ATS round and Flat MDs S. Fartoukh (BE/ABP - PowerPoint Presentation

Slide1

ATS round and Flat MDs

S. Fartoukh (BE/ABP), M. Solfaroli (BE/OP) on behalf ofthe OP, OMC, Collimation, LBDS Lumi, Beam-beam, Instability & ADT teams

17/05/2018

S. Fartoukh, LSWG, 17/05/2018

1

MD 3270:

Round optics with large telescope deployed in the Ramp

MD 2148:

Flat Optics 60/15 cm continuation

MD 3270

- Round Telescopic opticsMD setup and readinessActivity for MD1 and wish list for MD217/05/2018S. Fartoukh, LSWG, 17/05/20182

MD set up & readiness (round optics)

Brand new ramp calibrated for Run III (BBLR mitigation and Landau damping @2.2E11 p/bunch)“CRDS”: combined ramp and double squeeze Nominal injection optics Reach b*= 2 m as soon as possible (ideally 3 TeV vs. 5.3 TeV presently) Deploy the telescope targeting a tele-index of rTele~ 3  b*= 67 cm in the end of the ramp

At 6.5 TeV, reactivate the pre-squeeze sequence down to

The optics assemblies are not ready yet, nor the

hypercycle

(needed for MD1) & the new TCP/TCSG/TCT functions (needed for MD2).

17/05/2018

S. Fartoukh, LSWG, 17/05/2018

3

Tele-index

r

tele

(i.e.

b

*

pre-squeeze

/

b*collision)

MO tune spread amplification vs. tele index, relative to any pre-squeezed optics

> 400% for a tele-index of 4

(typical HL-LHC)

~ 25 % @

r

Tele

= 1.6 (LHC2018 @ b*=25 cm)

~ 280 % @

r

Tele

= 3

(target for Run III)

MD activities (round optics)

MD1 (10 h) with probe, flat machine and coarse collimator settings Demonstrate the OP mechanics Optics measurements and corrections in the EoR and EoS If time permits achieve a second cycle with X-angle & optics measurement on the fly in the ramp and EoS MD2 (1-2 shifts) with 3E11 Ref orbit and collisions (4 IPs) Loss maps, EoR

and EoS

Aperture validation @ 30 (or 25) cm

Octupole function and polarity

17/05/2018

S. Fartoukh, LSWG, 17/05/20184

MD 2148

- Flat Telescopic opticsMD setup and readinessActivity for MD1 and wish list for MD2Expected difficulties (in addition to optics correction)17/05/2018S. Fartoukh, LSWG, 17/05/20185

17/05/2018

S. Fartoukh, LSWG, 17/05/20186Reusing the flat optics hyper-cycle built up in 2017, in particular the 2017 ramp possibly updated for ref orbit, COD settings and collimator alignments, but keeping the 150 mrad EoR crossing angle in IR1 and IR5

Truncated pre-squeeze (3 optics, 110 s): 1m  65 cm

1st tele-squeeze (5 optics, 526 s):

65 cm  60 cm  (60/15)-(15/60)

2nd tele-squeeze (4 optics, 342 s):

(60/15)-(15/60) (30/12)-(12/30)

MD set up & readiness (flat optics)

Already prepared but a priori will not be played

MD activities (flat optics)

MD1 (2 long shifts) 1rst shift (probe, X-angle off below b*=65 cm)OP mechanics including crossing plane rotation EoROptics measurement, K-mod and correction @ 60/15 cm, coupling and IT-b4 correction. If time permits, second fill with X-angle on all along: 150 mrad (0.55 mm)

EoR



130 m

rad (0.3 mm) @ 60/15 cm

2d shift (

if first shift

successful: with 3E11,

X-angle

ON, and new TCT functions)

1 setup fill for Loss maps EoR (?), EoR after crossing plane rotation (?), and EoS  up to 6 probes/beamCollision (ideally 4 IPs, otherwise only IP1/5 if intensity limit exceeded with too many probes needed for LMs)(iii) Loss maps in collisions  2 probes/beam(iv) Aperture @ 60/15 cm (negative X-angle in IR5 for B1 and CMS IP shift: worst case)  2 probes/beam(v) Off-momentum Loss maps (?)1 validation fill for asynchronous dump test @ 60/15 cm with TCT @ 8 sMD2: activity to be cont’d for intensity ramp up, targeting a few trains for BBLR studies (crossing angle reach, BBLR mitigation with MO, etc.) 17/05/2018S. Fartoukh, LSWG, 17/05/20187

S. Fartoukh, LSWG, 17/05/2018

8Result from last year: (60-15)-(15-60) was reached and correctedOnly B1 was actually measured (with AC-dipole) and corrected: with one un-resolved peak @ 25% for B1H, and <10% for B1V

Courtesy of T. Persson and OMC team

17/05/2018

17/05/2018

S. Fartoukh, LSWG, 17/05/20189Expected difficulties for the flat MD with 3E11 (2d shift)In the EoR (b*=1 m), after the X-plane rotation (HV crossing in IR1/5 with 150 m

rad), the IT aperture is no longer that comfortable

(~ 12-13

s assuming an already good optics), limited in the new crossing planes (H/V for IR1/5)

 The TCT ramp functions (n-sigma) may need to be revisited.

 Functions remains to be defined for the centers during the X-rotation.

In the

EoS

(

b

*=60/15 m, 130 mrad), the IT aperture is 8.8 s, (8.6 s with CMS IP shift) limited in the ||-plane (V/H for IR1/5), while the TCDQ settings are7.1 s for B1 vs. 7.3 s @ 25 cm presently

7.8

s

for

B2 vs. 7.3

s @

25 cm presently

OK for B1, but a (slight) reduction of the TCDQ jaw (within BETS tolerance) might be advisable during the first squeeze step of B2

(or

EoR

?)

Back-up slides

17/05/2018S. Fartoukh, LSWG, 17/05/201810

Beam1

Beam2MKDO-TCT phase [o]Tele-index2: r|| × rX

150

o

3×3

Round Tele-Squeeze

MKD-TCT phase

Beam1

Beam2Horizontal b-function at TCDQ [m]Tele-index2: r|| × rX

515 m

3×3

Round Tele-Squeeze:

b

x

at TCDQ

Beam1

Beam2MKDO-TCT phase [o]Tele-index2: r|| × rX

150

o

5×1

4×1

3

×1

Flat Tele-Squeeze

MKD-TCT phase

Beam1

Beam2Horizontal b-function at TCDQ [m]Tele-index2: r|| × rX

515 m

5×1

4×1

3

×1

Flat Tele-Squeeze:

b

x

at TCDQ