Progress ofD05V1 Collimator Installation
2022/12/14
Akio Moritap.01

What’s NLC●NLC(Non Linear Collimator) is constructed by...
– Quadratic(Non Linear) Kick by Skew Sextupole: Δθ y ∝ K2 (y2-x2)– Quasi-π/2 Telescope: Ltele. ≡ TM34(sext.→coll.)＝＞ Δycoll. ∝ Ltele. K2 (y2-x2)– D05V1 Collimator with variable vertical aperture: A coll.
●Collimator kick factor correlates with A coll.-1 & βycoll..

– -I’ cell for Skew Sextupole pair to hide quadratic kick from global beam dynamics

In minimum design, TM 34(sext.→coll.) is constant of device geometry due to -I’ cell matching.
●TM34(sext.→coll.) ~ (βysext. βycoll.)1/2●●

Effective Normalized Vertical Aperture
at Skew Sextupole: N eff ≡ Asext. / σysext.
coll .
●●N 2eff ∝A coll .
A coll . βy1sext . ∼ 3
L tele . ε y K 2 β yK2
L tele . ε y1sext .
σsext.
≡ √ε y β y , |x|≪|y|y

Merit compared with usual collimator– Lower kick factor than usual collimator is available by choosing suitable skew sextupole strength & device

geometry.

p.02

NLC Installation Side Effects●

Lose a part of damping wiggler units (10/56)– Longer damping time on default wiggler setting●●

Damping time COULD be recoverd by wiggler strength,
however, more heat load for wiggler vacuum pipes &heavier wiggler magnet PS load are expected.

Require additonal radition sheild for operation– Considering & Preparing additonal sheilds:

Pb beam pipe cover●Concreate sheild to cover air duct●p.03

Considering Additonal Radiation Sheild

Pb Sheild around Vacuum Pipefrom 122th B-Factory Project Promotion Committee p.13

Concreate sheild to cover air duct spacep.04

NLC Lattice Design Works●Original lattice is proposed by Oide-san.

●Revise device layout for reusing vacuum pipes.

●Rearrange steering magnet position for vacuum componets.

●●Change D05V1 collimator install position to downstream side of center
QUAD (QN3OP) of -I’ cell for avoiding interference to HER beamline
during collimator maintenance works.
Finalize major componet layout for device installtion works.
– Critical collimator performance regression due to D05V1 layout minor changes

is not observed in BG simulation results.

– Detail BG simulation to optimize optical parameters is ongoing by Andrii.

p.05

Checked Optics Issues
Optimized Lifetime●Optimized Touscheck lifetime(DA) regression– Almost same lifetime is obtained at NLC off case.
– 10% lifetime regression by NLC sextupole.

●Local Bump around D05V1 collimator for BG study etc...

@ β*y = 1mm (sec)

CW

80%

60%

κ

3%

2%

3%2%

before

1405

1349

2092

1549

NLC(off)

1430

1336

2104

1837

NLC(on)

1274

1201

1769

1647– A few millimeter bump height WOULD be available.

●BG dependence with D05V1 minor layout variation.
– Typical checked D05V1 layouts:

D05V1 upstream of QN3OP●
D05V1 downstream of QN3OP (*)●
D05V1 between splited QN3OP●– Critical regression is detected in Andrii’s BG simulation, therefore, we choose (*) layout suitablefor collimator maintenance works.

p.06

Device Layout
HER(e-) →Wiggler will be removed← LER(e+)

Split Q Family
Before Installation

Oide’s Propostal

Relayout Region

Finalized Layout-I’ cellp.07

Optical Function
Before Installation

Oide’s Proposal

Finalized Layout

LER(e+) →p.08

Completed Construction Works●Open & Remove concrete radiation shieldblocks for construction works.
– They WOULD be reinstalled in late August 2023.

p.09

Ongoing Construction Works●Remove 10 wiggler unit & vacuum pipes.
– 50 dipole magnets (~ 6.5 ton)
– 10 vacuum pipes– Wiggler magnet power cables (~ 3 ton)

Almost finished at this moment
p.10

Wiggler Removal Works

Before removal works

Remove vacuum pipes

After removal works

Removed wigglers

2022/12/08

Removed cables

Detach upper pole for access

Restore upper pole for transfer

p.11

Upcoming Construction Schedule
Installation works are planned to complete until October 2023.

Year2022

Month12Wiggler

RemovalQuadrupole

2023
01

02

03

04

06

07

08

09

Cabling
Cabling

Relocation

Magnet Material & Parts Preparation

Skew Sextupole

05

Magnet mount Fabrication

New Magnet PS

Yoke Fabrication

Magnet Assembling

Field
Installation
Measurement

Adjustment

Fabrication

PS Control System

Development & Deploy

Production & Modification

Vacuum Pipe

Installation

Evacuation

TiN coating & Baking at LaboratoryRelocate Collimator
Radiation Shield
Old Cable Removal

D05V1 installation

D03V1 removal

Pb Sheild

Materal Preparation

Concreate Shield
Wiggler

Fabrication & Installation
Reinstallation

Additional Shield
Installation

Quad
p.12

Backup(Optics Isssue)

p.13

“Local bump @ D05V1, dynamic aperture” p.4, H.Koiso
http://kds.kek.jp/event/43435/

p.14

“Local bump @ D05V1, dynamic aperture” p.2, H.Koiso
http://kds.kek.jp/event/43435/

p.15

“Local bump @ D05V1, dynamic aperture” p.3, H.Koiso
http://kds.kek.jp/event/43435/p.16

Oide’s original

Reimplement on current lattice

D05V1 upstream of QN3OP

Remove drift between D05V1 & QN3OP

Adjust IP-D05V1 vertical phase to π

“LER optics for nonlinear collimator” p.5, H.Koiso
http://kds.kek.jp/event/44526/

D05V1 downstream of QN3OP (*)

D05V1 between splited QN3OP

p.17