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TT2 ION LOW- OPTICS COMMISSIONING. Optics performance with QFO205 maximum current limited to 330 A (instead of 450 A) and with QKE58 on/off. C. Carli, D. Manglunki, M. Martini. Contents. Low- insertion issue Low- insertion and TT2 end matching (nominal optics, QKE58 on)
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TT2 ION LOW- OPTICS COMMISSIONING Optics performance with QFO205 maximum current limited to 330 A (instead of 450 A) and with QKE58 on/off C. Carli, D. Manglunki, M. Martini Contents • Low- insertion issue • Low- insertion and TT2 end matching (nominal optics, QKE58 on) • Optics measurements at SEM-fils (nominal optics, QKE58 off) • TT2 entry tracking back to assess the low- insertion (nominal optics, QKE58 off) • Emittance measurements (nominal optics, QKE58 on) • New low- insertion and TT2 end re-matching (new optics, QKE58 off) • Optics measurements at SEM-fils (new optics, QKE58 off) • Emittance measurement (new optics, QKE58 off) • TT2 entry tracking back to assess the low- insertion(new optics, QKE58 off) • Mismatch measurement with nominal (QKE58 on) and new (QKE58 off) optics • TT2 future studies
Low- insertion issue Expected max emittance increase after stripping0.12 m (initial 0.7 m) Final emittance<1.0 mm Raised to 0.25 m withIQFO205=330 A instead of the nominal IQFO205=437 A QFO205 max current=330 A (initially required max 450 A) Ion beam QFO135 QFO105 QFO165 QFO205 QFO215 STRIPPER QDE120 QDE150 QDE163 QDE180 QDE207 QDE210 QDE213 QDE217 QDE220.S 6 individual supplies: QDE210 and QFO215 disconnected from strings 6 individual supplies: QDE210 and QFO215 disconnected from strings 6 individual supplies: QDE210 and QFO215 disconnected from strings 6 individual supplies: QDE210 and QFO215 disconnected from strings 6 individual supplies: QDE210 and QFO215 disconnected from strings 6 individual supplies (QDE210 and QFO215 disconnected from strings) b ‘s reduced by a factor5 0.8 mm Al stripper • Ion kinetic energy 5.88 GeV/u (=7.244) • Br54+= 86.7 Tm (before stripping) 26.0 GeV/c eq. protons • Br82+= 57.1 Tm (after stripping) 17.1 GeV/c eq. protons New quadrupole strings: QDE210.S QDE220.S QFO215.S QFO225.S TT2 low- insertion (6 additional quadrupoles for optics matching)
Low- insertion issue (1)The PS kick enhancement quadrupole QKE58 will not be used in the future (2) from1995 emittance measurement at 4.25 GeV/u new stripper at 70 m from TT2 entry past stripper at TT2 end (302 m) 82 0.8 mm 7.2437 0.0625 mrad 0.9906 89 mm (Al) Multiple scattering root mean square angle 2086.7475 GeV/c Growth in normalised rms emittance due to stripping
Low- insertion and TT2 end matching (nominal optics, QKE58 on) “low-” at stripper “low-” at stripper nominal optics QKE58 on TT2 low- optics with IQFO205=330 A instead of 437 A (converter limitation)
Low- insertion and TT2 end matching (nominal optics, QKE58 on) nominal optics QKE58 on H=8.9 m V=8.1 m Stripper (69.6 m from TT2 entry) TT2 “low-” optics with IQFO205max=330 Ainstead of 437 A
Low- insertion and TT2 end matching (nominal optics, QKE58 on) (1)new quad,(2)new supply,(3)2 quads out of 13 are of type QFS Initially 437 A with IQFO205max=500 A
Optics measurements at SEM-fils (nominal optics, QKE58 off) Needed to derive D’H,V from the transfer map Needed to derive D’H,V from the transfer map nominal optics and QKE58 turned off Transfer map from MSG257 to MSG267 15 Nov MD Optical parameter measurements using the nominal opticsderived with QKE58 on IQFO205=330 A
TT2 entry tracking back to assess the low- insertion (nominal optics, QKE58 off) nominal optics and QKE58 turned off “low-” from track back (foil scattering ignored) “low-” from track back (foil scattering ignored) Initial conditions at MSG257 (measurement with QKE58 off) New initial conditions at TT2 entry TT2 low- optics with IQFO205=330 A: Tracking back using SEM-fil data
TT2 entry tracking back to assess the low- insertion (nominal optics, QKE58 off) nominal optics and QKE58 turned off Ion beam (reverse direction) Optics at TT2 entry (162.1 m from MSG257) Scattering through the foil ignored Optics at MSG257 Stripper (92.4 m from MSG257) TT2 low- optics with IQFO205=330 A: Tracking back using SEM-fil data
Emittance measurements (nominal optics, QKE58 on) early beam intensity Hn(1)=0.71 m nominal optics QKE58 on 27 Oct MD TT2 horizontal SEM-fil profiles with IQFO205=330 A
Emittance measurements (nominal optics, QKE58 on) early beam intensity Hn(1)=0.60 m nominal optics QKE58 on 27 Oct MD TT2 vertical SEM-fil profiles with IQFO205=330 A
Emittance measurements (nominal optics, QKE58 on) nominal optics QKE58 on 27 Oct MD TT2 magnet currents – Ion beam on dump D3 (IQFO205=330 A)
Emittance measurements (nominal optics, QKE58 on) early beam intensity Hn(1)=0.42 m Geometric blow-up Stripper in The QFO205 power converter was especially boosted for this measurement campaign and a corresponding low- optics was devised nominal optics QKE58 on 1 Nov MD TT2 vertical SEM-fil profiles with IQFO205=400 A
Emittance measurements (nominal optics, QKE58 on) early beam intensity Hn(1)=0.33 m Geometric blow-up Stripper out The QFO205 power converter was especially boosted for this measurement campaign and a corresponding low- optics was devised nominal optics QKE58 on 1 Nov MD TT2 vertical SEM-fil profiles with IQFO205=400 A
Emittance measurements (nominal optics, QKE58 on) (1) from1995 emittance measurement, scaled with the proton optics ’s (H=30.8 m, V=39.1 m) at new stripper location (2) 20 Nov 2006 emittance measurements (3) Quadrupole currents scaled downstream the stripper The QFO205 power converter was especially boosted for this measurement campaign and a corresponding low- optics was devised 1 Nov MD nominal optics QKE58 on Emittance measurements at SEM-fils with stripper IN/OUT (QKE58 off)
New low- insertion and TT2 end re-matching (new optics, QKE58 off) “low-” at stripper (scattering ignored) “low-” at stripper (scattering ignored) new optics QKE58 off Initial conditions at TT2 entry TT2 low- optics with IQFO205=330 A instead of 437 A (converter limitation)
New low- insertion and TT2 end re-matching (new optics, QKE58 off) new optics QKE58 off H=10.2 m V=6.9m Stripper (69.6 m from TT2 entry) TT2 “low-” optics with IQFO205max=330 A instead of 437 A
New low- insertion and TT2 end re-matching (new optics, QKE58 off) Initially 437 A with IQFO205max=500 A
Optics measurements at SEM-fils (new optics, QKE58 off) Needed to derive D’H,V from the transfer map Needed to derive D’H,V from the transfer map new optics and QKE58 turned off 16 Nov MD 26 and 21% differences between linear and quadratic fits 26 and 21% differences between linear and quadratic fits Transfer map from MSG257 to MSG267 Optical parameter measurements using the new opticsderived with QKE58 off IQFO205=330 A
TT2 entry tracking back to assess the low- insertion (new optics, QKE58 off) new optics QKE58 off “low-” from track back (foil scattering ignored) “low-” from track back (foil scattering ignored) Initial conditions at MSG257 (measurement with QKE58 off) Latest initial conditions at TT2 entry TT2 low- optics with IQFO205=330 A: Tracking back using SEM-fil data
TT2 entry tracking back to assess the low- insertion (new optics, QKE58 off) new optics QKE58 off Ion beam (reverse direction) Optics at TT2 entry (162.1 m from MSG257) Scattering through the foil ignored Optics at MSG257 Stripper (92.4 m from MSG257) TT2 low- optics with IQFO205=330 A: Tracking back using SEM-fil data
Emittance measurements (new optics, QKE58 off) early beam intensity Hn(1)=0.88 m Geometric blow-up new optics and QKE58 turned off 16 Nov MD TT2 horizontal SEM-fil profiles with IQFO205=330 A
Emittance measurements (new optics, QKE58 off) Vn(1)=0.77 m new optics and QKE58 turned off 16 Nov MD TT2 vertical SEM-fil profiles with IQFO205=330 A
Emittance measurements (new optics, QKE58 off) Vn(1)=0.77 m new optics and QKE58 turned off 16 Nov MD TT2 longitudinal profile with IQFO205=330 A
Mismatch measurement with nominal (QKE58 on) and new (QKE58 off) optics IQFO205=330 A measured from lattice rms beam size
TT2 future studies • Upgrade the of QFO205 power converter to deliver the 450 A maximum current required for the nominal low- optics (to keep the emittance growth after stripping within the emittance budget, especially for the nominal beam) • Revise the low- optics setting to fit with the new initial optics parameter values at TT2 entry (PS exit) following the “removal” of the kick enhancement quadrupole QKE58 power converter • Transfer the ion beam to the SPS (2007) and measure the effective emittance growth due to stripping • …