Advisors: Rurng-Sheng GuoWen-Chen Chang

Graduate: Su-Yin Wang2009/06/19, NKNU

Progress of Polarized Hydrogen-Deuteride (HD)

Target for Strangeness Experiments

at SPring-8/LEPS

2

Outline

IntroductionPHYDES01 ProductionNMR MeasurementSignal Distortion (Appendix)AnalysisResult and ConclusionDiscussion and Future

Introduction

Motivation

4 Kinds of Mechanisms of

The γp →φp Reaction

Diffractive production within the vector-meson-dominance model through Pomeron exchange

One-pion-exchange

OZI

uud uud

ss

ss-knockout uud-knockoutA.I.Titov et al. Phys. Rev. C58 (1998) 2429 4

5

Cross sectionCross Section at Eg = 2.0 GeV

Vector-meson-dominance model

One pion exchange

ss knockout

uud knockoutA.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 fromH. J. Besch, G. Hartmann, R. Kose, F. Krautschneider, W.

Paul, and U. Trinks, Nucl. Phys. B70, 257 ~1974!.

6

Scattering angle

LEPS data :LD2

LAB angle q

CM angle q

7

Cross sectionCross Section at Eg = 2.0 GeV

Vector-meson-dominance model

One pion exchange

ss knockout

uud knockoutA.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 fromH. J. Besch, G. Hartmann, R. Kose, F. Krautschneider, W.

Paul, and U. Trinks, Nucl. Phys. B70, 257 ~1974!.

8

Beam target asymmetrymore sensitive to understand the components of cross section

PA

PABTC

bca

cbacba

AP

AP

A

P

222

Cancel the systematic error

P

A

g

g

p

p

9

p A (g:+1 p:+1/2) (g:+1 p:-1/2)

S=+1

S=+1

S=+2

S=-1/2 S=-1/2

S=+1

S=-1

S=0

S=+1/2 S=+1/2

S=+1

S=0

S=+1

S=-1/2 S=-1/2

S=+1

S=0

S=+1

S=+1/2

S=+1/2CANCELCANCEL

p: polarization of proton is parallel with polarization of target A: polarization of proton is anti-parallel with polarization of target

g g pp

AP

APBTC

content ss

10

Theory

}]][][[

]][][[{

][

2/112/11

2/102/10

2/1

ssuud

ssuudB

uudAP

Beam-Target double spin asymmetryat Eg = 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) 2429

11

Unclear Exchange Particle

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.

Introduction

HD Overview

13

Why we choose HD

Polarized this

Symmetry requirement

hetero-HD (boson “D” and fermion “H”)no Symmetry requirement

polarization is low

18.6 days 6.3 days

14

Small concentrations of ortho-H2

B0

15

Experimental ConditionsPhoton beam polarization

Circular polarization

Photon beam energy E=1.5-2.4 GeVPhoton beam intensity 106 γ's/secSpectrometer Standard LEPS magnetic spectrometer

Tagger, SC, AC, SVTX, DC1, DC2, DC3, and TOF wall

16

HD Target at Other Laboratories

At Institut de Physique Nucleaire de Orsay (IPN Orsay) Magnetic field ~ 15 Tesla Temperature ~ 10 mK PH~ 60%, PD~14%

At the Laser Electron Gamma Source (LEGS) at Brookhaven National Laboratory Magnetic field ~ 15 Tesla Temperature ~ 15 mK The initial :PH~ 59%, PD~7% With Saturated Forbideen Transition (SFT): PH~ 32%, PD~33%

17

HD Target Goal

We can use both proton and neutron.

Temperature ~ 10 mK Magnetic field ~ 17 Tesla The target production take 2~3

month. The target relaxation time ~1

year. Use the brute force: PH~ 90%,

PD~30% If we use forbidden adiabatic fast

passage (FAFP) to invert state polarization. PD can reach to 50%.

HD target cell

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

19

Transport of Polarization HD Target

0.5 hour

s 3 hours

0.5 hour

s

20

Main Problems are …

TC1 SC TC2 IBC

Magnetic field 0.15T 2T 0.15T 1T

Temperature 4.2K 1.2K 4.2K 300mK

Time 30 mins 3 hours 30 mins 100 days

Could we keep polarization at…

Could we succeed in polarization?

Polarized HYdrogen-DEuteride target for Strangeness (PHYDES)

PHYDES01 Production

HD Purify

H2

HD

D2

Extraction

HD

D2

Extraction

HD

HD

[H] = 1.26%In PHYDES01 [D] =

2.07%[HD] =97.66%

22

Solid HD Production

Normal

production No TC

production

Since TC1 not work

now

solidify

solidify

23

24

PHYDES01

Process Solidify HD

PHREF

measuring

Aging time

IBC conditio

n

SC conditi

on

TC conditio

n

PDREF

measuring

Magnetic field

0T 1.08T 1.08T 1.08T 1.08T 0.15T 7.26T

temperature 14~22K

4.2K 14mK 0.3K 1.2K 4.2K 4.2KTime

[HD]=97.66%; 0.68 HD was solidified for PHYDES01.

After 53 days aging, the relaxation time in three conditions are measured.

NMR Measurement

26

Principle of NMR Measurement

0HE

hE

hH0

hH 0

27

Single coil method

Cancellation Circuit

Cancellation circuit for keeping away signals which enter in Lock-in

Amp at direct without entering in the coil.

Single coil method uses one coil takes both transmitter and receiver coil.

16MHz15MHz14MHz28

29

Flow Chart

30

Polarization Estimate

Polarization signal area Measure reference signal in thermal equilibrium

A

ref

targetreftarget

targettargetrefref //

AAP

P

APAP

)(")(')( i

0

)(" dP

31)1))(0(()0()(

)1))(0(()0()(

1

1

targetthermal_eqtargettarget

target

targetthermal_eqtargettarget

ref

targetreftarget

Tt

Tt

eAAAtA

areasignalionpolarizatN

eNNNtN

AAP

P

Relaxation Time Measurement

polarization at thermal equilibrium state polarization decay function combine two function

Shape Distortion

Appendix

33

Account of NMR shape width

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.

1 ;

EE

34

Non-uniformity of Magnetic Field

real012

23

34

4center )PPPP(PB Bxxxx

Breal

ΔBBcenter

ΔBBcenter

Magnetic field uniformity profile Measurement value Fitting by 4th-order polynomial

Simulation

35

36

Advanced Simulation 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.

Analysis

38

Analysis outline 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

Preparation of Analysis–

Unification of the Signal Amplification

The original data with the sensitivity = (1mVrms/-47dBm)

The signal is ten times of original one. We also change the signalshape to positive. 39

40

Preparation of Analysis–

Magnetic Field Adjustment

B-1 B0 B1 B3B2B-3 B-2 ~ B50B-50 ~

101

50

500

i

iBBreset

41

Preparation of Analysis–

Data Position Shift

After Peak Shift

42

If bad phase … If good phase …

Preparation of Analysis–

Phase Adjustment

Quadrature

In Phase In Phase

Quadrature

PhaseIn

Quadraturecossinsincos

'PhaseIn 'Quadrature

qqqq

43

Preparation of Analysis–

Remove the Background

Fit each signal only background part

After remove background, for each pulse, start analysis

44

Extracting the Signal Area (Relaxation Time) –

Histogram Method Fit only

background part fitting

Fill histogram only signal part (green)

45

Extracting the Signal Area (Relaxation Time) –

Histogram Method

46

Fitting example

Extracting the Signal Area (Relaxation Time) –

Histogram Method

47

D:IBC,18hours,θ=0.4H:IBC,332hours,θ=0.75

Extracting the Signal Area (Relaxation Time) –

Model Method H model

increase

decrease

increase

decrease

D model

48

Fitting example

Extracting the Signal Area (Relaxation Time) –

Model Method

Extracting the Signal Area (Polarization)–

Necessary to Take AverageZoom in each signal

Average of 73 signals

Average of “Error of each signal” = 2.05E-3

Error of average signal = 2.72E-4Signal height ~ 1 .5E-3

49

Extracting the Signal Area (Polarization) –

Histogram Method

Same as discussed in extracting

the signal area of relaxation time

50

Extracting the Signal Area (Polarization) –

Model Method

Bad fitting by signal deviation

51

52

Extracting the Signal Area (Polarization) –

Consider Signals Deviation

53

Extracting the Signal Area (Polarization) –

Model Method with DeviationGauss deviation=2.6094655E-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

Extracting the Signal Area (Polarization) –

Flow Chart

54

55

Polarization and Relaxation Time

1

1

)0()(

)0()(

targetthermal_eqtarget

target

targetthermal_eqtarget

ref

targetreftarget

Tt

Tt

eAAtA

areasignalonpolarizatiN

eNNtN

AAP

P

polarization at thermal equilibrium state polarization decay function combine two function

56

Fill histogram

Fill histogram

left

right

combine

Original

New error

Estimation of Statistical Error

sizebin bin ofnumber 000863.0Area of 0.000863 valueRMS Bin Each of

stat

stat

EE

57

Estimation of Systematic Error

2decreaseincrease

aveAAA

22 )()( avedecreaseaveincreasesys AAAAE

sysstatfinal EEE 22

Result and

Conclusion

59

Result

ConsistentInconsistent

Histogram method

Two method comparison–

big signal Model method

H, TC, increase , 47 hours

60

Histogram method

Relaxation time estimation –

Comparison-small signal Model method

D, TC, decrease ,46hours

61

62

Result 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.

[M]

[M]

63

Conclusion 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.

Discussion and

Future

65

Outline of Discussion and Future

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

Study of Aging Time-Data comparision (consider [O-H2])

66

67

Lower Polarization

The polarization degree expected by the aging process is about PH~ 85% and PD~25%.

The polarization degree was obtained as about PH~ 41% and PD~13%.

Bad Linearity of the NMR Signal Height Improvement of Thermal Conduction

Make a new target cell with high purity aluminum wires.

Develop the single crystal HD target.

68

NMR Measurement-Frequency Sweeping or Magnetic Field Sweeping

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,

Improvement of D Polarization Forbidden Adiabatic Fast Passage (FAFP) and Saturated Forbidden Transition

(SFT)

D. Babusci et al., LEGS expt. L18/L19 (1994).

The time linefrom LEGS group

69

70

Improvement of D Polarization

The Difficulties of FAFP and SFT The concentration of o-H2 can not be handled easy

now. The concentration of p-D2 can not be handled easy

now. (p-D2 should be ~0)

The amounts of heat depend on the amounts of HD and RF power.

The relation between concentration of o-H2 and the relaxation time of H is not well known enough.

71

From Success of Polarized HD Target to Using the Polarized HD Target in LEPS Experiment

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.

End

Thank you for your kind attention.

73

74

Remained Polarization TC1 SC TC2 IBC

Magnetic field 0.15T 2T 0.15T 1TTemperature 4.2K 1.2K 4.2K 300mK

Time 30 mins 3 hours 30 mins 100 daysH Relaxation time ~147 hours ~277 hours ~147 hours ~2546 hours

Remained Polarization of Init PH 99.66% 98.58% 98.24% 38.27%Init PH = 41.4 % 41.46 40.81 40.67 14.62

D Relaxation time ~48 hours ~303 hours ~48 hours ~1740 hoursRemained Polarization of Init PD 98.96% 97.98% 96.96% 24.41%

Init PD = 12.2 % 12.07% 11.83% 11.83% 2.95%

75

76

HysteresisHysteresis from cold finger and aluminum wire

77

Target temperature ?H D

Polarization 41.4% 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

78

Next improvement

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

79

Next progress 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.

Reference signal peak up

Appendix

81

Histogram area

Relaxation time estimation –

Comparison-big signal Histogram model

D, IBC, decrease ,69hours

82

Resonance frequency 48.395 MHzH D

gyromagnetic ratio 42.575 6.536Resonance magnetic field 1.1366 7.4044polarization 41.4 ± 3.1% 12.2 ± 1.7%IBC (300mK, 1.0758T)After 53 days aging.

Relaxation time 2546 ± 380 hours (106.1±15.8 days)

1907 ± 273.3 hours(79.5± 11.4 days)

χ2/ndf 1.529/6 0.3354/2SC (1.2K, 1.0758T)After 67 days aging.

Relaxation time 237.5± 12.8 hours (9.9± 0.5 days)

290 ± 44.2 hours(12.1± 1.8 days)

χ2/ndf 1.141/2 0.003523/1TC (4.2K, )After 75 days aging.

Relaxation time 141.4 ± 2.5 hours (5.9± 0.1 days)

44.0± 4.6 hours(1.8± 0.2 days)

χ2/ndf 0.01367/1 0.6168/2

Model method

Resonance frequency 48.395H D

gyromagnetic ratio 42.575 6.536Resonance magnetic field 1.1366 7.4044polarization 41.4 ± 3.1% 13.8 ± 2.2%IBC (300mK, 1.0758T)After 53 days aging.

Relaxation time 2546 ± 380 hours (± days)

1740± 167.6 hours(± days)

χ2/ndf 1.529/6 2.794/2SC (1.2K, 1.0758T)After 67 days aging.

Relaxation time 281.2± 25.6hours (11.7±1.1 days)

302.5 ± 28.6 hours(12.6±1.2 days)

χ2/ndf 1.141/2 0.01654/1TC (4.2K, )After 75 days aging.

Relaxation time 147.3± 3.842 hours (6.1±0.2 days)

47.8± 5.6 hours(2.0± 0.2days)

χ2/ndf 0.7588/1 1.059/2

Histogram method

H Polarization & IBC dataC. Morisaki, Master thesis of Osaka university (2009).

83

Data comparision

84

Phase adjustment

PhaseIn

Quadraturecossinsincos

'PhaseIn 'Quadrature

qqqq

θ=0

θ=0.8

θ=0

85

Ref signal peak up

86

Ref signal peak up

87

Ref signal peak up

88

Ref signal peak up0212 increase

Big range Small range

89

Ref signal peak up

90

Ref signal peak up

91

Heat exchange delay

Cooling pow

er

DRSThermal sensor

HD target

92

Brute force Magnetic field=17T Temperature=17mK

Cooling pow

er

DRSThermal sensor

HD target

93

Get empty cell

the

Log P

Time

Empty cellHD

94

Ref signal peak up

95

Ref signal peak up

96

Ref signal peak up