ΔE/E = (12.083-11.593)/(12.083+11.593) ~2% which is less than the 3.1% threshold so this also works.

Question 5:

Proton capture on ¹⁵O one might expect from rp-process conditions is halted by the short half-life of ¹⁶F (40 keV) and its proton emission back to ¹⁵O. The two minute half-life of ¹⁵O further acts to limit transitions out of ¹⁵O, making ¹⁵O a waiting point in nucleosynthesis in this mass region.
¹⁵O + α reaction plays a role in bypassing this waiting point in the ignition of type I x-ray bursts on accreting neutron stars, but the cross-section at relevant temperatures/energies has been experimentally inaccessible to date. The next generation recoil separators, St. George at Notre Dame and SECAR at NSCL/FRIB may reach sensitivity to this important reaction.

Question 6:

Using 'WRITE 6 VMAX(RAY(1))' x_max was calculated to be 0.2909704181068736E-002 m
Plotting COSY beam size (x) and the quadrupole field strength(divided by aperture radius) and arrived at the graph below. Data doesn't appear to fit the quadratic form too closely.
Calculated emittance is about 0.3 mm mrad, which is 50% larger than the 'real' emittance.

Question 7:

Effective field length of Q2 was increased by 3% and the drift lengths either side were adjusted accordingly, so as not to change the the centre position of the quadrupole.
The mass resolution was then optimised by minimising the function OBJ := 1/ABS(MRESOL_P1) by varying the strength of Q2, Q3 and Q4.
This would increase the mass resolution to values of up to 85,000, however the emittance was very large.

We realised that we should alter our objective function, in order to re focus our beam. This was achieved with the function OBJ := 1/ABS(MRESOL_P1) + ABS(ME(1,2)), where we added on the (a|x) matrix element to also minimise.

This optimisation improved the mass resolution from 640.86349 to 724.66207, while still focusing.

Question 8: