Advisors:Rurng-Sheng Guo Wen-Chen Chang Graduate: Su-Yin Wang 2009/06/19, NKNU

 Introduction  PHYDES01 Production  NMR Measurement  Signal Distortion (Appendix)  Analysis  Result and Conclusion  Discussion and Future 2

Motivation

Diffractive production within the vector-meson-dominance model through Pomeron exchange One-pion-exchange OZI uud ss ss-knockout uud-knockout A.I.Titov et al. Phys. Rev. C58 (1998)

Cross Section at E  = 2.0 GeV Vector-meson- dominance model One pion exchange ss knockout uud knockout A.I.Titov et al. Phys. Rev. C58 (1998) 2429 Pomeron exchange is more ten times than anothers Only the Pomeron exchange is clear. The experimental data are from H. J. Besch, G. Hartmann, R. Kose, F. Krautschneider, W. Paul, and U. Trinks, Nucl. Phys. B70, 257 ~1974!. 5

LEPS data :LD2 LAB angle  CM angle  6

Cross Section at E  = 2.0 GeV Vector-meson- dominance model One pion exchange ss knockout uud knockout A.I.Titov et al. Phys. Rev. C58 (1998) 2429 Pomeron exchange is more ten times than anothers Only the Pomeron exchange is clear. The experimental data are from H. J. Besch, G. Hartmann, R. Kose, F. Krautschneider, W. Paul, and U. Trinks, Nucl. Phys. B70, 257 ~1974!. 7

Cancel the systematic error P A   p p 8

pp AA (  :+1 p:+1/2)(  :+1 p:-1/2) S=+1 S=+2 S=- 1/2 S=+1 S=-1 S=0 S=+1/2 S=+1 S=0 S=+1 S=-1/2 S=+1 S=0 S=+1 S=+1/2  p p 9

Beam-Target double spin asymmetry at E  = 2.0 GeV Strangeness content is assumed to be 0%(Solid), 0.25%(Dashed), 1%(Dot-dashed). (  0,  1 ) is the relative phase between the strange and non-strange amplitudes. A.I.Titov et al. Phys. Rev. C58 (1998)

 Example: t-channel exchange of Λ(1520) photoproduction  Exchange particle is clear to see, if … ▪ Fix the spin and orientation of initial state particles. ▪ The spin and orientation of final state are measured. 11

HD Overview

Polarized this Symmetry requirement hetero-HD (boson “D” and fermion “H”) no Symmetry requirement polarization is low 18.6 days 6.3 days 13

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Photon beam polarizationCircular polarization Photon beam energyE= GeV Photon beam intensity10 6 γ's/sec SpectrometerStandard LEPS magnetic spectrometer Tagger, SC, AC, SVTX, DC1, DC2, DC3, and TOF wall 15

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 Advantage and disadvantage  HD molecule does not contain heavy nuclei such as Carbon and Nitrogen.  Good for experiments observing reactions with small cross section  The HD target needs thin aluminum wires (at most 20% in weight) to insure the cooling.  Target Size  25 mm in diameter; 50 mm in thickness 18

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TC1SCTC2IBC Magnetic field0.15T2T0.15T1T Temperature4.2K1.2K4.2K300mK Time30 mins3 hours30 mins100 days Could we keep polarization at… Could we succeed in polarization? 20

Polarized HYdrogen-DEuteride target for Strangeness (PHYDES)

H2H2 HD D2D2 Extraction HD D2D2 Extraction HD [H] = 1.26% In PHYDES01 [D] = 2.07% [HD] =97.66% 22

Since TC1 not work now

ProcessSolidify HD P H REF measuring Aging time IBC condition SC condition TC condition P D REF measuring Magnetic field0T1.08T 0.15T7.26T temperature14~22K4.2K14mK0.3K1.2K4.2K Time [HD]=97.66%; 0.68 HD was solidified for PHYDES01. After 53 days aging, the relaxation time in three conditions are measured. 24

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Cancellation circuit for keeping away signals which enter in Lock-in Amp at direct without entering in the coil. 16MHz 15MHz 14MHz 28

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 Polarization signal area  Measure reference signal in thermal equilibrium A 30

polarization at thermal equilibrium state polarization decay function combine two function 31

Appendix

 The smallest width of the NMR shape can be estimated from the uncertainty principle.  Precision of frequency.  The non-uniformity of the local magnetic field in a superconductor  The non-uniformity of the local magnetic field from the induced current of aluminums wires and cool finger. 33

B real ΔBΔB B center ΔB B center Magnetic field uniformity profile Measurement value Fitting by 4 th -order polynomial 34

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 The PHYDES01 use 0.68 mole HD only. The smallest cell size is 34 mm. The biggest size is 80 mm (the length of aluminums)  This result shows the most likely cell position around -14 cm and cell length around 46 mm. 36

 Preparation of Analysis  Unification of the Signal Amplification  Magnetic Field Adjustment  Data Position Shift  Unification of Bin Size  Phase Adjustment  Extracting the Signal Area (Relaxation Time)  Histogram Method  Model Method  Extracting the Signal Area (Polarization)  Histogram Method  Model with Deviation Method  Error Estimation  Relaxation Time Estimation  Polarization Estimation 38

The original data with the sensitivity = (1mVrms/-47dBm) The signal is ten times of original one. We also change the signalshape to positive. 39

B -1 B0B0 B1B1 B3B3 B2B2 B -3 B -2 ~ B 50 B -50 ~ reset 40

After Peak Shift 41

 If bad phase …  If good phase … Quadrature In Phase Quadrature 42

 After remove background, for each pulse, start analysis 43

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 Fitting example 46

D:IBC,18hours,θ=0.4H:IBC,332hours,θ=0.75  H model increase decrease increase decrease  D model 47

 Fitting example 48

Zoom in each signal Average of 73 signals 49

Same as discussed in extracting the signal area of relaxation time 50

Bad fitting by signal deviation 51

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Gauss deviation= E-04 D model at 300mK, 1.08T D model with Gauss deviation Fit the sigma of deviation in small region Use the sigma to fit the background 53

polarization at thermal equilibrium state polarization decay function combine two function 55

left right combine Original New error 56

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Consistent Inconsistent 59

 Histogram method  Model method H, TC, increase, 47 hours

 Histogram method  Model method D, TC, decrease,46hours

 When extract the signal area of polarization, peak up the model method.  When extract the signal area of relaxation time, peak up the histogram method. 62 [M]

 The production polarized of HD target succeeded,  If the initial polarization is assumed to be 100%, the H polarization becomes 98% and D polarization becomes 97%  The relaxation times in the SC and TC condition are found to be long enough compared with the staying time needed for the transportation of the HD target.  The relaxation time in the IBC condition is found to be long enough to produce a new polarized HD target for replacement in continuous experiments. 63

 Study of Aging Time  Lower Polarization  NMR Measurement  Improvement of D Polarization  From Success of Polarized HD Target to Using the Polarized HD Target in LEPS Experiment 65

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 For sweeping magnetic field, one need to break superconductor-state of magnet, and turn the magnet to drive-state. It waste a lot of liquid helium.  If the polarization of D and H are both measured, the magnetic field sweep from 1T to 7T will generate a lot of heat and waste a lot of liquid helium.  The significant change of magnetic field, make the polarization of HD unstable. Cannot be avoided Can be avoided easy by separating the cancellation circuits of H and D, 68

D. Babusci et al., LEGS expt. L18/L19 (1994). The time line from LEGS group

 The Difficulties of FAFP and SFT  The concentration of o-H 2 can not be handled easy now.  The concentration of p-D 2 can not be handled easy now. (p-D 2 should be ~0)  The amounts of heat depend on the amounts of HD and RF power.  The relation between concentration of o-H 2 and the relaxation time of H is not well known enough. 70

 There are still many subjects that we have to work on:  Installation of HD target system in the LEPS experiment hutch.  The transit of HD target from RCNP to SPring-8/LEPS.  Acceptable trigger rate for data taking. 71

Thank you for your kind attention.

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TC1SCTC2IBC Magnetic field0.15T2T0.15T1T Temperature4.2K1.2K4.2K300mK Time30 mins3 hours30 mins100 days H Relaxation time~147 hours~277 hours~147 hours~2546 hours Remained Polarization of Init P H 99.66%98.58%98.24%38.27% Init P H = 41.4 % D Relaxation time~48 hours~303 hours~48 hours~1740 hours Remained Polarization of Init P D 98.96%97.98%96.96%24.41% Init P D = 12.2 %12.07%11.83% 2.95%

Hysteresis from cold finger and aluminum wire 76

HD Polarization41.4%12.2% Temperature estimate by the polarization (Assume B=17T) ~40mK~29mK  Bad linearity of the NMR signal height.  Bad Thermal conductivity of Al wires or Kel-F NMR coil supporter 77

 NMR system – to correctly measure the polarization.  NMR system – to increase Signal/Noise ratio.  Al wires or NMR coil supporter -to decrease the HD temperature.  Distillator - to improve the purity of HD 78

 Practice of transferring the target by using a solid H2 target  A polarized HD target after the aging of 2~3 months will be ready for the experiment.  install the HD target system in the LEPS experiment hutch. (  Support frames for the IBC and TC2 will be constructed.  IBC and TC2 will be transferred from RCNP to SPring-8/LEPS.  Circularly polarized ultra-violet laser beam will be prepared.  Check the polarization of the HD target can be kept when the photon beams of ~1 M γ‘s hit the target.  Check trigger rate for data taking is acceptable. 79

Appendix

 Histogram area  Histogram model D, IBC, decrease,69hours 81

Model method Histogram method H Polarization & IBC data C. Morisaki, Master thesis of Osaka university (2009). 82

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θ=0 θ=0.8 θ=0 84

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0212 increase Big rangeSmall range 88

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Cooling power DRS Thermal sensor HD target 91

 Magnetic field=17T  Temperature=17mK Cooling power DRS Thermal sensor HD target 92

 the Log P Time Empty cell HD 93

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