270 likes | 490 Views
RITU and the new separator at Jyväskylä J. Uusitalo, J. Sarén, M. Leino RITU and γ-groups University of Jyväskylä, Department of Physics. RITU, Recoil Ion Transport Unit. Magnetic configuration Q v DQ h Q v Maximum beam rigidity 2.2Tm Bending radius 1.85 m Angular acceptance 8 msr
E N D
RITU and the new separator at Jyväskylä J. Uusitalo, J. Sarén, M. Leino RITU and γ-groups University of Jyväskylä, Department of Physics
RITU, Recoil Ion Transport Unit • Magnetic configuration QvDQhQv • Maximum beam rigidity 2.2Tm • Bending radius 1.85 m • Angular acceptance 8 msr • - measured with alpha source • Dispersion 10 mm/% of Bρ • Dipole bending angle 25o • - Total length 4.8 m
40Ar + 175Lu —> 211Ac + 4n Efr = 33 MeV qave = 6.9 vert. acc. ± 26 mrad horiz. acc. ± 77 mrad Acceptance 8 msr
JUROGAM GREAT RITU
Nuclear Physics Group at Daresbury, University of Liverpool, Manchester University, University of Surrey, York University, Keele University MWPC PIN-diodes DSSSD Planar Ge Clover Ge TDR acquisition system
The GREAT detector system 2x 60mm x 40mm DSSD 28x 40mm x 40mm PIN Segmented planar Ge Compton-suppressed Ge clover Gas counters U.K. Universities & Daresbury Triggerless TDR DAQ system Presently at JYFL
A gas-filled recoil separator plan NIMB 204, 138 (2003) T. Enqvist et.al., 112Sn(86Kr, 3n)195Rn @ 365 MeV 0, ± 26 mrad, 0, ± 1mm Dispersion 15 mm/%Bρ
if Bρ difference 4 % between 195Rn and beam 86Kr, and ± 7 mrad for beam and ± 26 mrad for 195Rn RITU QDQQ with 25o dipole magnet DQQ with 50o dipole magnet DQQ with 50o dipole magnet, and Bn = -4
The new JYFL vacuum mode separator Design, ion optics and Physics Matti Leino, Jan Sarén, Juha Uusitalo, RITU and GAMMA groups
Charged particle in electric and magnetic fields Magnetic rigidity: Electric rigidity: Resolving power: Deflection angles in electric field: Universal: - Both electric and dipole fields are needed - Beam is dumped inside the first dipole (chamber) - Mass resolving power about 350 FWHM can be reached - Full energy beam suppression factor of 109-1015 can be expected
Mass separators all around the world: some trends DRS: Q1-Q2-Q3-WF1-WF2-Q4-Q5- Q6-S1-S2-MD1-Q7-Q8-Q9 (13.0 m) CARP: Q1-MD1-H1-H2-ED1-H3-Q2 CAMEL: Q1-Q2-ED1-S1-MD1-S2-ED2 HIRA: Q1-Q2-ED1-M1-MD1-ED2-Q3-Q4 (8.6 m) JAERI-RMS: Q1-Q2-ED1-MD1-ED2-Q3-Q4-O1 (9.4 m) FMA: Q1-Q2-ED1-MD1-ED2-Q3-Q4 (8.2 m) EMMA: Q1-Q2-ED1-MD1-ED2-Q3-Q4 (9.04 m) JYFL new: Q1-Q2-Q3-ED1-MD1 (6.74 m) Q quadrupole S sextupole H hexapole M multipole O octupole WF velocity filter ED electric dipole MD magnetic dipole
Design principles and aberrations - Maximizing angular, mass and energy acceptance while minimizing geometric and chromatic aberrations. - The largest aberrations are (x|δ2), (x|θδ) and (x|θ2). These are minimized by adding a curvature to the magnetic dipole entrance and exit. - Higher order aberrations found to be negligible.
Angular focus in x- and y-directions X-direction, 5 angles: 0, ±15 and ±30 mrad Y-direction, 5 angles: 0, ±20 and ±40 mrad
Energy focus and mass dispersion in x-direction Energy deviation: 0, ±3.5 and 7.0 % 3 different angles 3 different energies 3 different masses Angles: 0 and ±30 mrad, Masses: 0 and ±1 % Energies: 0 and 7.0 %
Main properties of the new separator compared to FMA • FMAJYFL new • - Configuration QQEDMDEDQQ QQQEDMD • - Horizontal magnification -1.93 -1.58 • - Vertical magnification 0.98 -4.48 • - M/Q dispersion -10.0 mm/% 8.1 mm/% • - First order resolving power, 259 256 • 2 mm beam spot • Solid angle acceptance 8 msr 10 msr • - Energy acceptance for • central mass and angle +20 % - 15 % +20 % - 15 % • - M/Q acceptance 4 % 7 %
What kind of research work can be done were RITU separator is not feasible Probing the N Z line up to 112Ba - decay spectroscopy (proton and -particle decay) at the 100Sn region - rp-process - proton-neutron pairing interaction - mirror nuclei o study of isospin symmetry breaking o proton skins (N < Z nuclei) D. Joss - superdeformation and hyperdeformation (N Z 40) Methods - focal plane detector system: o DSSSD, position sensitive gas counter (1 mm granularity) - Tracking o Ge-detectors - MWPC & IC o Z- identification - tape system - focal plane spectroscopy - , proton, , , -delayed protons and alphas - prompt and delayed coincidences - in-beam spectroscopy tagging with using focal plane measurables
X-deviations versus TOF can be seen in phase space corrected data -> time correction can be made to improve x-resolution
Simulation of electric field in deflector (code Poisson Superfish) • gap 14 cm • rounded edges • splitted anode • maximum voltage between plates is about 0.5 MV
Simulating particle trajectories in deflector field Simple modified Euler equation is used to trace particles in electric field. 147Tm: 222 MeV, 147 u, 37 e Real transfer matrix coefficients can be obtained from these simulations. This more realistic matrix can be used in optical simulations of the new separator. 92Mo: 362 MeV, 92 u, 32 e 100 MeV, 100 u, 26 e 200 MeV, 50 u, 21 e
JIono – ionoptical simulations, Jan Sarén • Features (some are not implemented yet): • both graphical and text interfaces • uses GICO/GIOS transfer matrices • adjustable aperture slits • export/import data • real particle parameters as input data (m, E, q) • Multiple types of plots • Windows and Linux