@ PST05, Nov.14-17, 2005

T. Kageya1,2

on behalf of LEGS Spin Collaboration

1. Brookhaven National Lab., Upton, NY, USA2. Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

*

* Supported by a research grant from the U.S. Department of Energy and the U.S. National Science Foundation

Performances of frozen-spin polarized HD targets for Nucleon spin experiments.

MotivationMotivation

Nucleon Spin Sum Rules

Gerasimov−Drell−Hearn

Nucleon spin strucure at Q2=0

LEGS covers ~65%Measurement down to pion threshold is important

Forward Spin−Polarizability

Test of chiral perturbation theories

LEGS covers ~90%Measurement down to pion threshold is important

γ dE3γE

3/2σ - 1/2σ∞

πm∫2π4

1 =0γ

γ dEγE

3/2σ - 1/2σ∞

πm∫2π4

1 =2κ22mα-

Multipole Amplitudes

Double polarization observablesAsymmetries E and GNeutron channels πon and π−p

Attractive Features Polarized HD Target

1. Pure Solid Targets

* Only unpolarizable nucleons associatedwith target cell which can be measured separately and subtracted in coventional way

2. Long Spin-Relaxation time

~ 1 year in beam

3. H D : Higher D polarization

4. H D

Can Select H D

H D

Polarize H in HD using polarized ortho -H 2

H 2

Ortho -> Para

Para

Polarize H at 12mK, 15 T

Spinexchange

Polarized H in HDH 2

Ortho

Para

HD : L = 0

L =1

L = 0

No spin exchange to HD (Frozen Spin)

H H

H H

HHH

HH

H H H H

DD

DD

12 mK, 15 T Age: ~ 3 months

(Half in 4.5 days)

0

20

40

60

80

100

0 10 20 30 40 50 60 70 80

Eq

uil

ibri

um

Po

lari

za

tio

n [

%]

T [mK]

HD at 15 Tesla

H vectorD vectorD tensor

Expected Polarizations

12 milli−Kelvin and 15 Tesla

HD target Produced, Calibrated,

Polarized and On the beam

Down to 10 - 4 of H2 in HD

PD: 2 K, 2 T

DF: 12 mK, 15 T

IBC: 0.3 K, 1 T

: TC: 2 K, 0.12 T

Polarized and Aged

Distillation

(1) HD ice productionTE calibration

(2) Polarization Measure.

(3) Polarization Measure.

On BeamMonitor PolarizationT1 Measurements

Cross-Coil NMR for Measuring Target Polarization

H D

Typical NMR Scans for the SPHICE Target at TE

Hydrogen Deuterium

����������� �� � ��� �������

� ������ !"#$%&%&'(

) *,+ -/.0)21

-3+ -

*3+ -�.3)41

5 + -�.3)4*

5 + *�.3)4*

6 + -�.3)4*

6 + *�.3)4*

����������� �� � ��� �������

�7����� !"#$%&%&'(

) 5 + */.0)2*

) 5 + -/.0)2*

) *,+ -/.0)21

-3+ -

*3+ -�.3)41

5 + -�.3)4*

5 + *�.3)4*

����������� �� � ��� �������

� ������ !"#$%&%&'(

) */+ -,.8)41

-3+ -

*3+ -�.3)41

5 + -�.3)4*

5 + *�.3)4*

6 + -�.3)4*

6 + *�.3)4*

����������� �� � ��� �������

�7����� !"#$%&%&'(

) 5 + *,.8)4*

) 5 + -,.8)4*

) */+ -,.8)41

-3+ -

*3+ -�.3)41

5 + -�.3)4*

5 + *�.3)4*

UpDown

UpDown

NMR Signal =

9,:<;=; 9?>�; ; >�; :<;�;

9,:<;=; 9?>�; ; >�; :<;�;

9,:<;=; 9?>�; ; >�; :<;�;

9,:<;=; 9?>�; ; >�; :<;�;

Summary of HD target polarizations during recent runs at LEGS

Fall 2004 17 days + 7 % + 53 %, - 26 %

Year Duration P(D) P(H)

Spring 2005 32 days + 31 % + 30 %, -7 %

0 100 200 300 400 500Time +hrs/

�0.2

0

0.2

0.4

0.6

0.8noitaziralo

PTarget #3 Polarization during November 2004 Run

T1#D' 238 day

T1#H' 241 day

T1#D' 292 day

T1#H' 883 day

p in PD

p in QIBC

d in PD

d in QIBC

Summary and Rationalization of Fall and Spring Data v1.nb 1

Spin transition: H HAllowed fast passage RF transition

mD = - 1mD = 0

mD = + 1

ab

c

mH = -1/2

mH = +1/2d

e

f

!

�

"#

���� � ��� � �� �� � � � � � � � ��� �� � ��!

$!

�� �� � � � �

!

�

"#

�� � � � � � �� �� � � � � � � � �� � � � ��!

$%

� � �� � � � �

$,"#

$&��� ��

�Fall'04: P(H) = 53%,P(D) = 7%

Spin transition: H D Saturated Forbidden RF Transition

mD = - 1mD = 0

mD = + 1

ab

c

mH = -1/2

mH = +1/2d

e

f

Nd > Nb, Ne > Nc Nd = Nb, Ne = Nc

0 200 400 600 800Time +hrs/

0

0.2

0.4

0.6

0.8noitaziralo

P

Target #4 Polarization during April 2005 Run

T1#D' 345 day

T1#H' 187 day

T1#H' 243 day

7�Occcccccc2

Occcc2

H in PD

H in QIBC

D in PD

D in QIBC

Summary and Rationalization of Fall and Spring Data v1.nb 1

0

100

200

300

400

500

600

700

800

-200-150 -100 -50 0 50 100 150 200

helicity 1/2! + D

empty cell

full cell

0

100

200

300

400

500

600

700

800

-200-150-100 -50 0 50 100 150 200

helicity 3/2! + D

empty cell

full cell

0

100

200

300

400

500

600

700

800

-200-150-100 -50 0 50 100 150 200

E"#

Missing Energy (MeV)

helicity 1/2! + D

LEGS production run #2, deepUV-1 (Spring'05)

D(!,"#n) P

! = 92% P

D = 31%

E! = 341 MeV $cm

("#n) = 105

o

0

100

200

300

400

500

600

700

800

-200-150-100 -50 0 50 100 150 200

E"#

Missing Energy (MeV)

helicity 3/2! + D

- target cell and Al wirescontain the only unpolarizable nucleons;

- background is sampled in runs with an empty cell

D(g,pi0n)341MeV105 full&empty_FS

-1.0

-0.5

0.0

0.5

1.0

0 30 60 90 120 150 180

Ea

sy

286 ±7 MeV

-1.0

-0.5

0.0

0.5

1.0

0 30 60 90 120 150 180

Ea

sy

!Lab

(deg)

349 ±5 MeV

-1.0

-0.5

0.0

0.5

1.0

0 30 60 90 120 150 180

D(",#$n) LEGS run#2, deepUV-1

D(",#$n) T.S.-H. Lee [Impulse]

n(",#$n) SAID[FA04K]

!Lab

(deg)

396 ±7 MeV

D(",#$n)

PD = 30% (avg)

Spring'05

2nd

Production run

% %

- very preliminary -

LEGS exp schedule FY05-06

Experiment schedule - through 2006 :

! FallÕ04:!H !!D(!" ,# o

) to extract!H(!! ," o

) and!H(!! ," +

)

! FYÕ05:!H !!D(!" ,# o

) to extract!D(!! ," o

)

¥ SeptÕ05-JanÕ06: install Time-Projection-Chamber

¥ FebÕ06 ÐAprÕ06: H2(! ," +

) , D2(! ," ±

) calibrations

¥ MayÕ06 ÐJuneÕ06:!H !!D(!" ,# ±

) - run 1

¥ AugÕ06 ÐSeptÕ06:!H !!D(!" ,# ±

) - run 2

extract:!D(!! ," #

),!D(!! ," +

),!H(!! ," +

)

¥ OctÕ06: expected end of LEGS experiments

Figures of merit table - Schaerf/Sandorfi Ð NovÕ05

Figures of merit for Butanol and HD

target

Low-resolution and Low-Intensity

!-beam (a)

high-resolution Low-Intensity

!-beam

(b)

High Intensity

!-beam

(c)

Nuclear-background-limited

High Intensity

!-beam (d)

Atomic-background-limited

High Intensity

!-beam (e)

Figure of merit

"eff (P eff)2

1.4 "eff (P' eff)2

(P eff)2 (P eff)

2/A (P eff)

2/Z

2

p in C4H9OH

0.017 0.110 0.23 0.0031 0.0069

n in C4D9OD

0.010 0.010 0.18 0.0021 0.0070

p in HD

0.019 0.067 0.45 0.1500 0.4500

n in HD

0.010 0.014 0.46 0.1500 0.4500

(a) count rate is beam-limited; reactions on p, n distinguished; bound vs free not distinguished; Peff = P¥f

(b) count rate is beam-limited; reactions on p, n distinguished; bound vs free distinguished with cut; Peff = P¥[ Pfree / (Pfree + 0.2¥Pbound) ]

(c) beam flux can be increased as needed; count rate is limited by accidentals; Peff = P¥f

(d) beam flux can be increased as needed; count rate is limited by dead time from nuclear events; Peff = P¥f

(e) beam flux can be increased as needed; count rate is limited by dead time from atomic electrons; Peff = P¥f

complete set of exp

Complete set of measurements with longitudinal target polarization: target beam (1a) P1(H) P1(D) CR , CL , L

(1b) Ð P1(H) P1(D) CR , CL , L

(2a) P2(H) P2(D) CR , CL , L

(2b) Ð P2(H) P2(D) CR , CL , L

separates separates

rH and

rD Dvector and Dtensor

observables observables

- example: ! + HD " #o (from LEGS/BNL)

separates

!, G, E

Separate reactions to n from p with TPC

+ n � p + �--

� n + �0

+ p � n + �+

� p + �0

Separate !

Central tracking_OctÕ05

Central tracking with magnetic analysis in a Time-Projection Chamber

¥ isolate neutron reactions:

! + n " #Ð p

separate

D(! , "Ð p) from D(! , "+ n)

measure the #± charge

TPCLarge-bore 2 tesla solenoid

p" -

" +

LEGS spin experiments

1. Compton backward-scattered polarzied γ beam

3. Polarized HD solid target

0.17 < Eγ < 0.42 GeV

< Pγ > ∼ 90 %

2. 4 π detector

(σ1/2

− σ3/2

)/ Εγ ;

Total cross sections

The LEGS-Spin Collaboration

¥ Brookhaven National Laboratory

A. Caracappa, S. Hoblit, O. Kistner, F. Lincoln, L. Miceli, M. Lowry, A.M. SandorÞ *, C. Thorn, X. Wei

¥ Forschungszentrum J�lich GmbH

M. Pap, H. Gl�ckler, H. Seyfarth, H. Str�her

¥ James Madison University

C. S. Whisnant

¥ Norfolk State University

M. Khandakar

¥ Ohio University

C. Bade, K. Hicks *, M. Lucas, J. Mahon, S. Kizigul

¥ Syracuse University

A. Honig

¥ University di Roma - Tor Vergata

A. DÕAngelo *, A. dÕAngelo, D. Moricciani, C. Schaerf, R. Di Salvo, A. Fantini

¥ University of South Carolina

K. Ardashev, C. Gibson, B. M. Preedom *, A. Lehmann

¥ University of Virginia

S. Kucuker, R. Lindgren, B. Norum, K. Wang

¥ Virginia Polytechnic Institute & State University

M. Blecher, T. Kageya

37 people from

10 institutions in

3 countries

LSC list MayÕ05

Post-Docs (NSF)

Grad Students

* LSC Executive com

γγγγ

ee′′′′

Laser-Electron-Gamma-Source (LEGS)

4ωωωω Nd-YLF

ring laser

Ar-Ion laser

λλλλ(nm) 263 300 351 488 515

Eγγγγ

(max)

471

MeV

421

MeV

368

MeV

275

MeV

262

MeV

NSLS Ee = 2.8 GeV

200 250 300 350 400

Inte

nsi

ty (

arb

. u

nit

s)

Eγγγγ (MeV)

263 nm & 351 nm

263 nm only

Eγγγγ400300

γγγγ beam energy determined by e′′′′ tagging

Eγγγγ = Ee - Ee′′′′ , ∆∆∆∆Eγγγγ = 3 MeVE tag

(min) = 150-180 MeV

SASYSASY CurrentCurrent SetupSetup

γ

Separating H and D data

Separating!H and

!D data with spin flip - example, !o production

Run A:!H !!D with parallel spins Run B:

!H !"D with anti-parallel spins

! !" LA= !

"p(!" ,# o

)$% &' +!"D(!" ,# o

)$% &'

! "" RA= !

"p("" ,# o

)$% &' +!"D("" ,# o

)$% &'

! !" LB= !

!p(!" ,# o

)$% &' +!"D(!" ,# o

)$% &'

! "" RB= !

!p("" ,# o

)$% &' +!"D("" ,# o

)$% &'

!" (p) = " 3/2 #" 1/2( )p= " !$ R

B #" !$ RA%& '( + " "$ L

A #" "$ LB%& '( from "p # !op

$

!" (D) = " 3/2 #" 1/2( )D= " !$

L

A #" "$R

B%& '( + " !$L

B #" "$R

A%& '( from "D # !oX

- similarily, runs with different PD separate Vector and Tensor D-observables

- in general, one fits out different observables from runs with different polarizations

!,"#

"#

!,"#

!,"#

$

µ

!

! "#

Before

After

After

DBefore

H

Forbidden Adiabatic Fast Passage

Efficiency of transfer = 67%

!! " #

! "#

$

�

% , & , #

�

(!)

��� � � � �� � �

��� � � ���

�� �� ���� � � ��

� �� � � � ��� � � � �� � � ��

HD target cycle:

target injection into dilution fridge;

~min 45 days at 15 Tesla / 12 mK

loading In-Beam-Cryostat

¥ 0.25!K and 1.00 Tesla

extraction with Transfer-Cryostat

¥ 2.5!K and 0.120 T

5 cm

HD target cycle-OctÕ04