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22 Ne@131 MeV + 208 Pb: a PRISMA+CLARA data analysis

22 Ne@131 MeV + 208 Pb: a PRISMA+CLARA data analysis. Paolo Mason. Part 1 From raw data to mass spectra. PRISMA+CLARA: the set-up. Dipole. Quadrupole. Target. Ionization chamber [IC]. Start detector [MCP]. Focal plane [PPAC]. Rotating platform. PRISMA+CLARA: measured quantities.

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22 Ne@131 MeV + 208 Pb: a PRISMA+CLARA data analysis

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  1. 22Ne@131 MeV + 208Pb:a PRISMA+CLARA data analysis Paolo Mason

  2. Part 1From raw data to mass spectra

  3. PRISMA+CLARA: the set-up Dipole Quadrupole Target Ionization chamber [IC] Start detector [MCP] Focal plane [PPAC] Rotating platform

  4. PRISMA+CLARA: measured quantities • - Time of flight → directly involved in calculation of speed, therefore of • mass [mv2/R=qBv → m=qB•R/v] • Q-value • γ-ray energies (Doppler correction) • Entrance and focal-plane space coordinates → used to reconstruct • total distance D covered inside PRISMA (v = D/TOF) • trajectory’s curvature radius R in dipole magnet • Energy released in IC (each section) → used to select events (Z and q) • γ-rays→ (even when not of intrinsic interest, anyway) VERY useful to • check Z, A attributions • “calibrate” the TOF (Doppler correction) • understand Q-value spectra.

  5. The MCP (entrance) detector • Three signals of interest: • entrance X coordinate • entrance Y coordinate • TOF start • Actions: • noise removal • “calibration” of X,Y signals MCP Y [a.u.] MCP Y [a.u.] MCP X [arb. units] MCP X [arb. units] coincidence with some focal-plane signal

  6. Enhancing the focal-plane efficiencywith the cathode signal 1/2 Establishing link between values of Xfp determined with/without Scathode Removing cathode noise Sec. #3 Sec. #3 (Sleft+Sright)/2[a.u.] (Sright-Sleft)/4[a.u.] Scathode [arb. units] 1083 (Scathode-Sleft)/2[a.u.] 3141 Light ions produce weak signals which may be cut by CFD thresholds → Need to use the cathode signal when the left or right signal is not there 3000 987 Scathode/left/right = cathode/left/right signal

  7. Enhancing the focal-plane efficiencywith the cathode signal 2/2 Without cathode signal With cathode signal R/v [arb. units] R/v [arb. units] 0 1023 focal-plane X [mm] 0 1023 focal-plane X [mm]

  8. 2762 TOF [10-10 sec] arb. offsetS 1382 0 1023 2762 focal-plane X [mm] TOF [10-10 sec] arb. offset 1382 0 1023 focal-plane X [mm] Coarse matching of TOF offsets PPAC sections have different TOF offsets → need to match them …however, we may still have an arbitrary common TOF offset

  9. Bquadrupole/Bdipole optimization (Bq/Bd)1/2=0.99 R/v [arb. units] (Bq/Bd)1/2=0.96 (Bq/Bd)1/2=0.93 72 1013 129 458 focal-plane X [mm] Xfp [mm]

  10. TOF [10-10 sec] arb. offset D/R [arb. units] Fine matching of TOF offsets& removal of common TOF offset Cuts from Xfp vs R/v Counts R/v [arb. units] (*) (*) Also check Xfp-R/v plot: a nonzero common TOF offset warps the (supposed-to-be) straight horizontal traces.

  11. Mg Ne Na F O Energy release in IC [arb. units] Range in IC [arb. units] Z selection

  12. q=10+ q=9+ q=8+ Energy in IC [a.u.] 22Ne (must be) Z=10, qint=10 Neon DR/TOF [arb. units] Z=10, qint=9 counts Z=10, qint=8 17.59Ne ??? qintR/v [arb. units] qB selection - a first qR/v spectrum mv2/R = qBv → mv2/2 = 1/2 qB Rv m = qB R/v Must be more careful in selecting events

  13. Neon R/v [arb. units] Neon EIC/v2 [arb. units] Without (E/v2,R/v) bananas With (E/v2,R/v) bananas R/v [arb. units] Z=10, qint=10 Z=10, qint=9 counts Z=10, qint=8 EIC/v2 [arb. units] qintR/v [arb. units] qintR/v [arb. units] EIC/v2 vs R/v plots (E/v2,R/v) bananas give the possibility to remove spurious peaks. They may also serve as a tool to separate charge states.

  14. Z=12, qint=11 Z=11, qint=11 counts Z=11, qint=10 Z=12, qint=10 qintR/v [arb. units] Recognizing peaks - aligning R/v spectra R/v spectra corresponding to different charge states can be aligned just by a scaling (the scaling factor being, in principle, the charge). (1) A=23 from comparison with Z=10, qint=10 (*) spectrum (3) (2) A=23 from comparison with Z=11, qint=10 spectrum (3) A=26 from comparison with Z=11, qint=10,11 spectra (2) (1) (3) Once spectra corresponding to (common Z, but) different qint‘s are aligned, they can be summed and calibrated. (*) qint values are determined – comparatively – by looking at traces’ slopes in R•v vs EIC plot (**) If you find it downright outrageous to think of “fractional charges”, you might as well use integer scaling factors – along with nonzero offsets, though

  15. 3102 100 • mass [a.m.u.] 1424 0 1023 Xfp [mm] One last check: Xfp vs mass Neon FWHM/centroid = 9.8•10-3

  16. At last… mass yields A=26 Mg 101 103 A=23 Na 102 101 106 A=22 Ne 104 Counts 102 A=21 F 103 102 101 O A=20 102 101 Mass [a.m.u.]

  17. A brief summary • MCP detector: noise removal & “calibration” • PPAC detector: usage of cathode signal to enhance efficiency • Coarse matching of TOF offsets • Optimization of Bquad/Bdip & fine matching of TOF offsets + Removal of residual TOF common offset • Z selection • Charge-state selection from R•v-EIC , E/v2-R/v plots • Alignment of R/v spectra • Calibration of qR/v spectra → mass spectra • One needs not worry about scaling the TOF’s (to their “true” value) if he’s happy with mass spectra. • But to get γ-ray energies and Q-values right he has to.

  18. Part 2Gamma spectra

  19. Eγ= 777 keV 13 counts Eγ= 350 keV 45 counts Gammas in coincidence with Z=10, A=21 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  20. Eγ= 2613 keV 95 counts Eγ= 1275 keV 530 counts Eγ= 583 keV 149 counts Eγ= 509 keV 95 counts Gammas in coincidence with Z=10, A=22 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  21. Eγ= 1770 keV 29 counts Eγ= 1704 keV 22 counts Eγ= 1016 keV 98 counts Eγ= 898 keV 29 counts Eγ= 569 keV 321 counts Eγ= 492 keV 45 counts Gammas in coincidence with Z=10, A=23 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  22. Eγ= 2784 keV 6 counts Eγ= 1983 keV 42 counts Eγ= 881 keV 20 counts Eγ= 802 keV 80 counts Eγ= 537 keV 24 counts Gammas in coincidence with Z=10, A=24 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  23. Eγ= 440 keV 13 counts Eγ= 351 keV 10 counts Gammas in coincidence with Z=11, A=23 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  24. Eγ= 721 keV 4 counts Eγ= 204 keV 6 counts Gammas in coincidence with Z=11, A=25 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  25. Eγ= 656 keV 8 counts Eγ= 167 keV 7 counts Gammas in coincidence with Z=9, A=20 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  26. Eγ= 1606 keV 9 counts Eγ= 896 keV 20 counts Eγ= 822 keV 16 counts Eγ= 278 keV 26 counts Gammas in coincidence with Z=9, A=21 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  27. Eγ= 629 keV 6 counts Eγ= 245 keV 8 counts Gammas in coincidence with Z=8, A=20 EγDoppler correction with βtarget-like EγDoppler correction with βprojectile-like Level scheme from NNDC ENSDF database

  28. Part 3Q-values

  29. Mass vs Q-value - Z=12 -Q [MeV] Mass [a.m.u.] Mg A=25 26 27 28 -Q=-0.04 MeV 22Ne+208Pb→ AMg+229-AHg + n -3.6 -4.1 -4.8 -Q=-5.7 MeV 22Ne+208Pb→ AMg+230-AHg -10.1 -11.1 -12.6 Q-values from NNDC Q-value calculator

  30. Mass vs Q-value - Z=11 -Q value [MeV] Mass [a.m.u.] Na A=23 24 25 26 -Q=6.1 MeV 5.6 5.2 4.1 22Ne+208Pb→ ANa+229-ATl + n 22Ne+208Pb→ ANa+230-ATl -0.9 -Q=-0.8 MeV -1.4 -3.4 Q-values from NNDC Q-value calculator

  31. Mass vs Q-value - Z=10 -Q value [MeV] Mass [a.m.u.] Ne A=21 22 23 24 25 -Q=10.4 MeV 10.6 8.9 22Ne+208Pb→ ANe+229-APb + n 7.4 8.1 22Ne+208Pb→ ANe+230-APb -Q=6.4 MeV 3.9 2.2 0.04 0.0 Q-values from NNDC Q-value calculator

  32. Mass vs Q-value - Z=9 -Q value [MeV] Mass [a.m.u.] F A=19 20 21 22 23 -Q=21.6 MeV 21.1 20.6 22Ne+208Pb→ AF+229-ABi + n 19.6 18.9 22Ne+208Pb→ AF+230-ABi -Q=16.4 MeV 15.0 13.7 13.0 11.5 Q-values from NNDC Q-value calculator

  33. Mass vs Q-value - Z=8 -Q value [MeV] Mass [a.m.u.] O A=17 18 19 20 21 22 30.0 -Q=26.7 MeV 28.4 22Ne+208Pb→ AO+229-APo + n 25.2 25.3 24.6 22Ne+208Pb→ AO+230-APo -Q=22.3 MeV 21.5 21.6 20.7 18.6 17.6 Q-values from NNDC Q-value calculator

  34. Eγ=1968 keV Eγ [keV] target-like Doppler Eγ= 629 keV 210Po 8+→8+ Eγ= 245 keV 210Po 4+→2+ Eγ=0 keV -Q=13.0 MeV -Q=28.5 MeV -Q [MeV] Q-value vs Gammas - Z=8, A=20 selection Eγ=1968 keV 32 counts 29 counts Eγ [keV] target-like Doppler Eγ=0 keV -Q=7.5 MeV -Q=25.3 MeV -Q=53 MeV -Q value [MeV] 22Ne+208Pb →20O+209Po+n corresponds to Q-value = -25.3 MeV [NNDC]

  35. Selection: Z=10, A=23 23Ne 206Pb 2+→0+ 803 keV 23Ne -Q ≥ 9.5 MeV 206Pb counts 207Pb 5/2-→1/2- 570 keV -2.0 ≤ -Q ≤ 9.0 MeV 1n pick-up 2n pick-up 207Pb 3/2-→1/2- 898 keV 207Pb 7/2-→5/2- 1770 keV 206Pb Eγ [keV] target-like Doppler Signature of one-neutron evaporation following one- or two-neutron pick-up 22Ne+208Pb →23Ne+206Po+n corresponds to Q-value = -8.9 MeV [NNDC]

  36. Coincidence with CLARA 102 101 104 counts 102 Maximal EIC 103 101 Q-value [MeV] -15 -10 -5 0 5 10 15 20 25 30 35 40 45 207Pb 5/2-→1/2- 570 keV 7.5 ≤ -Q ≤ 36.0 MeV 208Pb 511 keV 3.5 ≤ -Q ≤ 7.0 MeV 208Pb 51-→3- 583 keV 208Pb 583 keV counts counts 208Pb 52-→51- 511 keV 208Pb 3-→0+ 2615 keV -3.5 ≤ -Q ≤ 1.0 MeV 22Ne 2+→0+ wrong Doppler Eγ [keV] target-like Doppler Eγ [keV] Understanding the Q-value spectrum in coincidence with the detection of 22Ne 22Ne+208Pb →22Ne+207Pb+n corresponds to Q-value = -7.4 MeV [NNDC]

  37. Thank Nicu for • training • additional programming • standing the hassle that I gave to him The end

  38. 23Ne 23Ne 206Pb 1n pick-up 2n pick-up 206Pb

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