FISSION YIELD MEASUREMENTS WITH JYFLTRAP

FISSION YIELD MEASUREMENTS WITH JYFLTRAP Heikki Penttilä The IGISOL group University of Jyväskylä, Finland

Quick orientation Jyväskylä JYFLTRAP JYFL accelerator laboratory Me Spectrscopy line IGISOL-4 mass separator facility 18.12.214

The IGISOL-4 facility at JYFL IGISOL: Ion Guide Isotope Separator On-Line: a mass separator facility based on ion guide technique, capable making ion beams of any element IGISOL-1: c.a. 1981 1991 at MC2 proton cyclotron IGISOL-2 (1993 23) and IGISOL-3 (23 21) at K-13 IGISOL-4 moved/build next to new MCC3 light ion cyclotronin an extension experimental hall in 21-13 (still coupled to K-13). Commissioning 212 214 Facility can provide ultra pure beams of fission products Target SPIG Extractor electrode Fission yield (p-induced): 14 atoms/(mc * mbarn) Beam Al block Proton beam 3 MeV, 1 μa 9 Be target Cooling water

Fission ion guide technique Based on survival of primary ions from nuclear reaction in helium buffer gas Fast extraction of ions is required to prevent neutralisation Charge state concentration: (), +1, (+2) Produces ions of any element All elements can be studied All ions come directly from fission Ion rate in the formed beam corresponds to the independent fission yield Target Extractor SPIG electrode Beam 18.12.214

Fission ion guide technique Based on survival of primary ions from nuclear reaction in helium buffer gas Fast extraction of ions is required to prevent neutralisation Charge state concentration: (), +1, (+2) Produces ions of any element All elements can be studied All ions come directly from fission Ion rate in the formed beam corresponds to the independent fission yield 18.12.214

Isotopic purification with JYFLTRAP 18.12.214

Isotopic purification with JYFLTRAP Getting ion bunch from cooler in to the trap Gotcha! Ions are cooled and the cooled ions to a larger radius centers the chosen ones are dipole excited first Mass selective quadrupole excitation > 7 ms, typical 6 ms Finally, out of the trap they go namely, those that go 1.5 SPLAT

Isotopic purification with JYFLTRAP 1.5 SPLAT 18.12.214

From mass spectra to yield distribution 8 6 4 2 114 Rh Y 114 Pd 114 Ag A = 114 Y/Y r 1 Fit results for Pd c 2 =.36343 <A> = 114.8 ±.723 W = 2.886 ±.58443 Y = 1 ±.38865 Reference spectrum A = 115 8 8 6 Y r 115 Pd 115 Ag 6 4 2 115 Rh 115 Cd 4 2 12 1 8 116 Rh 116 Pd 116 Ag A = 116 6 18 11 112 114 116 118 4 2 x 1

Mass dependency of the stopped ions Simulations made by Uppsala Universitet collaboration http://arxiv.org/abs/149.714 18.12.214

Impact of stable isotope ions Space charge in the trap is an issue for yield measurements. Reduce amount of stable ions: - better purified system Lower ion rate: - ratio may kill yield anyway Pre-selection: - installing MR-TOF 18.12.214

Limits of resolving: overlapping isotopes Overlapping peaks can be resolved using gaussian fit Sufficient in this case uncertainty order of 1% 18.12.214

Even more challenging resolving by fit 18.12.214

Task for a fit master at limits of the first trap MRP (m/dm) = 2 currently the best the purification trap can do Higher MRP required for 132 Sn region and heaviest fragments (close to stability) Use of the second trap (precison trap) improves MRP by a factor of > 5 - Ramsey cleaning EPJA (212) 48:46 - PI ICR (Phase-Imaging Ion-Cyclotron- Resonance) PRL11,8251 (213) 18.12.214

Presenting the results 14 1 8 6 4 2 Fit results for Zr c 2 =.29137 <A> = 98.687 ± W = 2.7413 ±.5772 Y = 99.79 ± 3.3867 1 8 Rubchenya 6 4 Wahl (JEFF-UKFY4) 2 Fit results for Pd c 2 =.36343 <A> = 114.8 ±.723 W = 2.886 ±.58443 Y = 1 ±.38865 W 96 98 1 12 14 16 18 11 112 114 116 118 A max 18.12.214

25 MeV p + nat U fission : widths 1 Fit results for Pd c 2 =.36343 <A> = 114.8 ±.723 W = 2.886 ±.58443 Y = 1 ±.38865 8 6 4 2 W 18 11 112 114 116 118 Z

A UCD - <A> JYVÄSKYLÄN YLIOPISTO 25 MeV p + nat U fission : centroids A UCD = Z A(p+U) Z(p+U) Z

From isotopic yields to absolute yields? 14 1 Fit results for Br c 2 =.13871 <A> = 86.829 ±.694 W = 2.766 ±.1147 Y = 1 ± 4.6643 14 1 Fit results for Rb c 2 = 3.7498 <A> = 92.114 ±.46949 W = 2.6151 ±.56959 Y = 1 ± 4.6665 14 1 Fit results for In c 2 =.3896 <A> = 123.49 ±.7768 W = 2.6972 ±.63651 Y = 1 ± 1.3324 8 8 8 6 6 6 4 4 4 2 2 2 84 86 88 9 92 88 9 92 94 96 98 116 118 122 124 126 128 14 1 Fit results for Y c 2 = 1.519 <A> = 96.841 ±.82338 W = 2.778 ±.85224 Y = 1 ± 2.3414 14 1 Fit results for Pd c 2 =.36343 <A> = 114.8 ±.723 W = 2.886 ±.58443 Y = 1 ±.38865 14 1 Fit results for Ru c 2 = 1.5816 <A> = 19.59 ±.5538 W = 2.5371 ±.5741 Y = 1 ±.95159 8 8 8 6 6 6 4 4 4 2 2 2 9 92 94 96 98 1 12 18 11 112 114 116 118 14 16 18 11 112 114 18.12.214

Independent absolute yields? 14 1 Fit results for Br c 2 =.13871 <A> = 86.829 ±.694 W = 2.766 ±.1147 Y = 1 ± 4.6643 14 1 Fit results for Rb c 2 = 3.7498 <A> = 92.114 ±.46949 W = 2.6151 ±.56959 Y = 1 ± 4.6665 14 1 Fit results for In c 2 =.3896 <A> = 123.49 ±.7768 W = 2.6972 ±.63651 Y = 1 ± 1.3324 8 8 8 6 6 6 4 4 4 2 2 2 84 86 88 9 92 88 9 92 94 96 98 116 118 122 124 126 128 14 1 Fit results for Y c 2 = 1.519 <A> = 96.841 ±.82338 W = 2.778 ±.85224 Y = 1 ± 2.3414 14 1 Fit results for Pd c 2 =.36343 <A> = 114.8 ±.723 W = 2.886 ±.58443 Y = 1 ±.38865 14 1 Fit results for Ru c 2 = 1.5816 <A> = 19.59 ±.5538 W = 2.5371 ±.5741 Y = 1 ±.95159 8 8 8 6 6 6 4 4 4 2 2 2 9 92 94 96 98 1 12 18 11 112 114 116 118 14 16 18 11 112 114 6 Fission mass cross section Baba et al, / mb 4 2 25MeV p + 238 U Baba et al measured and reflected points Fit to Baba Isaev et al 26.5 MeV p + 238 U, fragments Complementary elements yields required equal 18.12.214 8 1 Mass number A 14 16

Future: neutron induced fission - concept Target chamber SPIG Cooling water He buffer gas 1 mm Be target Fission target 18.12.214

Neutron converter design Al block Proton beam 3 MeV, 1 μa M. Lantz, D. Gorelov et al., Phys. Scr. T15 (212) 142 9 Be target 18.12.214 Cooling water

Neutron converter flux test (March 214) NAA target positions 23 cm TFBC with 238 U target 18.12.214

IGISOL group and relevant collaboration: JYFL-IGISOL: H. Penttilä, A. Jokinen, I.D.Moore, J. Äystö, V.A. Rubchenya, S. Rinta-Antila, V. Kolhinen, T. Eronen, A. Kankainen, A. Voss, D. Gorelov, J. Hakala, V. Simutkin, V. Sonnenschein, I. Pohjalainen, J. Koponen, J. Reinikainen Uppsala University: A. Al-Adili, K. Jansson, M. Lantz, A. Solders, C. Gustavsson, A.Mattera, A. V. Prokofiev, V. Rakopoulos, D.Tarrío, S. Wiberg, M.Österlund, S. Pomp This work has been supported by Academy of Finland via several projects and the Centre of Excellence program, and by EU via ERINDA project (21-213) and will be supported by CHANDA project (213-217). 18.12.214