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PSB and PS optics

PSB and PS optics. O.Berrig HSC/ABP. 18/6/2014. BOOSTER injection and extraction lines. BTP. BT. BI. LTB. LT. The BT and BI lines are, in my opinion, the most difficult and the second most difficult transfer lines in the whole of CERN !!!. BOOSTER injection and extraction lines.

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PSB and PS optics

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  1. PSB and PS optics O.Berrig HSC/ABP 18/6/2014

  2. BOOSTER injection and extraction lines BTP BT BI LTB LT The BT and BI lines are, in my opinion, the most difficult and the second most difficult transfer lines in the whole of CERN !!!

  3. BOOSTER injection and extraction lines • Last year and the start of this year, required a complete update of the BOOSTER injection and extraction lines because we needed to install YASP • YASP = Yet Another Steering Program. • YASP automatically measures the beam position, and if the beam is not in • the center of the vacuum chamber, it actives some corrector magnets • (DVT/DHZ) to push the beam to the middle. • YASP is only used for transferlines e.g. when transferring the beam from • the BOOSTER to the PS. YASP is not used inside an accelerator; in this case • we use a program called an “orbit correction program” • We (B.Mikulec/V.Raginel/G.P. Di Giovanni/yours truly) were in a terrible time trouble this year because - at the same time - the survey group required surveys for the LINAC4 and LINAC4 transferline; But this is another story.

  4. BOOSTER injection and extraction lines • Why are the BT and BI lines so difficult? • The main reason is that these lines consists of 4 lines that are placed on top of each other. And therefore, the position of an element is given as the length from the start of the line. This is not the type of position the MADX needs; MADX needs beam positions – also called “s” positions – that are measured along the beam path. • Further more, the positions from the start of the line are “middle positions” i.e. related to survey positions, while the “s” positions are related to the deflection points*. We have three clear definitions: • The length from the start of the line to the middle point of an equipment = “mechanical center position” or just “mechanical position” • The length from the start of the line to the deflection point of an equipment = “mechanical deflection point” or just “deflection point” • The position of the equipment along the beam path = “s-position” * The deflection point is the crossing point between two straight lines

  5. BT4.BVT10 BOOSTER injection and extraction lines BT4.SMV10 BT4.QNO10 BT4.QNO20 BT4.KFA10 Mechanical center position of BT4.BVT10 Mechanical centerposition of BT4.KFA10 The drawings provide the mechanical center positions of the elements – these are the middle positions!!!

  6. The middle position of the long bending magnet BOOSTER injection and extraction lines Height of the BT line The middle position of the short bending magnet The deflection point is unchanged SHORT BENDING MAGNET LONG BENDING MAGNET Changing the length of a bending magnet has huge consequences for the calculation of the position of the bending magnet !!! Sketch of the BT line, with strongly exaggerated bending angle Length along the BT line L/2 L/2 Projections along the length of the BT line

  7. Calculate ANGLES BOOSTER injection and extraction lines ANGLES = func(deflection point, geometrical data). E.g. http://cern-accelerators-optics.web.cern.ch/cern-accelerators-optics/BTBTPBTM/AugmentationLacceptance_PSB_PS.pdf Deflection point Do the following process for all equipment with a bending angle: CalculateSEQUENCE files: BT1.seq, BT2.seq, BT3.seq and BT4.seq E.g. http://project-ps-optics.web.cern.ch/project-PS-optics/cps/TransLines/PSB-PS/2014/cmd/matching_BT_line/BT4.madx CalculateSURVEY files: BT1.sur, BT2.sur, BT3.sur and BT4.sur Middle position from drawing = Middle position from survey ? Middle position from drawings Modify deflection point NO FINISH YES

  8. BOOSTER injection and extraction lines • Other difficulties of more general art: • The position information comes from: drawings, survey files, old madx files, pictures and measurements on site. • These positions are often contradictory – what to do? • Recently it was decided to base all calculations on the drawings! • Overruled in special cases, with survey constraints • Drawings are often difficult to get. CDD drawings often not detailed enough. Often we have to go to the equipment specialist and ask for detailed drawings. Equipment like septa and kickers are inside tanks and requires detailed drawings of the interior. • In general, most time is used to find and verify data. • If wrong data is found, feedback is always given at the source. • In recent years, big progress has been made in obtaining data: • NORMA – database for magnets • EDMS – database for many things, drawings (CDD phase out), reports … • Layout database – equipment information and position (ECR) • GEODE – Survey database (it is now working well) • http://cern-accelerators-optics.web.cern.ch/cern-accelerators-optics/ • Panoramic photos e.g.: Straight Section 5

  9. BOOSTER injection and extraction lines • Other difficulties of more general art: • Survey uses fix points to align the different transferlines. A fix point is a deflection point between two transfer lines. E.g. for LINAC4 The precision of SURVEY is 10 um, so the equipment positions are always with 1 um precision in order to avoid rounding errors

  10. BOOSTER injection and extraction lines • Another specific difficulty of the BT and BI lines: • The DVTs and the quadrupoles in the BT and BI lines are used as bending magnets. I.E. even though a DVT is normally defined as a corrector magnet, it is used to volutary bend the beam. Also quadrupoles in both lines are offset in order to create a bending magnet (feeddown). Unfortunately MADX cannot model a voluntary displacement of a quadrupole; in the sense that the transverse position after the quadrupole should be zero – today it is proportional to the offset. • Today we model the offset quadrupoles as bending magnets with a • quadrupolar component. However, the optical functions depends strongly • on whether we use a model of an offset quadrupole or a model of a bending • magnet with a quadrupolar component. Since YASP already worked last year • for the BT line – where the offset quadrupoles were modelled as bending • magnets with a quadrupolar component – then we have probably been lucky • to choose a model which is not too wrong. • Some effort should go into understanding the fringe fields better for • combined function magnets.

  11. PS optics The PS optics work consists of four stages: Gathering all the updates Implementing the updates Testing and verifyring Entering the 2014 files into the SVN backup system The gathering of the updates have this year been done by the T. Birtwistle who is in charge of the layout database for the PS. It took him a week. In the previous years this was done by the ABP, and it took 2-3 weeks. The reason for the large improvement is that the ECR (equipment change request) system is now starting to work. The ECR system tracks the changes. ABP will still continue to work closely together with the layout database people to document changes and to corrects inaccuracies.

  12. PS optics The implementation of the updates was this year done by S.Gilardoni. The changes are documented here: \\cern.ch\dfs\Users\b\berrig\Public\PS_changes_2014.docx These updates were already implemented the layoutdata base, and then copied. The huge majority of the changes are ”name” changes according to the ECR: Engineering/Technical Note Document PS-E-EN-0005 ver.1.0 Released"PS Ring Electrical Circuits Defined in the LayoutDatabase"by Thomas Birtwistlehttps://edms.cern.ch/document/1375156/1.0 The more substantial changes are (these changes are marked in red in the document: PS_changes_2014.docx): Remove: PR.QCOMP01 Remove: PR.URS032 Install: PR.DHZOC05 Install: PR.XSK10 Install: PR.TPS15 Remove: PR.DLH15 Remove: PR.QNT15 Install: PR.ODN52.B Install: PR.BPM54 Install: PR.XNO60 Remove: PR.QCOMP67 Install: PR.BPM68 Install: PR.BWSH68 Install: PR.ODN70.A Install: PR.BQL72 Install: PR.URL76 Install: PR.XNO94 Install: PR.QTRTB99.A

  13. PS optics • In the last few days, the following verifications were done: • PR.DHZOC05 : D210 , AT = 0.1, KICK := +DHZ60 * CC210;  Is the current correct? • (the position of this corrector is awaiting confirmation from SURVEY) • ! MTE octupoles: calibration coefficient frommeasurement of M. Buzio • OMTE : MULTIPOLE; CCMTE:= 9.03/(BRHO); !OMTE design • CCMT1:= 9.17/(BRHO); !OMTE meas. order 1 • CCMT2:= 6.19E-3/(BRHO); !OMTE meas. order 2 • CCMT3:=-1.03E-5/(BRHO); !OMTE meas. order 3 • ! OCT39,OCT55: ideallinearcurve • !K3OCT39:=Ioct39*CCMTE; • !K3OCT55:=Ioct55*CCMTE; • ! OCT39,OCT55: calibration curve • K3OCT39:=Ioct39*(CCMT1 +abs(Ioct39)*CCMT2 +(Ioct39^2)*CCMT3); • K3OCT55:=Ioct55*(CCMT1 +abs(Ioct55)*CCMT2 +(Ioct55^2)*CCMT3); • The length of sextupole 608 and octopoleMONDAFWP are being investigated.

  14. PS optics In the last few days, the following verifications were done: The type of PR.QTRDB29   is  Q406. In the LDB – in the section for automatically generating the sequence – it is set to 408. Will be looked into later. There are TV cameras of both the septa i.e. PI.BTV26 and PI.BTV42 New strengths for the pole face windings: pfki1f = -0.00241583848 ; pfki2f := 0.0396084929 ; pfki3f := -0.0600299313 ; pfki1d = 0.002337600639 ; pfki2d := -0.0453516710 ; pfki3d := -0.2255528890 ; New bumper strengths for bump 16: bsw16a = 367.3718203 ; bsw16b = 0 ; bsw16c = 107.6935616 ; bsw16d = 45.77380721 ; bsw16e = 101.525049 ; bsw16f = 119.8731841 ;

  15. PS optics In the last few days, the following verifications were done: New currents for the MTE sextupoles and octupoles (and the landau octupoles should be set to zero at the MTE extraction): Ixct39 := 110; Ioct39 := -30; Ixct55 := 60.09; Ioct55 := 35; Iode := 0; For the MTE, the change of horizontal tune from 0.245 (set withthe PFW) to (movement "simulating" the resonancecrossing) 0.252 with the q-low: iqf= 2.254078691 ; iqd= 1.188420453 ;

  16. PS optics Further work to be done for the PS: It should be discussed with the PS superattendant any other changes are known The previous 9 points should be implemented in the operational files: http://project-ps-optics.web.cern.ch/project-PS-optics/cps/Psring/models/2014/madx/ The TT2 files should be updated/verified and tested

  17. Conclusions: • The YASP implementation in the BI line was fast, because much of the software from the BT line could reused. • Many groups have in the last years developed new tools that helps in finding information: • NORMA – database for magnets • EDMS – database for many things, drawings (CDD phase out), reports … • Layout database – equipment information and position (ECR) • GEODE – Survey database (it is now working well) • Panoramic photos e.g.: Straight Section 5 • The ABP website for optics is regularly used in many groups: • http://cern-accelerators-optics.web.cern.ch/cern-accelerators-optics/ • The updates to the PS are now done by people responsible for layout database. This process is now much faster thanks to the ECR system! • More updates for the PS still needs to be implemented • TT2 needs to be updated and verified. TT2 is part of PS

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