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group_secar2.0 [2018/09/10 15:50] plastun |
group_secar2.0 [2018/09/11 17:23] wagner [Emittance Measurement] |
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- | Group SECAR2.0 | + | ====== |
- | Reaction: < | + | -- by Alex, Nadeesha and Louis -- |
+ | |||
+ | ===== DAY1===== | ||
+ | ==== Getting started ===== | ||
+ | |||
+ | Choosen example reaction: < | ||
+ | ⇒important for < | ||
Beam: < | Beam: < | ||
{{ : | {{ : | ||
- | Matrix:\\ | + | ====Understanding COSY Matrix |
- | | 1.0|0.0|0.0|0.0|-0.41 | | + | Command: OV 1 1 0 ; {order 1, phase space dim 1 INCLUDING ENERGY, # of parameters 0}\\ |
- | | 2.2|1.0|0.0|0.0|-0.35 |\\ | + | Output:\\ |
+ | |1.0|0.0|0.0|0.0|-0.41| | ||
+ | |2.2|1.0|0.0|0.0|-0.35|\\ | ||
+ | Explanation: | ||
+ | |R< | ||
+ | |R< | ||
R< | R< | ||
R< | R< | ||
Line 14: | Line 25: | ||
R< | R< | ||
+ | ==== Reaction Kinematics Calculation==== | ||
{{ : | {{ : | ||
- | Reaction summary for 45V+p→γ+46Cr, Ek(45V)=135 MeV\\ | + | |
+ | Reaction summary for < | ||
The maximum γ energy is 8.481 MeV. The minimum γ energy is 7.249 MeV.\\ | The maximum γ energy is 8.481 MeV. The minimum γ energy is 7.249 MeV.\\ | ||
- | The maximum | + | The maximum |
- | SB 0.1 0.00226 0 0.1 0.00226 0 0 0.0047 0 0 0 ;\\ | + | |
- | [[Test|Test]] | + | If we assume a normalized emittance of 0.6 π mm mrad provided from ReA3 at 3.0 MeV/u the geometric emittance is 0.6/0.08 = 7.5 π mm mrad.\\ |
+ | With the spot size on the target, designed to be ±0.5 mm (1σ), the anglular spread then is ±15 mrad.\\ | ||
+ | Adding the calculated spread from the reaction with the target of 0.13 deg = ±2.26 mrad we get ±17.26 mrad of angular spread.\\ | ||
+ | ⇒COSY beam input: SB 0.0005 **0.01726** 0 0.0005 **0.01726** | ||
+ | Output for this beam passing the dipole: | ||
+ | {{ : | ||
+ | |||
+ | ===== DAY2 ===== | ||
+ | |||
+ | ==== Emittance Measurement ==== | ||
+ | |||
+ | The distance between the center of Q7 and the focal plane FP2 is 6.085 m as extracted from the script file. | ||
+ | {{ : | ||
+ | |||
+ | === Quadrupole strenght variations for emittance measurment === | ||
+ | |||
+ | |B< | ||
+ | |0.02 |2.91E-03 |0.13 |0.8 |6.085 |0.065384615| | ||
+ | |0.01 |2.27E-03 |0.13 |0.8 |6.085 |0.032692308| | ||
+ | |0 |1.62E-03 |0.13 |0.8 |6.085 |0| | ||
+ | |-0.01 |1.20E-03 |0.13 |0.8 |6.085 |-0.032692308| | ||
+ | |-0.02 |9.08E-04 |0.13 |0.8 |6.085 |-0.065384615| | ||
+ | |-0.03 |6.23E-04 |0.13 |0.8 |6.085 |-0.098076923| | ||
+ | |-0.04 |9.54E-04 |0.13 |0.8 |6.085 |-0.130769231| | ||
+ | |-0.05 |1.60E-03 |0.13 |0.8 |6.085 |-0.163461538| | ||
+ | |-0.06 |2.26E-03 |0.13 |0.8 |6.085 |-0.196153846|\\ | ||
+ | |||
+ | *Bρ the magnetic rigidity was extracted from COSY by comand CONS(CHIM)\\ | ||
+ | |||
+ | === Fit of the data to parabola === | ||
+ | |||
+ | {{ : | ||
+ | |||
+ | Fit result for parabola X< | ||
+ | |||
+ | a = 0.000362572706 \\ | ||
+ | b = 0.0834414129893 \\ | ||
+ | c = 3.506973286e-07\\ | ||
+ | |||
+ | The consistency check for beam size calculation in Q7 shows:\\ | ||
+ | X_calculated = 3.13mm, X_cosy_read_out = 3.16mm at the Q7 exit.\\ | ||
+ | Emittance calculated from fit parameters ε= √(ac) / L< | ||
+ | Start beam emittance= XX · AX= 0.2 π mm mrad, so the emittance grows from the start to the focal point.\\ | ||
+ | This emittance grow is possibly due to the optics aberrations. That is because the input COSY file does a 4th-order-calculation. Also the measured points don't fit the parabola ideally, i.e. the optics is non-linear.\\ | ||
+ |