ELASTIC SCATTERING OF d, He3 AND α ON Li6

(1)

HAL Id: jpa-00214846

https://hal.archives-ouvertes.fr/jpa-00214846

Submitted on 1 Jan 1971

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

ELASTIC SCATTERING OF d, He3 AND α ON Li6

V. Chuev, V. Davidov, B. Novatskii, A. Ogloblin, S. Sakuta, D. Stepanov

To cite this version:

V. Chuev, V. Davidov, B. Novatskii, A. Ogloblin, S. Sakuta, et al.. ELASTIC SCATTERING OF d, He3 AND α ON Li6. Journal de Physique Colloques, 1971, 32 (C6), pp.C6-163-C6-163.

�10.1051/jphyscol:1971628�. �jpa-00214846�

(2)

JOURNAL DE PI-IYSIQUE

Colloque C6, supplkment au no 1 1-12, Tome 32, Novemhre-DPcembre 1971, page C6-163

ELASTIC SCATTERING OF d, He3 AND a O N Li6

V. I. CHUEV, V. V. DAVIDOV, B. G. NOVATSKII, A. A. OGLOBLIN, S. B. SAKUTA and D. N. STEPANOV

Kurchatov Institute of Atomic Encrgy, Moscou, USSR

RQumi.

-

Les sections eficaces de diffusion de d, 'He, et

a

sur 6Li ont Cte mcsurks

B

environ 20 MeV dans le centre de masse. Les diffusions (a +- 6Li) et (d

-1-

6Li) remontent fortcment i I'arrike, cc qui n'est pas lc cas pour la diffusion (3He +- ^6Li).

Abstract.

-

The cross sections of the scattering of d, He3 and

a

on Li6 are measured at the c. m.

energy of about 20 MeV. Thc

^{( a $-}

Li6) and (d

-1-

Li6) scatterings show a considerable backward peak contrary to the He'

-f

Lisscattering.

In the elastic scattering of heavy ions on light nuclei the transfer of several nucleons resulting in the increase of the cross section a t large angles [ l ] is observed.

The cross section of the backward scattering is parti- cularly large when the transfer of a cluster, such as an a-particle in the CIZ + O t 6 interaction, is possible. Li6 ions show a well defined d +

^x

cluster structure, therefore in the scattering of x-particles o n Li6 the transfer of the deuteron accompanied by a strong rise in the cross section in the backward direction may occur. It is predicted [2] that the ground state wave function of the Li6 nucleus has an appreciable He" t component (about half a s large as the

x

+ d component). In this case a n increase of the cross section of the elastic scattering of He3 on Li6 a t large angles must be expected, too.

In the present paper the cross sections of the scat- tering of a-particles, He3 and deuterons on Li6 (Fig. I ) a t the c. m. energies of 21.9 MeV, 22.7 MeV and 14.7 MeV, respectively, were measured. The cross section of the x + ~i~ scattering exhibits diffrac- tion patterns in the whole range of angles and has a strong peak in the backward direction. The backward peak cross section is about 100 times as large a s the Rutherford cross section. This result is in agreement with the suggestion that in the a + Li6 scattering the deuteron exchange takes place. In the d

f

~i~

scattering the cross section is also found to increase with the angle, which can be accounted for the a-particle exchange. The cross section value of the backward peak is somewhat lower than in the former case. This can be possibly due to the large mass of the cluster transferred.

The He3 + Li6 scattering exhibiting diffraction structure at small angles almost monotonously reduces to 1800. No backward peaking is seen. By its absolute value the cross section of the He3 + Li6

I

a

60 420

FIG. 1. -

Differential cross sections of

^{the a}

+

^Li6,^d

+

^Li6

and He3 i- Li6 elastic scatterings.

scattering is appreciably lower in the backward hemi- sphere in comparison with the d + Li6 and a + Li6 scatterings. This implies that the mechanism of the triton cluster exchange does not rnanifest itself in the He3 ^i- Li6 scattering.

Thus, some experiments revealed the cluster struc- ture of Li6

=

He3 + t [3] and others showed the lack of it (the present work and Ref. 4). In this regard it strongly differs from the Li6

=

a + d configuration to which experiments of both kinds are sensitive.

References

[ I ] Voos (U. C . ) ,

VON

OERTZEN

^(W.),

BOCK

(R.), Nuc~. [3]

YOUNG (A. M.), BLATT (S.

L.),

SEYLER (R. G.), Phys.

Phys., 1969,

A 135,

207. Rev. Letters, 1970,

25,

1764.

[4] D ~ v l n o v (V. V.), NOVATSKII (B. G.), OGLORLIN

(A.

A

.),

[2] KURDYUMOV

(I.

V.), NEUDATCHIN

(V. G.),

SMIR- SAKUTA (S. B.), STEPANOV (D. N.), TIMOFEEV

NOV

(Yu.

F.),

Phys. Letters, 1970,

31B,

426. (V. A.), C ~ u e v (V. I.),

J.

Physique, 1972,

32.

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1971628

ELASTIC SCATTERING OF d, He3 AND α ON Li6

HAL Id: jpa-00214846

https://hal.archives-ouvertes.fr/jpa-00214846

Submitted on 1 Jan 1971

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

ELASTIC SCATTERING OF d, He3 AND α ON Li6

V. Chuev, V. Davidov, B. Novatskii, A. Ogloblin, S. Sakuta, D. Stepanov

To cite this version:

V. Chuev, V. Davidov, B. Novatskii, A. Ogloblin, S. Sakuta, et al.. ELASTIC SCATTERING OF d, He3 AND α ON Li6. Journal de Physique Colloques, 1971, 32 (C6), pp.C6-163-C6-163.

�10.1051/jphyscol:1971628�. �jpa-00214846�

Colloque C6, supplkment au no 1 1-12, Tome 32, Novemhre-DPcembre 1971, page C6-163

ELASTIC SCATTERING OF d, He3 AND a O N Li6

V. I. CHUEV, V. V. DAVIDOV, B. G. NOVATSKII, A. A. OGLOBLIN, S. B. SAKUTA and D. N. STEPANOV

Kurchatov Institute of Atomic Encrgy, Moscou, USSR

RQumi.

Les sections eficaces de diffusion de d, 'He, et

sur 6Li ont Cte mcsurks

environ 20 MeV dans le centre de masse. Les diffusions (a +- 6Li) et (d

6Li) remontent fortcment i I'arrike, cc qui n'est pas lc cas pour la diffusion (3He +- 6Li).

Abstract.

The cross sections of the scattering of d, He3 and

on Li6 are measured at the c. m.

energy of about 20 MeV. Thc

Li6) and (d

Li6) scatterings show a considerable backward peak contrary to the He'

Lisscattering.

In the elastic scattering of heavy ions on light nuclei the transfer of several nucleons resulting in the increase of the cross section a t large angles [ l ] is observed.

The cross section of the backward scattering is parti- cularly large when the transfer of a cluster, such as an a-particle in the CIZ + O t 6 interaction, is possible. Li6 ions show a well defined d +

+ d component). In this case a n increase of the cross section of the elastic scattering of He3 on Li6 a t large angles must be expected, too.

~i~

scattering the cross section is also found to increase with the angle, which can be accounted for the a-particle exchange. The cross section value of the backward peak is somewhat lower than in the former case. This can be possibly due to the large mass of the cluster transferred.

The He3 + Li6 scattering exhibiting diffraction structure at small angles almost monotonously reduces to 1800. No backward peaking is seen. By its absolute value the cross section of the He3 + Li6

I

a

Differential cross sections of

+

+

and He3 i- Li6 elastic scatterings.

scattering is appreciably lower in the backward hemi- sphere in comparison with the d + Li6 and a + Li6 scatterings. This implies that the mechanism of the triton cluster exchange does not rnanifest itself in the He3 i- Li6 scattering.

Thus, some experiments revealed the cluster struc- ture of Li6

He3 + t [3] and others showed the lack of it (the present work and Ref. 4). In this regard it strongly differs from the Li6

a + d configuration to which experiments of both kinds are sensitive.

References

[ I ] Voos (U. C . ) ,

OERTZEN

BOCK

YOUNG (A. M.), BLATT (S.

SEYLER (R. G.), Phys.

Phys., 1969,

207. Rev. Letters, 1970,

1764.

[4] D ~ v l n o v (V. V.), NOVATSKII (B. G.), OGLORLIN

A

[2] KURDYUMOV

V.), NEUDATCHIN

SMIR- SAKUTA (S. B.), STEPANOV (D. N.), TIMOFEEV

(Yu.

Phys. Letters, 1970,

426. (V. A.), C ~ u e v (V. I.),

Physique, 1972,

6Li) remontent fortcment i I'arrike, cc qui n'est pas lc cas pour la diffusion (3He +- ^6Li).

scattering is appreciably lower in the backward hemi- sphere in comparison with the d + Li6 and a + Li6 scatterings. This implies that the mechanism of the triton cluster exchange does not rnanifest itself in the He3 ^i- Li6 scattering.