Fukada, Mamoru

Fukunaga, Kiyoji

Kakigi, Shigeru

Kato, Seigo

Ohsawa, Takao

Okihana, Akira

Sekioka, Tsuguhisa

Shimoura, Susumu

Takimoto, Kiyohiko

Tanaka, Seiji

Yokota, Hitoshi

Kyoto University Research Information Repository

Title³He Breakup Reactions by DeuteronsAuthor(s)Okihana, Akira; Fukunaga, Kiyoji; Kakigi, Shigeru; Ohsawa,Takao; Sekioka, Tsuguhisa; Kato, Seigo; Yokota, Hitoshi;Tanaka, Seiji; Takimoto, Kiyohiko; Shimoura, Susumu;Fukada, MamoruCitationBulletin of the Institute for Chemical Research, KyotoUniversity (1987), 65(1): 27-34Issue Date1987-03-23URL http://hdl.handle.net/2433/77179RightType Departmental Bulletin PaperTextversionpublisherKyoto UniversityBull. Inst. Chem. Res., Kyoto Univ., Vol. 65, No. 1, 1987  3He Breakup Reactions by Deuterons      Akira OKIHANA, Kiyoji FUKUNAGA*, Shigeru KAKIGI*, Takao OHSAWA*, Tsuguhisa SEKIOKA**, Seigo KATO***, Hitoshi YOKOTAt, Se TANAKAtt,      Kiyohiko TAKIMOTOttt, Susumu SHIMOURAttt and Mamoru FUKADAtttt                              Received January 31, 1987     Differential cross sections for the 2H(3He,dd)1H reaction at EsHe=120 MeV and 3He(d, dd)1H at Ed=60 MeV have been measured. The Plane Wave Impulse Approximation (PWIA) calculations were done and compared with the experimental data. The shapes of the energy spectra and the cor-relation functions were qualitatively reproduced by the PWIA calculation. However the PWIA calculation overestimated the absolute cross section comparing with the experimental data. The ratio of the experimental data to the calculations becomes small rapidly with decreasing angle.    KEY WORD: Helium-3/ Breakup Reaction/ Angular Correlation/ 1. INTRODUCTION    In recent years, theoretical treatments for the few body system consisting of more than four nucleons have been developed extensively.') So soon, the mechanism of the breakup reaction of the system will be explained by microscopic theories, but at present stage it is not established yet. Thus the tightly bound particle such as 4He is approximated as one particle at a few tens MeV region, and three nucleon-like calculations can be applied to the three body breakup reaction such as d+4He—› p+n+4He2). It is well known that the quasifree scattering (QFS) process is an important mechanism in the breakup reaction of such particle system. However its not confirmed for the three body system consisting of the loosely bound particle such as deuteron and 'He. To study the 'He breakup reactions by deuterons is interesting at this point. Slaus et al. studied the 2H(3He, dd)'H reaction and the 3He(d, dd)'H reaction at Ec.m•=13.5 MeV and 21 McV3) and concluded the QFS description (PWIA) did not explain the reaction mechanism. In our previous study for the 'He (d, dd)1H reaction at Ec.m =36 MeV4) whose measurements were kinematically restricted in the region including the zero energy point of the unobserved proton, the d+3He system could be treated as the d+d+p system. And the QFS process was observed as an important mechanism and also observed that the multiple scattering 7 : Kyoto University of Education, Kyoto.   * fft,77t_7_1, ota, :kR*A : Facility of Nuclear Science Research, Institute for Chemical Re-    search, Kyoto University, Kyoto.  ** RINA : Himeji Institute of Technology, Himeji. *** jjpffigrT, : Yamagata University, Yamagata.   t 4AFEI _ : Tokyo Institute of Technology, Tokyo. tt W : Michigan State University, East Lansing, Michigan, USA. ttt **me—,-FA : Department of Physics, Kyoto University, Kyoto. lilt F$ : Kyoto College of Permacy, Kyoto. ( 27 )             A. OKIHANA, K. FUKUNAGA,S.  KAKIGI, T. OHSAWA, T. SEKIOKA,S..KATO,                H. YOKOTA, S. TANAKA,K. TAKIMOTO, S. SHIMOURA and M.FUKADA calculation with the double scattering term improved the insufficiency of the PWIA calculation. Thus the aim of present study is to confirm these descriptions via d-F3He system by measuring in other kinematical conditions. Measurements were done for both the 3He induced reaction and the deuteron induced reaction. Also the correlation functions of the breakup cross sections were investigated.                    2. EXPERIMENTAL PROCEDURE(1) The 2H(3He, dd)1H reaction    The 3He beam of 120 MeV from the AVF cyclotron at Research Center for Nuclear Physics (RCNP) of Osaka University bombarded a deuterium gas target. Deuterium gas was filled in a 16 cm diameter chamber with 10 ,um thick Havar windows and pressured at absolutely 3 atm. For defining the target volume, a double-slit system was used. In this system, the laboratory angular spread was less than 0.4°. Counter telescopes denoted by A, B, C and D were consisted of a 200 ,am or 300 ,am thick Si dE counter and a 25.4 mm thick NaI (T 1) E or a 3 mm thick Si E counter. Counters A and B were set on one side of the beam and counters C and D were set on the other side of the beam. Two deuterons were detected coincidently by counters A and D or B and C at laboratory angles (8k, 02)=(15.0°, 66.7°), (17.5° ,65.2°), (20.0°, 63.4°), (22.5°, 61.4°), (25.0°, 59.3°), (30.0°, 54.8°), (35.0°, 50.1°), (40.0°, 45.2°), (42.5°, 42.8°) and (47.5°, 37.7°), with 01=0° and 02=180°, respec-                                 E'<100                                                       °D 4\c,0° Si iE/010117,10 C           Si E A10°                   0\4•w-! '-~/®                 ~'~-~NaI(Tt) d-beam/.11lla1iSlits to aFaraday cup            3He gas NaI(TL) Siz E 44/ A Q•          Fig. 1. The experimental set up for the 3He(d, dd)1H reaction at Ed=60 MeV. ( 28 )                          'He Breakup Reactions by Deuterons tively. Overall energy resolution was about  1 MeV.  4E, E and timing signals were sent to the coincidence circuits and accumulated through the raw data processor and PDP 11/40 system on magnetic tapes. Data reductions were made by the FACOM M-180 II AD computer of the Institute for Chemical Research of Kyoto University and the MELCOM-700 computer of Kyoto University of Education. (2) The 3He(d, dd)1H reaction    The deuteron beam of 60 MeV from the AVF cyclotron at RCNP bombarded a 3He gas target. The experimental setup is shown in fig. 1. The gas cell was same as the one in exp. (1) and 3He gas was filled at the absolute pressure of 3 atm. In the double-slit system, the laboratory angular spread was about 0.5°. Five counter telescopes denoted by A, B, C, D and E which were similar to the ones in exp. (1) were used. The thickness of the counters were 100 ,am or 200 am for a Si dE counter, 25.4 mm for a NaI (T 1) E and 5 mm for a Si E counter, respectively. The counter A was set on one side of the beam and counters B, C, D and E were set on the other side of the beam. Two deuterons were detected coincidently by counters A and B, A and C, A and D or A and E at angular region of 25° < 0, 48.5 ° and 22.5° < 02 58.5° with 01=0° and 952=180°. Overall energy resolution was about 1 MeV.    The data acquisition and reduction system was same in exp. (1) .                     3. RESULTS AND DISCUSSIONS (1) The 21-1(31-1e, dd)'H reaction     Coincidence energy spectra of deuterons for the 2H(3He, dd)1H reaction were obtained. A typical map at angles (0, = 35.0°, 02 = 50.1°) was shown in fig. 2. Concentration of yields was seen in the figure. Measured angular set kinematically corresponds to the projectile breakup QFS region including the zero energy point of the unobserved proton in the beam system. As the projectile mass is larger than the target mass, a three body breakup locus is kinematically restricted into a very small region on a correlation map. In this kinematical condition, small angular deviations change the locus drastically. Because the finite angular resolution in the experiment, coincidence yields spread into the localized area. At other angular sets similar correlation maps were obtained. Experimental cross sections were summed over the area and listed in table 1.    The PWIA calculations were done. The formula for the projectile breakup reaction are described as follows, do-  ki (E°m)2E3Epklkz 1 1 2  (do yid      dS2,dS22dE1 kfpE,ET(k,E,+E2 (k,—p cos 0,-Fk, cos 012)) \c1SQ/°m' where the momenta of the projectile, the scattered deuteron 1 and 2 in the laboratory system are p, k1 and k2. E1 shows a total energy of a particle i. E1 means the energy of the transferred particle from the projectile. k; and k f are the relative me-menta of the projectile and the transferred particle in the two body initial state, and ( 29 )              A. OKIHANA, K. FUKUNAGA,S. KAKIGI, T. OHSAWA, T.  SEKIOKA, S. KATO,                 H. YOKOTA, S. TANAKA,K. TAKIMOTO, S. SHIMOURA and M. FUKADAI 1 1 I I----------------------------------------------------------------------------------------------------------------------1 (35.0°,50.1°) -                                  COUNTS • 5- 9     -50•10-19 -                                       920-29 030-39           >-40--                a, 2                                .•• •• •• ••                                   • 000o  -20- I I I I1 t------------------------         20 Edl(MeV)5080           Fig. 2. The correlationmapfor the 2H(3He, dd)IHreaction at E3,g=120                  MeV at angles (35.0°, 50.1°).                Table I. Summed crosssections in the 2H(3He, dd)1H reaction (0,, 02) da (exp.) (mb/sr2) do (PWIA) (mb/sr2) N     (15.0°, 66.7°) 44.82+1.8224400.018     (17.5°, 65.2°) 41.30±1.8715480.027      (20.0°, 63.4°) 58.87±2.28934.50.063      (22.5°, 61.4°) 49.65±1.90626.70.079      (25.0°, 59.3°) 47.89±1.63428.00.11      (25.0°, 59.30)* 45.09±1.64402.60.11      (30.0°, 54.8°) 52.81±1.64443.40.12      (30.0°, 54.80)* 50.57±1.77408.60.12      (35.0°, 50.10)* 80.32±2.19432.70.19      (40.0°, 45.20)* 101.93±2.53573.40.18      (42.5°, 42.80)* 108.64±2.57470.70.23      (47.5°, 37.70)* 97.56±2.43463.50.21   No mark shows the experiment in the B-C system and * shows the one in the A-D system. deuteron 1 and 2 in the final state, respectively. The used dd elastic scattering cross section data are shown in other paper4).1 0 1 2 is the momentum distribution of deuteron in 'He'). For each experimental angular set, the calculations were done for all of the possible kinematical loci considering the angular acceptance of each counter and summed. Moreover the reduced cross sections were summed over the locus. The ratios N of the summed cross section by the experiment to the one by the ( 30 ) 3He Breakup Reactions by Deuterons _ 1 ---------------------------------------------------------------            N-VALUE T13 -            ®(MeV)-                              ••       •-0.1•107 .                       • • 5-                    • •           30 60 90 120cm. (deg)        Fig. 3. The angular dependence of the ratio N of the experimental cross ection to               the calculated cross section by PWIA. The solid curve showsthe relative               energy between one of the scattered deuterons andtheunobserved proton ( 713) calculation were also listed in table 1. The ratios N were plotted versus the deuteron angle in the two deuterons center of mass system in fig. 3. The solid curve in the figure shows the relative energy between one of the scattered deuterons and the unobserved proton (T13). As seen in the figure, the ratio N becomes small rapidly when the angle decreases and correspondingly T13 becomes small. Similar results were seen in other few body breakup reactions such as 2H(p, p')5), 3He(p, 4He (p, p')5), 4H(d, dp)n6), 3He(d, dd)1H4) and 2H(4He, 4Hep)n7)• If 'the PWIA was a good description, N should be constantly 1. Thus the existence of such angular dependence of N suggests that the unobserved proton cannot behave as a spectator in this reaction mechanism even in the kinematical QFS region. According to the multiple scattering calculation') for the 3He(d, dd)1H reaction, the dp interaction succeeds to the first dd interaction and this effect reduces the cross section. When the relative energy T13 becomes small, the dp interaction becomes effective. Thus the ratio of the experimental cross section to the PWIA one which includes only the first interaction decreases in the small angular region where T13 becomes small. This feature explains the present experimental results well. The maximum value of the ratio N is about 0.25. This value is very small. In the present experiment, the total energy in the center of mass system (Ec.m.) corresponds to 48 MeV. In the previous data for the 3He (d, dd)1H and 2H(3He, dd)1H reactions corresponding to Ec.m.=13.4 MeV, 21 MeV and 36 MeV, the maximum values of the ratio N are about 0.1, 0.14 and 0.3, respectively. So the energy dependence of N is not so clear compared with the three nucleon system. (2) The 3He(d, dd)1H reaction    Coincidence energy spectra of deuterons for the 3He(d, dd)1H reaction were obtained. Yields were seen along the three body kinematical line. Data are pro-                            ( 31 )               A. OKIHANA, K. FUKUNAGA,S. KAKIGI, T. OHSAWA,  T.SEKIOKA, S. KATO,                   H. YOKOTA, S. TANAKA,K. TAKIMOTO, S. SHIMOURA and M. FUKADAdct  mb                       dS21dQ2dEi" sr2MeV'T3L(MeV) N=0.20 (35°28.5°) N=0.30 (35°48.5°)   36 5          2 1 r ~1 ¢ 4  7r                                          `1 '1 2 • 0./" 0 N=0.25 ( 5:38.5°) N=0.20(3 :58.5')   36      2 i I4 II I   12 1 r                          ~ r •                                                        yI 0 0                         1i 20 30 40 0 1 20 30 40 Ed1 (MeV )                  Fig. 4. Projected deuteron energy spectra for the 3He (d, dd)1H                         reaction at Ed=60 MeV. Measured angular sets are                         written in each figure, with C=0° and 02=l80°, res-                        pectively. Dashed curves show the laboratory energyof the unobserved proton (T,L). Solid curves show the                        PWIA calculations multiplied by N written in the figure.  jected on the one of the deuteron energy axis. Examples of the projected spectra are   shown in fig. 4. Experimental angular sets are written in the figure. The dashed   curves in the figure show the laboratory energy of the unobserved proton T3L. Broad   bumps whose peak positions correspond to the minima of T3L are seen in all figures.   They correspond to the QFS bumps. The PWIA calculations were done and com-  pared with the data. Solid curves in the figure show the results of the PWIA calcu-  lations which are multiplied by N. The shapes of the bumps are qualitatively re-  produced by this calculation. However for the width of the bump, the one by the   calculation is wider than the experimental one. The PWIA calculation overestimated   the absolute cross section comparing with the experimental data. The ratios N of the   experimental data to the calculations are written in the figure. Peak cross sections   of the bumps are plotted versus the deuteron angle 02 for each fixed angle 01 in the   fig. 5. We call these as correlation functions. As seen in the figure, correlation   functions have bumps. The dashed curve corresponds to the energy T3L. Grossly   the maximum position of the bump is near the minimum energy position of T3L.   However, in detail we see, at the region of 01<30°, bump peaks deviate toward the   smaller angle of 02. At 01 is near 45°, bump peaks become consistent with the   minimum point of 02. Solid curves in the figure show the results of the PWIA calcu-  lations multiplied by 0.25. The PWIA calculation reproduces the bump shape   qualitatively except at 0,<30°. Then it is suggested that near the kinematical   QFS region, the PWIA calculation reproduces the experimental results and at the (32)                                   'He Breakup Reactions by Deuterons                                ..T3L           ~_25e--------------------------------------------------------t—~38-(MV)  2- Y—V\-4    l1 1 - . \T~                   - °               .-2 1)--        2 0. I ,..-I--------------------------------°.0                             CV        28°                                                   40-6                 l             -a 2-°^T~-      . —-4 G.—!-2 -p —0------------------------------II•_                , 30° ,                                             I'—' I 0       2-~'\_45°_ V\                                                                         -4           . .~.—-2 0I~'I--             3- \ /I) j 35° _ 48,5_     2_ _V-4   ,-------------------------------------------------0 0 30 60 0 30 60 02 (deg )                 Fig. 5. Correlation functions of the differential cross sections for the Vie (d, dd)1H                         reaction. Experimental angles 81 are written in each figure and 0, are                         presented by abscissas. Dashed curves show the laboratory energiesof the                         unobserved protons (T,L). Solid curves show the PWIA calculations                      multiplied by 0.25.       region deviated from the kinematical QFS region, It fails to do.                                 4. SUMMARY           The QFS process is an important mechanism in the 3He breakup reactions by       deuterons. The QFS bumps whose peak positions correspond to the minimum        energy points of the unobserved protons were seen in all deuteron energy spectra.       The PWIA calculation reproduces the shapes of the energy spectra and the correlation        functions near the kinematical QFS region qualitatively. However as for the absolute        cross section and the angular dependence, experimental results cannot be reproduced        by such a simple mechanism even in the kinematical QFS region. The relation ( 33 )            A. OKIHANA, K. FUKUNAGA,S. KAKIGI, T.  OHSAWA, T. SEKIOKA, S. KATO,                H. YOKOTA, S. TANAKA,K. TAKIMOTO, S. SHIMOURA and M. FUKADA between the angular dependence of the ratio N and the relative energy T13 suggests the interaction of the unobserved proton with one of the scattered deuterons becomes effective and the proton cannot behave as a spectator in this reaction mechanism. Multiple scattering correction including the double scattering term will improve the absolute cross section and the angular dependence. According to this, three body model seems to be successful despite the loosely bound constituents in the kinematical QFS region.    The authers had much help from the staff of the AVF cyclotron. The authers also thanks the staff at the computer center at the Institute for Chemical Research of Kyoto University and the staff at the computer center of Kyoto University of Education. This experiment was performed at RCNP under program number 10A01 and 12A15.                           REFERENCES 1) H. Fiedeldey, Invited talk to the XI-th International IUPAP Conference on Few Body Systems     in Particle and Nuclear Physics, Sendai, August 1986.  2) Y. Koike, Nucl. Phys. A301 (1978) 411;Y. Koike, Nucl. Phys. A337 (1980) 23.  3) I. Slaus, R.G. Alias, L.A. Beach, R.O. Bondelid, E.L. Petersen, J.M. Lambert, P.A. Treado and     R.A. Moyle, Nucl. Phys. A286 (1977) 67.  4) A. Okihana, Nucl. Phys. A443(1985) 435.  5) J.S. Wesick, P.G. Roos, N.S. Chant, C.C. Chang, A. Nadasen, L. Rees and N.R. Yoder, Phys.    Rev. C32 (1985) 1474.  6) W. Kluge, H. Matthay, R. Schliifter, H. Schneider and K. Wick, Nucl. Phys. A302 (1978) 93.  7) T. Tanabe, J. Phys. Soc. Japan 25 (1968) 21. ( 34 )

³He Breakup Reactions by Deuterons

http://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/77179/1/chd065_1_027.pdf

³He Breakup Reactions by Deuterons

Abstract

Similar works

Full text

Available Versions

Kyoto University Research Information Repository