The APS Transfer Line from Linac to Injector Synchrotron.

Transcription

1 , The submtted mclnu;..crpt has been authred by a cntractr f the U. S. Gvernment under cntract N. W ENG 38. Accrdngly, the U. S. Gvernment retans a nnexclusve, ryalty-free lcense t publsh r reprduce the publshed frm f ths cntrbutn, r allw thers t d s, fr U. S. Gvernment purpses. 1S-163 March, 1991 The APS Transfer Lne frm Lnac t njectr Synchrtrn. R. K. Kul and E. Crsbe Argnne Natnal Labratry Ths nte descrbes the lw-energy-transfer-lne desgned fr the APS. The lw energy transfer lne cnsttutes tw transprt lnes. One f these lnes runs frm lnac t the pstrn accumulatr rng,als called "PAR", and s m lng. The secnd part f the lw energy transprt lne runs frm the "PAR" t the njectr synchrtrn and s abut m lng. The abve length ncludes tw quadruples, a bend magnet and a septum magnet n the njectr synchrtrn (see fg. 1 and table 2). The pstrn bunches f emttance EN = 1.1mm - mrad arrvng at the end f the lnac at 45 MeV have twss parameters as gven by N assr 1 ax = 1.688, f3x = , a y = , f3y = The transfer lne (see als Yn and Crsbe 2 ) frm lnac t "PAR" s made up f ten quadruples and ne bendng magnet B4 (see fg.l). The bendng magnet bends the beam by.2 radans twards the septum magnet n the "PAR". The fve quadruples n the regn between the bend magnet and the septum magnet n the "PAR" gve a phase shft f 27r radans, n rder t get dspersn free bunch at the end f the septum magnet. The twss parameters at the end f the lnac gven abve are matched wth the twss parameters and the dspersn functns at the end f the septum magnet, n the "PAR" lattce structure. These parameters at the end f the "PAR" septum are gven by ax = , f3x = , a y = , f3y = 8.241, rtx =., rtf x =. The matchng prcedure was carred ut usng cmputer cde "COMFORT". t shuld be mentned that the 2.9 m f dstance between the last quadruple and the septum magnet n the "PAR" s mre r less frced n us because f the cnsderatns f the

2 2 avalable space n that regn. The layut f ths regn f the transfer lne s shwn n fg. 1. Detals f the magnet dmensns and ther strengths are gven n table 1. The rder f the magnets s the rder n whch they appear n the transfer lne as ne traverses frm the lnac t "PAR". The j3 functns n the hrzntal and the vertcal plane alng wth the dspersn functn, f/, n the hrzntal plane are shwn n the fg. 2. The maxmum j3y s apprxmately 2 m and ccurs at the quadruple befre the bend magnet. The maxmum value f the j3x s abut 16 m. n addtn t the abve elements, the lnac t "PAR" part f the lw energy transfer lne cntans eght steerng magnets and seven beam pstn mntrs. Of the eght steerng magnets fur are fr steerng n the hrzntal plane and the remanng fur are t be used fr steerng n the vertcal plane. Smlarly, ut f the seven beam pstn mntrs three are t be used fr dagnstcs n the hrzntal plane and the remanng fur fr dagnstcs n the vertcal plane. The relatve pstns f these steerng magnets are als gven n fg. 1. The calculatns fr the strength and the dmensn f these steerng magnets was carred ut usng a cmputer cde lcally develped fr ths purpse. Hwever the cde was tested fr the calculatn f twss parameters aganst the "COMFORT" run. Tw sample plts fr the partcle trajectry alng the hrzantle drectn fr a gven kck, btaned by the abve cmputer cde are gven n the fg. 4 and fg. 5. The secnd part f the lw energy transprt lne carres the pstrn bunches frm the "PAR" septum t the njectr synchrtrn. Agan the energy f the pstrn bunches s abut 45 MeV. Ths sectn s made up f tw bend magnets (B1, B2), and eleven quadruples jnng the "PAR" septum magnet "B3" n the ne end and the njectr synchrtrn septum magnet n the ther end. The bend magnet B2 bends the bunch, cmng frm the "PAR" septum magnet (bend angle f -.2 radans) thrugh an angle f.2 radans. The sectn between the bend magnet B2 and the septum magnet B3 S the same as the sectn between the bend magnet B4 and the septum magnet B3. t prduces dspersn free beam n the regn between B2 and B1. The next sectn between bendng magnet B2 and the bendng magnet B1 has fur quadruples whch can be used as tunng quadruples fr tunng n t fur twss parameters n the vertcal and hrzntal drectn. The bend magnet B1 bends the beam at an angle f radans apprxmately twards the njectr synchrtrn septum. There are tw quadruples n

3 3 the sectn between the bend magnet B1 and the njectr synchrtrn septum, whch are arranged such that the bunches enterng the njectr synchrtrn are dspersn free at the end f t.he dple magnet B (see Table 2). The detaled layut can be seen n fg. 1, and the relatve pstns the dmensns and the strengths f the magnets are gven n table 2. The maxmum value f the /3 functn frm B2 t the njectr synchrtrn septum s abut 26 m. n desgnng the transfer lne frm the "PAR" t the njectr synchrtrn, sme part f the njectr synchrtrn s ncluded. The twss parameters gven by the njectr synchrtrn lattce at the begnnng f the drft 1 (see Table 2.) are matched wth the twss parameters gven at the begnnng f the "PAR" septum magnet gven abve (sgn f the a functn must be reversed), thrugh the transfer lne. Agan, the cmputer cde "COMFORT" was used fr matchng purpses. The twss parameters at the pstn 1 are gven bellw. The sgn f the a functn crrespnds t the mtn frm "PAR" t the njectr synchrtrn. ax =.462,/3x = ,ay = ,/3y = The detaled frm f the /3x, /3y and the 17x s gven n the fg. 3. n addtn t the abve cmpnents ths part f the transfer lne cntans sx steerng magnets and seven beam pstn mntrs. Out f the sx steerng magnets, three are used fr steerng n the hrzntal drectn and the remanng three n the vertcal drectn. Smlarly, f the seven beam pstn mntrs fur are t be used fr mntrng the hrzntal pstn and the remanng three fr mntrng the vertcal pstn. The maxmum B =.12 T.m fr these steerng magnets. These calculatns were carred ut usng, as mentned abve, a lcally develped cde. The detals f ther pstns and ther parameters are gven n the table 2..

4 4 1. References 1. AlE N assr, Prvate cmmuncatn. 2. M. Yn and E. Crsbe, APS nte LS-119 (1988).

5 Table 1: LTOP PAR..'.},ETERS (,1,3 11eV. Bp = 1.33 T-mete" -Pstve K, means hrzntal defcussng. ) nput Twss Parameters:a, == 1.688, f" == , a, = , f, = 6,6888 Output Twss Parameters:' z == -.919, f, == 2,1261,, == ,f y == S T en'7th --=>.-... u r l>lamet ) Stren2th u u K, == B'/Bp[m]-',p[m] Th e t a 1 Thta2 e DRFT:1 l.b" Stee1'7lg y DRFT:O.1 QUAD:Q DRFT: QUAD:Q2,3 -D, llS DRFT:3,1 Stee";7lg,,3.,18 DRFT: QUAD:Q DRFT:Ol 2.G1 BPMy DRFT:Ol.1 QUAD:Q l DRFT:O ).1 Sta1'7lgy..).18 DRFT:O.) 1.';S697 DRFT:3.1 QUAD:Q.),3 2.9,3617 DRFT:6.1 Steerng,.3.18 DRFT:5.53 SEt:ND:B.1.2 DRFT:7.8 DRFT:7.1 QUAD:QU.3 < DRFT:9.1 Steer'ngy.,3.18 DRFT:9.7,3 DRFT:9.1 QUAD:Q DRFT:9.1 Steerng,.3.18 DRFT:9.,,3 BPMy DRFT:9.1 QUAD:Q DRFT:9.1 Seedng DRFT:9.7.) DRFT:9.1 QUAD:Q DRFT:9.1 Star7lg,.3.18 DRFT:9 O.S ) QUAD:Q DRFT:8.3 BPMy DRFT:8 2, SEt:ND:B3.1 -D, D.O -.2

6 Table Z: PTOB PARAETERS (1.3 MeV. Bp = 1.33 T-meter, -Pstve Kl means hrzntal defcnssng. ) nput Twss Paramet.ers:a. = 1.688,;3. = , a, = ,;3. = Output Twss Paramet.ers",'z = -.9,19,;3z = , "", = -.2,13,;3, = cement Lengh 8 r Aagnet Strength Kl = B/Bp[m]-2,p[m] Theta lheta2 S8[ND:B3 O DRFT:OH QUAD:Q :57169 DRFT:O3.9 BPM. DRFT:O3.1 QUAD:Q :)631 DRFT:12.1 Steel'ng DRFT:O2.7:5 BPM. DRFT:12.1 QUAD:Qll.3 ' DRFT:Oll.1 Steerng..3.Q7 DRFT:Oll.7 3 DRFT:Oll.1 QUAD:Q DRFT:OlO.1 Steerng.. ).133 DRFT:O.73 BP}.fy DRFT:O.1 QUAD:Q DRFT:9.1 Steerng DRFT:9.7.3 SBt:ND:B2 O..t.2 DRFT:8E.3 BPA. DRFT:8E.1 QUAD:QS DRFT:8D.6 QUAD:Q DRFT:8C Steerng DRFT:8c.1 QUAD:Q DRFT:SB. 3 BPM. DRFT:8B.1 QUAD:Q DRFT:8A.1 Steerng,.3.13 DRFT:8A.1:) SBt:ND:Bl,, DRFT:O, DRFT:7.1 QUAD:Ql.3 -l DRFT:6.9 QUAD:Q DRFT:3.9 (nsde Bst.er) (nsde Bster) SBt:.VD:SEP.8.267;)1 DRFT:Ol l.3 3 QUAD:Q DRFT:3.311:) SBt::'D:B DRFT:2.:)11.) QUAD:Ql ) DRFT:Ol cl.l

7 X= y= X= y= // Z, X= y= X= y= X= y= " 9 1 ' : 8r ---e OS 12 KJ=--. 'a 8L-,88L-,8 13 " E" BJ,',8 OJ -"cor----- : : 8.r---::/ _ '2 " " 9 J B -- X=, y= (L1NAC WORKNG PONT) X= y= a-brad <EY 6 VERTCAL apm? HORZONTAL BPM T VERT STEERNG MAGNET HORZ STEERNG -.L MAGNET FGURE 1. LOVV ENERGY TRANSPORT LNE FG

8 let <t... '-'-' l J l 1.. t' - ct..j :l.j G a -z <t. ) ('4 (,) w l- z 14 :E...l v, JJ Cl L:.. w...-{ hl <) :J. H 1=- W 11- c C) 'Z -1 r: (j d l- ([ 1 1 1: 1 lu 1.4: z t1, G G G,:J G...-{...-{,;] 1 rr: w

9 -.: T..., t t rl l Y F t CJ P, OJ t r-1. b.-. '1' "--1 6.',... en r:-1 1 " '-'-', }- J, r t' a. v j'j G (', '1... G H a: - Lt. a: 1 Q t=j f. j t h. L2.J ' Jl (J,... n cr: w. r t,, ;, " ft1..-;, CO Y 1 "1 1 J j,, q J CL j w 1::' <t ;- ;}- 'V 1 1 le, CJ, (1 E Vl ('Y t

10 X/Xprme VS DSTANCE. (Kll.,a:Xl =.1) - -u----cl ---L--AT--D DlJ-ll...-O lj )_ / /. *- -- (:) / - ; , (). ) *' **" " f,,, *E-'?f';; CD -,' Q " 1 1 u t " b b CD *E----** *E-"* * LEGEND * XlXPRME *E t- O 2 4 L , T , ' 1 f L 1 _ ' , , _._._-_._... _ :.;=======:====================

11 X/XPRME VS DL_ range, 'l- [l D -lr uj]_-ljj.le]---lj L_E3-._[LE=--=-3Tr ----1'. Qv f1e *,,' '., - ',' 1 ''T '".'**' - - "fl *"*-*- ' 1 1,1 1 ***-*, '. '. *'* *-. 9tCh ; cp "'... & (;) *,---",* C & ' ' P4 9. * LEGEND'" -' _... _.. x *' XPRME