The azimuthal ({phi}{sub r}) and polar angle ({theta}{sub r}) scattering of projectiles in coincidence with recoil ions has been studied for 0.53 MeV/u F{sup 8+} + Ne. For high degree of ionization of the target we find the resultant transverse momentum of all electrons emitted into the continuum to increase with the number of ejected electrons and to have a direction mostly not co-planar with the scattering plane

Gonzalez, A.

Hagmann, S.

Koch, R.

Kraessig, B.

Quinteros, T.

Schmidt-Boecking, H.

Skutlartz, A.

UNT Digital Library

• J•,, i• .5lh InlcrnationalConferenceon thePhy.,i_.,<,rIli_hb,-C:h.,rvcdI<,n., DOE/ER/13 4 9 1 -- 4"7(;icsscn. September 10-14, 1990DE93 006801Strong Directional Out-of-Plane Scattering in Multiplel()nizing llighly Charged Ion-Atom Collisions• .o o ..)A. GonzNez, l'_ S. Hagmann, _ T. Ouinteros, t's B. Krasstg,- R. Koch)A. Skutlartz, 4 and H. Schmidt-BScking __J.R. Macdcmald L;d_oratory, Kansas State University, Manhattan, KS 66506-2604 USA-I'aKultSt f. Phys!'.<.UnivcrsitSt Freiburg, FRG3Institut f. Kernphysik, UniversitS.t Frankfurt, FRG*E.ast (:ar<,ilna .<-;-atcUniversity, Greenville, NCSNow at ;',,ianne Siegbahn Institut, Stockhom, SwedenAbstract _ ,"y ]/ PPt, r'lhc ._.,inuulh._l ,2,/,_.).k_,,II..... _:,l'l ' ,.) .a .dto 1mi, ,,I iq,q,, Icl,., iii i /ar,_¢_' r r • . .,if"coincidence with lccoii iOI1,'-, !' -;,ct:: -:.:diud I_n 053 Mc\./u 1+' t No. "2....... £--,--_'-@/"For high degree of ioni7.:c! - of '=': target wc find the resultant i //' .-"transverse m()n'icnltm_ (ff a!i . .'::lr,':: ..'mhlcd inl_ lhc c(mlinltm'n I_ ! //'..:J_,.increase wilh lhc nu,nbcr (_ _.:!cd ."zcllons and lo h.vc , dircclion ///''"mostly not co-pkmar with rh :Ca''Crime plane. l/1I. Intr_×luction "'-,. ! {.!'l'5,"_"' - :.i'e-:- -- -',. _go,.,The n_cchanism bv ,vhich ht:.-v cleo:" ,n<_arc simullainCousl,, -'mitred m,-.,_t . i.... "iii coinparativclv slc)',',' co!lisi - =of h!:.}:l'ycharged ions with :iIoII1S h;is Or-ILC;(": ,'*' ;...:'.;1'been of considerable interest..:..",co CxTeriments[l,21 characterizing the / ':'' 'impact l)aramctcr dcpcn(Icnc: ,,f the c::clron emission p:lHcrns in }"_' ..Z'_._ -_'+ Nc revealed si rene ;ii_gular - : p,_l,d ".:2cos of lhc emission l)robabilitics ' '°r"',,,:om,n;Observation of very hlgl_ ll:ng{:'._dina{ :;cclron mOlllelll;I 131and strongpolarization of target electro.". _::atcs ta I showed the strong influence of l.Sg1. E:,T.:rimcntalSet-up.electron nuclear interaction.We reporl ht:re (lil {::.7]tlsiv_: ::'il2aStllelllelllS Of n,iilli-cleclront'niissir, n proll,ibililics IIl<.'/it;lir,.';ivia ;i c<linchlcn('i: l)l:lwccll roLl,ii iorls !1I. Rcsullslind scattered projectiles in 'a':]l del]nod charge states q: detected ;.iiscattering angle (0 v, 4',). T?'..: data show thal the ejected electron Fig, 2 sh.w,,, fnr a fixed pelt r scattering angle 0e=0.2g mrad, themonleliltlnl SIIIIIlIII.Ddm'cr all titiig,_il'lg electrons incrcliscs with azimuthal (<-Dr) dependence of the recoil projccti;c coincidentincreasing degree of i(mizati,'_n and iR nmstly n(m c(}-plaliar ICl lhc probability for selected recoil ion charge states 3 < GR < 7. Wescattering pkmc resulting in strong non co-planar nuclear scat,urine observe for a low recoil charge, qa=3, i.e. 1 electron in the continuumeffects, and two electrons captured into the projectile a si:'.gle peak for¢,,= 180 °. For hiLl,ct recoil charge states, that is a higher multiplicityof electrons emitted into the centinuuna, wc noto that tk a single peakExperiment spills inln two peaks nmvlng away from 180". For qll = 7 4-, lh;li iS forthe emission of 5 electrons, lhc recoil projectile eolncidcnt rate peaksA highly cnllim:ticd beam of .7'.53 M'c\'/u !'_' of lhc .I.R. M;icthmald for 'lh.'-137" :rod ,#r=2230, which ix clearly non-coplanar with theLaboratories EN Tandem into:see,cd with a Negas.iet. The projectiles recoil ions. The analysis of the transverse momentum balance ofwere charge static selected af:er tlm collision and then after 700 cna seallcred projectile and recoil ion allows to deduce the role which lhcflight path detected with a 2-dimensional position sensitive parallel momentum of electrons emitted into the conlinuum plays in theplate aral;roche dclccltu (PPAD) cquipl_ctl with .'_wcdl,.c :lhd strip colli._i_m. Fig. 3 illuslrales lhc transverse momentum balance. Rceollanode. Recoil lOllS iii different charge slalcs (iu cxlraClCd ions ,';.iii lllllv I)c deice,cd if the tr;illsvcrsc recoil liiolncnlilnl p T IlLSelectrostatically from the col[ision zone were dett.-'ted in coincidence within the acceptance cone of the TOF spectrometer. Then, for a fixedwith scattered projectiles in cartesian coordinates (x, y), the recoil ion polar scattering angle a I' + ,3_i' (i.e. projectiles fM!ing into lhcflight time identifying charge s_ates qa (see Fig 1). Due to the small horizontally shaded ring) recoil ions can only be detected inextraction field the detection efficiency of the recoil .'_pectromcler is coincidence with projectiles lit azimuthal angles ¢l,#lgf)*, if PrmiT +Inaxirll;il for rc_.'oll ions going parallel Iii lhc i x axis, i.c. wilh a pu,c'r + p'r = (1, where p'r is the eleclr(m morncnlllm vector summedvanishing y-component of lhc transverse nlonlcnhlnl. A nlaxilllUm in over the transverse momenta of ali emitted electrons.the colncidcnl projectile aThlluihal di.,,trilmlion Ihils will corrc.,,imnd Iii The observation of m.',xima in the ¢i, distribution of recoilrecoils with (pT)y = _.) In off-line analysis for each polar angle a_ projectile coincidcnl events for fixed polar angles then imposesrecoil TOF spectr_ function of the azimuthal angle ¢i' were restrictions on the possible form of the momentum densi b, distributionconstrtlcted from rcc_,, projcclile coincidence evenls recorded on-line of electrons. If for a given degree n,=qa-2 of ionization thewilh t';uic.siall clnuiliu;llc', ('×.)'). ; • ,..,,ii {1 rlr(ili:lllilily di,,lrihuliiul "(ll'.((I.,)l)f,,ll,iw :, .,u,.,.t.mic,lccrease,viii,Jill tI t I I,ll DISTRIBUTION OF THiS DOCUMEN'[ IS UNLIMITED..o._ _... ..... .. ...... .. ,,,,.,........ ........ _.,.,.._,.., ................ ,..,_.._................ ,,,qDISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United StatesGovernment. Neither the United States Government nor any agency thereof, nor any of theiremployees, makes any warranty, express or implied, or assumes any legal liability or responsi-bility for the accuracy, completeness, or usefulness of any information, apparatus, product, orprocess disclosed, or represents that its use would not infringe privately owned rights. Refer-ence herein to any specific commercial product, process, or service by trade name, trademark,manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom-mendation, or favoring by the United States Government or any agency thereof. The viewsand opinions of authors expressed herein do not necessarily state or reflect those of theUnited States Government or any agency thereof.= la = '' I_ ', rl, :: ', = , an: _ .... IIPI ' a ' H ' lr '' '_ ' I_ " ,i_ '=., 44a maxinmm n: lp.]==0 th': fcc,!; projectile coincidcnc. _ickt asfunction of would alv,'avs i'cak ::: or = 180 _ Only, with {;lcr,.'a:fing Py "' ,}n(%',m_an vahlc < lp:!> the observe.5 peak width in lhc recoil '-,ro'.'ctile• : J_ icoincidence distribution ;ts l'uncti,7- of 6, v.'cmld increase tit',:,. . t_\ .! ,", %:5' L-- , - :'J..4.-i\.-- • L ' ' ,._ 'x,e *. .- ;. , -I' - 1 ,'k'_"", _-_. I '5/"- _,___ p....-\ _ ....U_ ,"_' ,,_._ qd-6" _ _moi_':'_p]7c:L .. k'.<.i - , \• Cb .'.- 20ffu_l._J '_m__ %_1,...¢,I"il *''//'" :.--ca, /,_'_, .],,.'., l_;"g'nv.3:" c';'rar,v.'crscc','rl mn,_wm_cnlum,n, u:,mun.balancefo..scaucred projectile, r':,zoil-ionand 5J ro,nea-__,._. , '. J I• , q, 7-I ,,_" //_ Thi- :.':td< l,_ in(tividu;d single clcclr(m crw.r!:,ics bc','aecn 122 ;::'d ,163" [ "'" 4'/" ,." ,V .,,,.,hl.,,,....,'.. .....,,,,',,l,l,,,'h........., '.,l.,I.......l,h.,, ' ",.,, \. cit(. " m-r.:cifil (:,+illcidcIK'c cxpurir:cnts I.%.i,2,2.-t . • , .,-' zz?," IV. Summary,.- ;-.5._ •''" _ " _ i = ! L \Vc have mca._ured inclusive multiclectron cm..lssiono 9.2 BO 270 ,360PROJECT:LE '- !AUTHAL ANGLE prob::hilitics via recoil-scattered projectile coincidences with a d_fincd£C;ll[ ir;:lg plilllC. \Mc filld lh;It the tol;ll transverse clTclron ml)n: .'nlum_., 7EGREES) incrc,:scs v,'ith tlm numbcr of electrons emitted h_:o the con'!.-'luum.We also firdthat at very small scaucring angles electrons are. c.mittedFig 2.. l(ccoil-projc',llc coincidcn: dis:r'_-.:ion for different recoil cha:;c states as non-isotroi)icall.v with respect to "he scattering plane giving -isc tofunctionof ep for p3;arscatteringa.".g!ce-.=3.28mradof projcclilcs, stro;:Z OVt of plane scattering of the projectile.The observed maxima a: :,,#-180° c;tn only bc ,':'lain,cd if Acknowlcdgcmentsalready the distribution l_(:p,[) :=as it maximum at [p_ ---(1. Thedeviation of 6p from 180° degree i.: therefore a direct measzrc of the This ',york was supported by: th(; Division of Cl',zmicalmean electron memcntum ,,'ecmr - I. Scier.ces, Office of Basic Energy Scicnce, Office of Energy Research,All c'.qlinlillt: lth life nl:l:zr.ituilc nf lilt: Ir;ul_,vcl_,- (']cclr(m I,l.,'q.i)up;_llmcnl ()f I!ncrT,y; and Iv,' l)cutsch(" I: u':;c :t U'sy,c t c n';(' t I['llllOlllCntaC;lllJlcderived :ix foIi:,'.vs: ;tr the azimulh ,1,,. '.vhcrc tlm DF(J. Germany.coincident scattered projectile d{str!bution has ;t maxinmm, we havcp V p T p V 0(1) Proj,x + Rc':..:,: 4. c,x = Rcfcrcncc._p 'r p V = 0"(2) Proj,y + 0 -- e,y 1. A. S':utlartz, S. Hrtgmann Phys. Rcv. A ZS, 3268 (1983).2. H. Schmidt-BC_cki,_g, A. Skutlartz, S. I-lagnxmn. Phys. Lctt. t22A,Eq. (1) will not be used at tt.is tim:: due to large uncert;lin:ics in the 42l (1987).p "r (see also Fig 3). Eq. (2) roads for smalldctermination of Rcc,x 3. R. Schuch, H. Sch6nc, S.Datz, Phys. Roy. Lctt_ 60, 925 (1987).scattering angles 4. R. Docrner, J.Ullrich, H. Schmidt-B6cking, R. Olson, Phys. Rev.• , ,,,._ . p T Lett. 63, 14"/ (1989).(3) PProj t OF, ,sin :3_,. ' e,y = 0, 5. B.Kriissig, S.Hagmann, A.Gonzalez, and T.Quinteros (to bepublished).p Twe then derivewhere Pp,,.,i_is the incident projectile momentum, e,y;is hv.ver hound for lhc elcctr(m tr;tns'.,ersc momenlun_ .: Ir.Vl:, [;,.u.].Table 1.0 p= 0.2,Smrad 0,.= 1.1mrad(I. ", < ]P,Tt > <li',' I:"5 3 9 12O 4 18 187 5 30 248 6 35 36,, .bIii

Strong Directional Out-of-Plane Scattering in Multiple Ionizing Highly Charged Ion-Atom Collisions

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Strong Directional Out-of-Plane Scattering in Multiple Ionizing Highly Charged Ion-Atom Collisions

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