Henrik B Jeppesen, INTC meeting 22nd of May 2006

Aarhus-CERN-Darmstadt-Göteborg-Madrid-Sevilla Collaboration

Henrik B Jeppesen, INTC meeting 22nd of May 2006

Motivation for new experiment

• Aim: Demonstrate reaction model reliability (extraction of SF) at low beam energy (3 MeV/u) for loosely bound nuclei

• Compare 9Li(p,d)8Li (9Li(d,t)8Li) with 8Li(d,p)9Li

• Conflicting data sets exist!

• At present 8Li(gs)9Li(gs) most exotic system which allows complete test

M.B. Tsang et al. Phys. Rev. Lett. 95 (2005) 222501

J. Lee et al., Nucl-Ex/0511024

Henrik B Jeppesen, INTC meeting 22nd of May 2006

Previous 8Li(d,p)9Li experiments• 4.875 MeV/u• ~103 8Li/sec• 1.66*108 8Li in total• ~50 identified 9Li• SF(gs→gs) = 1.68±0.23

to 1.02±0.16

A.H. Wuosmaa et al., Phys. Rev. Lett. 95 (2005) 082502

B. Gou et al., Nucl. Phys. A761 (2005) 162

• 9.5 MeV/u• ~5*104 8Li/sec• ~1500 p from 9Li(gs)• SF(gs→gs) = 0.90±0.13

Henrik B Jeppesen, INTC meeting 22nd of May 2006

Recent 9Li(d,t)8Li experiment

H.B. Jeppesen et al., Phys. Lett. B635 (2005) 17

H.B. Jeppesen et al., Nucl. Phys. A748 (2005) 374

• 2.36 MeV/u• ~5104 9Li/sec (1.8109 in total)• 400 t from 8Li(gs)• SF(gs→gs) = 1.9±0.3 or 2.3±0.4

Henrik B Jeppesen, INTC meeting 22nd of May 2006

SF from transfer reactions

• Extraction of SF at:– Smaller binding energy– Lower beam energy

M.B. Tsang et al., Phys. Rev. Lett. 95 (2005) 222501

J. Lee et al., Nucl-Ex/0511024

(d,t)

(p,d)

(p,d)

Henrik B Jeppesen, INTC meeting 22nd of May 2006

8Li(gs)9Li(gs) a good test case

Study the following reactions at 3 MeV/u:

9Li+p→d+8Li

9Li+d→t+8Li

8Li+d→p+9Li

Only need to perform the “easy” 8Li+d reaction

May have to introduce more complex reaction models (e.g. CCBA applied for 9Li(d,p)10Li)

H.B. Jeppesen, A.M. Moro et al. submitted to Phys. Lett. (CERN-PH-EP/2006-010)

Also provides improved data to predict rate of astrophysical 8Li(n,)9Li reaction.

Z.H. Li et al. Phys. Rev. C71 (2005) 052801(R)

Henrik B Jeppesen, INTC meeting 22nd of May 2006

Reaction kinematics

• 3 MeV/u 8Li on CD target• protons detectable in full

angular range• Only proton background

from 16O(d,p)17O and from compound.

Proton contamination Other contamination

8Li(d,p)9Li Lab. vs CM angles

Henrik B Jeppesen, INTC meeting 22nd of May 2006

Beam intensities

8Li REX yield:

5.8108 µC (thin Ta) ~11010 /pulse (std. Ta)

Rex efficiency ~ 2-0.5 % 5107 at target

16O REX yield:

1-5107 16O/s

C-stripping at 3 MeV/u reduction factor ~1/17 up to 3106 /s on target

about 5% contamination of 16O

Possible to accelerate 8Li as either 2+ or 3+

Stripping to 3+ needed in any case

Henrik B Jeppesen, INTC meeting 22nd of May 2006

Experimental setup

DSSSD telescope:

3232 strip DSSSD 60 µm

+ 1.5 mm Si-padDSSSD Telescope

DSSSD Telescope

DSSSD Telescope

Target

• Particle identification above 2-4 MeV

• 10-170o lab. coverage

Henrik B Jeppesen, INTC meeting 22nd of May 2006

Beam Request

For the 8Li(d,p)9Li reaction we therefore request:

1 shift for beam tuning

9 shifts for 8Li on CD target

1 shift for 8Li on CH target

2 shifts for 8Li on C target

In total 13 radioactive shifts is requested

Additional 1 shift of stable 16O needed