2020c run planand MEXT SuperKEKB Roadmap2020
Y. Suetsugu
KEK

2020/6/22

B2GM 2020 June 2211) 2020c run plan
1) Brief summary of results in 2020a, b until June 202) 2020c run plan and luminosity projection2) MEXT SuperKEKB Roadmap2020
1) Update of Roadmap2020
2) Reasons of the update3) Long-term luminosity projection

2020/6/22

B2GM 2020 June 2221) 2020c run plan
1) Brief summary of results in 2020a, b until June 202) 2020c run plan and luminosity projection2) MEXT SuperKEKB Roadmap2020
1) Update of Roadmap2020
2) Reasons of the update3) Long-term luminosity projection

2020/6/22

B2GM 2020 June 223

Brief summary of results in 2020a, b• Near term luminosity projection (~2020/June)(1) Base (conservative) plan
I [A] ( 𝐼+ 𝐼− )(1576 bunches)~0.8A

Presented in last BPAC

Beam dose [Ah]P x I [Pa A]
BG from storage beam

(1576 bunches)Cal., Assumption■ Result in 2019c●

Lsp x by* [x1031 cm-1s-1] vs
Ib+xIb-[mA2](1576 bunches)(1576 bunches)~1.8 kAh(Result in
2019b)(Result in
2019c)

by* [mm]

Lp [x1034 cm-2s-1](1576 bunches)

2.2E34cm-2s-1
1mm

2020/6/22

Int. L [fb-1]

B-B param. (HER)(1576 bunches)~100 fb-1(1576 bunches)~0.02(Result in
2019b)

B2GM 2020 June 22

4

Brief summary of results in 2020a, b• Results until June 20●

Cal., Assumption■ Result in 2019c, 2020a, b

I [A] ( 𝐼+ 𝐼− )Beam dose [Ah](783, 978 bunches)~1.8 kAh~0.8A(783, 978 bunches)~0.67AP x I [Pa A]
BG from storage beam
(783, 978 bunches)

Lsp x by* [x1031 cm-1s-1] vs
Ib+xIb-[mA2]
2020/6/20-6/21
CW L80% H40%
978 bunches(Result in
2019b)~1.1 kAh(Result in
2019c)

by* [mm]

Lp [x1034 cm-2s-1](783, 978 bunches)

Int. L [fb-1](783, 978 bunches)

2.2E34cm-2s-1

2.4E34cm-2s-1~100 fb-1

B-B param. (HER)
2020/6/20-6/21
CW L80% H40%
978 bunches~0.025~0.02~60 fb-1(Result in
2019b)

1mm 1mm

2020/6/22

B2GM 2020 June 225Brief summary of results in 2020a, b• Results until June 20
by* [mm]

Lp [x1034 cm-2s-1](783, 978 bunches)

2.2E34cm-2s-1

Lsp x by* [x1031 cm-1s-1] vs
Ib+xIb-[mA2]
2020/6/20-6/21
CW L80% H40%
978 bunches

2.4E34cm-2s-1(Result in
2019b)

1mm 1mm• by* was kept at 1 mm
• Physics run with by* = 1 mm was achieved.
• Peak luminosity increased almost as expected.
•

Mainly thanks to the crab waist collision scheme in both LER
and HER.

• Specific luminosity vs bunch-current products was almost as
expected, and higher at high bunch-currents.
••
2020/6/22

Specific luminosity was kept at high value at high bunchcurrents thanks to the crab waist collision scheme.
But still affected from beam-beam effect.
B2GM 2020 June 22

6Brief summary of results in 2020a, b• Results until June 20
Int. L [fb-1](783, 978 bunches)

I [A] ( 𝐼+ 𝐼− )(783, 978 bunches)~0.8A~100 fb-1~0.67A

Beam dose [Ah]~1.8 kAh(783, 978 bunches)~1.1 kAh~60 fb-1• Int. luminosity was less than expected.
•••

More machine-study time than planned, such as HER crab waist
scheme. But it contributed to increase peak luminosity.
More down time than expected due to machine troubles, Belle IIdetector troubles, lots of beam aborts, and so on.

As a result, the efficiency was less than 70% (50~60%).

• Beam current was less than expected.
••
2020/6/22••

Operation with smaller number of bunches, and then difficulty inbeam injection at high bunch currents due to beam-beam effect.
Some hardware (vacuum) problem at high-bunch currents.
Limit of TOP background level was lowered to 1 MHz.

Due to low beam currents and shorter running time, the beam dose
was also less than expected consequently.
B2GM 2020 June 227

Major works during summer shutdown• Hardware• Installation of one vertical-type beam collimator in LER•

D03_V1•

Change the material from Tantalum to Carbon• Replacement of D06_V1 collimator head
• Replacement of flux concentrator (e+) and pulsed bending
magnets in Linac• Software• Preparation of various tuning tools•••

For example, tools to control rotatable sextupole magnets inphase.
Preparation for synchrotron injection
Collision feed-back system• Others• Regular maintenances, only possible in long shutdown.

→Improvement in background, injection efficiency andmachine tunability are expected to some extent.
2020/6/22

B2GM 2020 June 2282020c machine time
• 2020c will start from Oct. 19, after summer shutdown.
•

Linac will start from Sept. 28 prior to that for the tuning (BT, DR)
and PF injection.

• 2020c will stop Dec.18.
• 180 shifts (60 days) in total•••~112 shifts for physics run~64 shifts for machine study and tuning
4 shifts for regular maintenances, and 8 shifts for Linac studies
Draft of 2020c machine time
2020
October
28 1

BT Study

November

11

21

1

11

December
21

1

11

21

Linac, Dr, BT Study (Dump mode)

MR

19

28

11

25

9

18

Owl shiftDay shift
Swing shft
Machine study
Physics run
Linac study
MaintenanceTotal

2020/6/22

56
112
8
4
180

Shifts (includes startup tuning)
Shifts
Shifts
Shifts
ShiftsB2GM 2020 June 2292020c run plan
• Main theme of 2020c is to squeeze by* as planned.
••

Operation with by* = 1 mm was achieved in 2020b.
Goal is by* ~ 0.6 mm.

•••

Similar to 2020b.
We need some time to calm down and think the results of studies.
Basically, owl shifts and weekends are assigned to physics run.

• Machine time will not be dedicated to machine studies, but
the studies will be scheduled appropriately in parallel withphysics run.

Draft of 2020c run plan
2020
October
28 1

BT Study

November

11

21

1

11

December
21

1

11

21

Linac, Dr, BT Study (Dump mode)

MR

19

28

11

b y*=1.0 mm

b y*=0.8 mm

25

9

18

Owl shiftDay shift
Swing shft
Machine study
Physics run
Linac study
MaintenanceTotal

2020/6/22

56
112
8
4
180

Shifts (includes startup tuning)
Shifts
Shifts
Shifts
ShiftsB2GM 2020 June 22b y*=0.7 mm

b y*=0.6 mm

102020c run plan
• Major study items•••

Main item is to squeeze by*. We will try by* of 0.8 mm in this run.
Studies to realize stable operation with these by*, accordingly.
• Injection, background, etc.
Beam-beam and optics studies for future runs
• The Crab waist collision scheme will be kept in 2020c.
Draft of 2020c run plan
2020
October
28 1

BT Study

November

11

21

1

11

December
21

1

11

21

Linac, Dr, BT Study (Dump mode)

MR

19

28

11

b y*=1.0 mm

b y*=0.8 mm

25

18

9

Owl shiftDay shift
Swing shft
Machine study
Physics run
Linac study
Maintenance
Total

56
112
8
4
180

Shifts (includes startup tuning)
Shifts
Shifts
Shifts
ShiftsStart up
- Vacuum scrubbing (40 Ah)- Recovery to 2020b condition- Injection study

2020/6/22

b y*=0.7 mm- Squeezing by* to 0.8 mm, 0.7 mm, 0.6 mm- Injection study/tuning- Background study- Beam-beam / optics study- Other hardware/software studies
B2GM 2020 June 22b y*=0.6 mm- Machin studies ifnecessary- Optics study

11Luminosity projection of 2020c (and 2021a)• On the basis of the results in 2020a and b, luminosity
projection was re-evaluated. [Base plan]••

Int. Luminosity etc. were adjusted to the present values.
Similar specific luminosities and beam-beam parameters.
• Crab-waist collision scheme●

I [A] ( 𝐼+ 𝐼− )(978 bunches)Cal., Assumption ■ Result in 2019c, 2020a, b ● Original plan in 2019a,b

Beam dose [Ah]P x I [Pa A]
BG from storage beam

(978 bunches)(978 bunches)~1.7kAh

Lsp x by* [x1031 cm-1s-1] vs
Ib+xIb-[mA2](978 bunches)(Result in
2019b)~0.74A(Result in
2019c)

by* [mm]

Lp [x1034 cm-2s-1](978 bunches)~4E34cm-2s-1(978 bunches)

B-B param. (HER)(978 bunches)~0.025~110 fb-1(Result in
2019b)

0.6mm
2020/6/22

Int. L [fb-1]

B2GM 2020 June 22

12Luminosity projection of 2020c (and 2021a)• For 2021a, we assumed that it is dedicated to physics run,and that 6.5 ~ 5.5 months’ operation this year (depends on
the budget, as you know.).
●Cal., Assumption ■ Result in 2019c, 2020a, b ● Original plan in 2019a,b

Lp [x1034 cm-2s-1]

Int. L [fb-1](978 bunches, 6.5mo)(978 bunches, 6.5mo)~240 fb-1~6.5E34cm-2s-1

I [A] ( 𝐼+ 𝐼− )by* [mm](978 bunches, 6.5mo)

~0.9A

0.6mm

• In summary,Parameters

Base plan until 2020c
Base plan until 2021a(Depend on operation time)
2020/6/22

Int. L [fb-1]

Lp [E34]

Imax [A] (ave.)by* [mm]

~110

~4

0.74

0.6

240~140

6.5~4.5

0.9~0.75

0.6

B2GM 2020 June 22

13

Summary• 2020b has been operated successfully with by* = 1 mm andadopting crab-waist collision scheme in both LER and HER.
• 2020c will start from Oct. 19, and will stop on Dec. 18.
• 180 shifts (60 days) in total• Machine time will not be dedicated to machine studies, butwill be scheduled appropriately in parallel with physics run.
• Main study item is to squeeze by*, down to ~ 0.6 mm (goal).
• Studies to realize stable operation with these by*, accordingly.
•

Injection, background, etc.

• Important to predict the future operation.

• Luminosity projection of 2020c (and 2021a) is re-evaluatedbased on the results until 2020a and b.
Parameters

Base plan until 2020c
Base plan until 2021a*(Depend on operation time)

Int. L [fb-1]

Lp [E34]

Imax [A] (ave.)by* [mm]

~110

~4

0.74

0.6

240~140

6.5~4.5

0.9~0.75

0.6*Here we assumed 6.5 ~ 5.5 months’ operation this year.
2020/6/22

B2GM 2020 June 22

141) 2020c run plan
1) Brief summary of results in 2020a, b until June 202) 2020c run plan and luminosity projection2) MEXT SuperKEKB Roadmap2020
1) Update of Roadmap2020
2) Reasons of the update3) Long-term luminosity projection

2020/6/22

B2GM 2020 June 2215

SuperKEKB Roadmap2020• Roadmap2020 is a fundamental plan of MEXT on the
promotion of large-scale projects in academic research.
• Revised every three years.

• Now we are making the SuperKEKB Roadmap2020, i.e.,the coming ten years’ operation plan.
• The proposal was already submitted to MEXT in February.
The examination will start from June, and the hearing isplanned in August (if selected).

• In this roadmap, we updated the present operation plan(2019) considering the actual situation and the results
obtained so far.
• It is not so big change as a successive project, but changes
towards more realistic one.

• Here we report key points in the update.
2020/6/22

B2GM 2020 June 2216SuperKEKB Roadmap2020• Present plan
• Proposed in last BPAC, 2019
• Updated based on the results until Phase-2

RF[full]

PXD

2020/6/22

Int. luminosity [ab-1]

Peak luminosity [x1035 cm-2s-1]

Last BPAC

B2GM 2020 June 22• Peak luminosity 8E35 cm-2s-1 in~2026• Integrated luminosity 50 ab-1 in ~2028• by*=0.3 mm in 2021
• PXD exchange in 2021~2022• RF full upgrade (4 stations) in 2024
• Max. beam currents: LER 3.6 A, HER
2.6 A (2500 bunches) in 2026
• Basically, 8 moths’ operation per year.
[Investment in equipment]• Full-scale RF-power upgrade (add 4
stations)• Beam collimator upgrade• Linac upgrade• Belle II upgrade

17SuperKEKB Roadmap2020

Int. luminosity [ab-1]

Peak luminosity [x1035 cm-2s-1]• Update plan (Roadmap 2020)

RF[partial]

IR (QCS*)

PXD(Tuning)*QCS:
Superconducting final focusing quadrupole magnet

2020/6/22

B2GM 2020 June 22• Peak luminosity ~6E35 cm-2s-1 in ~2028• Integrated luminosity 50 ab-1 in ~2030(40 ab-1 in ~2029)• PXD exchange in 2021~2022• IR (QCS and its beam pipes etc.)
upgrade in 2026
• Partial RF-power upgrade (2 stations)in 2026• by*=0.3 mm in 2026 after IR upgrade,and ~0.5 mm before that• Max. beam currents: LER 2.8 A, HER
2.0 A (1761 bunches) in 2027
• Basically, 8 moths’ operation per year.
[Investment in equipment]• QCS and its beam pipes etc.
• Partial RF-power upgrade (2 stations)• Beam collimator upgrade• Linac upgrade• Belle II upgrade

18

Main reasons to update the operation plan
• Main reasons:(1) Increase in the running cost (utility cost )(2) Challenges found in the initial operations (～2019c) ：(a) Strong beam-beam effects at high bunch-current region(b) Narrow physical aperture in QCS(c) High background in Belle II(3) Small dynamic aperture at high bunch-current region at
small by* (~0.3 mm), which has been recognized from thedesign phase.

2020/6/22

B2GM 2020 June 2219

Main reasons to update the operation plan
• Reason-1(1) Increase in the running cost (utility cost )• If we want to run with the max. beam currents in the original
design (LER 3.6A, HER 2.6A), approximately 1.6 times of theelectric power (i.e., running cost) is required compared to thatat present (1～0.5 A) .
• If the operation budget does NOT drastically increase, and theelectricity unit cost remains at similar level, the operation period
per year will be strictly limited.
• As a result, it takes long time to achieve the goal integratedluminosity, and the total running cost will further increase
consequently.
→ More effective (ecological), that is, more higher collisionperformance with smaller beam currents is required to achieve
the goal in a reasonable period
2020/6/22

B2GM 2020 June 2220

Main reasons to update the operation plan
• Reason-2(2) Challenges found in the initial operations (～2019c) ：(a) Strong beam-beam effects at high bunch-current region• In the low bunch-current
region(ib+ib- < 0.1 mA2), thespecific luminosity increased inproportion to 1/by* until by*=1mm.
• This clearly indicates that thenano-beam scheme works well
as expected in SuperKEKB.
• A great achievement inSuperKEKB

2020/6/22

Dependence of specific luminosity on 1/by* at
low-bunch current region

B2GM 2020 June 2221

Main reasons to update the operation plan
• Reason-2(2) Challenges found in the initial operations (～2019c) ：(a) Strong beam-beam effects at high bunch-current region• On the other hand, in high bunch-current region (ib+ib->0.2～0.3 mA2),
owing to the vertical-beam size blowup due to the beam-beam effect,
the specific luminosity is lower than expected, and the beam-beam
parameter is also lower.
• Main reason is said to be the chromatic x-y coupling at IP (Interaction
Specific luminosity vs. bunch-current products
Point), but not yet confirmed.
• Crab waist collision
scheme and utilizing
skew sextupole magnets
are promising solutions atpresent, but theeffectiveness is notconfirmed yet until the
final goal of by*= 0.3 mm.
2020/6/22

B2GM 2020 June 2222Main reasons to update the operation plan
• Reason-2(2) Challenges found in the initial operations (～2019c) ：(a) Strong beam-beam effects at high bunch-current region• One promising method to mitigate the effect will be the modification of
QCS to avoid the interference between quadrupole magnetic field andthe Belle II solenoid for LER.
QCS magnets• Further study is on going.
Solenoid field (Bz) and integrated Bz in QCS

Cross section of QCS

2020/6/22

B2GM 2020 June 2223

Main reasons to update the operation plan
• Reason-3(2) Challenges found in the initial operations (～2019c) ：(b) Narrow physical aperture in the QCS Beam size in QCS• Quenches of QCS caused by the hittingof unstable beams have been observed.
• In the worst case, it may result in thedamage of coils.
• At present, beam collimators is effectively
preventing them by closing thecollimators to the narrower physicalapertures than the beam pipe in QCS.
• However, if we want to squeeze by* to lessthan 0.5 mm, the by at QCS become
further larger, and it will be difficult toprotect the QCS by using collimators.
• The narrower the beam collimators,
the shorter the beam lifetime, and thehigher the risk of damage ofcollimators due to the hitting of beam.
2020/6/22

B2GM 2020 June 2224

Main reasons to update the operation plan
• Reason-4(2) Challenges found in the initial operations (～2019c) ：(c) High background in Belle II• At present, the background of Belle II is larger than expected.
• Main cause is the hitting of storage and/or injection beam halo to thebeam pipe in QCS.
• The background also depends
on the vacuum pressure in thering and the quality of injection
beams.
• The background will become
severer as squeezing by* further.
• The by at QCS become large
and the beam hallow will beeasier to hit the beam pipe.

2020/6/22

B2GM 2020 June 22

Source points of background (reconstructed from
CDC track data) [H. Nakayama, SuperKEKB WS.]

25

Main reasons to update the operation plan
• Reason-5(3) Narrow dynamic aperture at high-bunch current at small by*• It was reported that the LER Touschek life time will be approximately
200 s due to the narrow dynamic aperture at by* = 0.3 mm and thebeam-beam parameters ~0.09. (Designed lifetime is approximately
600 s)• This fact has been pointed out
around 2014, and thesimulation studies has been
continued since then.
• The problem, however, has notbeen solved so far. Somemeasures should beconsidered to reduce by* further.

2020/6/22

B2GM 2020 June 22[Y. Ohnishi, 18th KEKB Review, 2014]26

Main reasons to update the operation plan
• Present situation• If the design beam currents of LER 3.6 A and HER 2.6 A are realized(2185 bunches) after full-scale RF upgrade, but the by* is limited to 0.5mm, the peak luminosity will be ~4E35 cm-2 s-1 at most.
• As described before, weneed more utility cost tooperate with these beam
currents. Even if we canoperate for 7 months per
RF[full]
year, after making various
PXD
efforts, it will be 2032~2033
to achieve the integrated
luminosity of 50 ab-1 (~40
ab-1 at ~2031).

Update of present operation plan
2020/6/22

B2GM 2020 June 2227

Key points of update(1) Aim an ecological operation suppressing running cost, i.e., beam
currents, as much as possible.
• Put the priority on the integrated luminosity, rather than the peakluminosity.
• Realize an integrated luminosity of ~50 ab-1 at the reasonable time
not so different from the previous plan.

(2) Modify IR, especially upgrade QCS and it’s beam pipes, in orderto make it possible squeeze by* to 0.3 mm, to mitigate the beambeam effect at high bunch-current region, to protect QCS, and to
reduce the background, then to increase the collision performance,
the stability and the data-taking efficiency.

2020/6/22

B2GM 2020 June 2228

Key points of update• Upgrade of QCS and its beam pipe
(1) Relocation of magnet positions• Mitigate the beam-beam effect by avoiding the interference between
quadrupole magnetic field and the Belle II solenoid.
• Further study is on going.

• The narrow dynamic aperture issue at small by* might be solved byField profiles [Ohuchi]
modifying QCS.

(2) Enlargement of apertures of QCS
beam pipes• Make it possible to squeeze by*down to 0.3 mm and to operatesafely at high beam currents.
• Effective to mitigate thebackground.
• Installation of radiating shield(heavy metals) inside the QCS
cryostat will be possible at thesame time.

2020/6/22

B2GM 2020 June 22

Beam pipes in QCS [Ohuchi]

29Key points of update(1) Aim an ecological operation suppressing running cost, i.e., beam
currents, as much as possible.
• Put the priority on the integrated luminosity, rather than the peakluminosity.
• Realize an integrated luminosity of ~50 ab-1 at the reasonable time
not so different from the previous plan.

(2) Modify IR, especially upgrade QCS and it’s beam pipes, in orderto make it possible squeeze by* to 0.3 mm, to mitigate the beambeam effect at high bunch-current region, to protect QCS, and to
reduce the background, then to increase the collision performance,
the stability and the data-taking efficiency.
(3) Keep option to upgrade the RF power at the minimum level.
• Store the beam currents of LER 2.8 A and HER 2.0 A stably.
•

Even if not upgraded, the beam currents of LER 2.5 A and HER1.8A will
be possible.

(4) Investment of equipment for the upgrade of Linac, Belle II andbeam collimators of MR are essential the same as before for stable
and high-efficiency operation.
2020/6/22

B2GM 2020 June 2230

Key points of update• Major upgrades (Investment of equipment)• Belle II
•
•
•
•
•
•

Preparation of SVD spare.
Replacement of CDC FEE and readout circuits
Replacement of PID (MCP-PMT) in Barrel
Replacement of PID (HAPD) in ARICH
Replacement of a part of ECL
Modification of IP beam pipe

•
•
•
•

Development of collimators and high-precision supports
Installation of ECS (Energy Compression System) for e- line
Addition of pulsed magnets
Replacement of thousand capacitors with PCB inside• Linac• MR• Modification of IR, including QCS, its cryostat, beam pipes inside,
and RVC• Upgrade of RF power stations and control system• Development of robust beam collimators• Reinforcement of radiation shield around IR and collimators

2020/6/22

B2GM 2020 June 2231

Rough schedule of upgrade

2020/6/22

B2GM 2020 June 2232

Long-term luminosity projection• Update of luminosity projection• After these upgrades in 2026, the stable operation at highbeam currents (LER 2.8A and HER 2.0A) with by*of 0.3 mm will
be possible. If the beam-beam parameters of 0.07~0.08 areachieved, the peak luminosity will be ~6E35 cm-2 s-1.
• If 8 months’ operation per year is realized, again after making
various efforts, the integrated luminosity of 50 ab-1 will beachieved in ~2030 (40 ab-1 in ～2029).

RF[partial]

IR (QCS)
PXD

0.3 mm(Tuning)(Tuning)
2020/6/22
2020/6/16

B2GM 2020 June 22

Belle II EB

33

Long-term luminosity projection• Note• If we have NO upgrade of IR (QCS and beam pipes) and RF
power (Max. LER 2.5 A /HER 1.8 A, by*= 0.5 mm), assuming
8 months’ operation per year, the integrated luminosity of 50
ab-1 will be achieved in 2032~2033 (40 ab-1 in 2031).
• These upgrades promote the achievement of the goal, andalso expand option in the operation, and as a result, reduce
the risk.
No IR and RF-power upgrade

IR upgrade in 2026

RF

[partial]

IR (QCS)PXD

PXD(Tuning)

2020/6/22

B2GM 2020 June 22

Belle II EB

34

Summary• MEXT SuperKEKB Roadmap 2020
• Perform the collision experiments with a several ten-times
higher luminosity than that in the preceding KEKB project byusing the nano-beam collision scheme.
• Aim an integrated luminosity of 50 ab-1 in coming 10 years.
• Update the operation plan:•••

Aim ecological operation with high efficiency, and put the priority
on the integrated luminosity, rather than the peak luminosity.
Modify IR, especially upgrade QCS and its beam pipes, tosqueeze by* to 0.3 mm as designed, and then increase thecollision performance.
Investment of equipment, such as Linac upgrade, Belle II
upgrade, beam collimator upgrade, are planed as before, which
are essential for stable and efficient operation at high beam
current.

• The plan is within the framework of MEXT Roadmap, but it seems
more realistic considering the present situation.
2020/6/22
2020/6/16

B2GM 2020 June 22

Belle II EB

35

Thank you for your attention.

2020/6/22

B2GM 2020 June 2236

Long-term luminosity projection• Note-2• It is clear that ahead of upgrade schedule of QCS/RF greatly
speed up the luminosity accumulation.

IR upgrade in 2026

IR upgrade in 2025

RFRF

[partial][partial]

IR (QCS)IR (QCS)PXD

PXD(Tuning)(Tuning)

2020/6/16

2020/6/22
2020/6/16

B2GM 2020 June 22

Belle II EB

37

2020c run plan
• Major study items• Optics••

Squeezing by* down to 0.6 mm
Precise measurement and correction of optics parameters••

Two bunch injection
Synchrotron injection•

Beam collimator tuning•

Investigation of the cause•

Bunch spacing and number of bunches•

Effect of IP chromatic coupling on beam-beam blowup• Measurement of optics parameters at IP• Utilization of rotatable sextupole magnets (LER) and skew
sextupole magnets (HER)High bunch-current operation to check beam-beam effectCrab waist scheme• Injections• Beam background• Beam aborts• Fill patterns• Beam-beam••
2020/6/22

B2GM 2020 June 2238

Operation plan and luminosity projection• Near term operation plan (~2021/March=FY2020)●(1) Case N1: 6.5 months operation

Cal., Assumption■ Result in 2019cPresented in last BPACI [A] ( 𝐼+ 𝐼− )Beam dose [Ah]~1.1A

~3.7 kAh

P x I [Pa A]
BG from storage beam

Lsp x by* [x1031 cm-1s-1] vs
Ib+xIb-[mA2](Result in
2019b)(Result in
2019c)

by* [mm]

Lp [x1034 cm-2s-1]~9.5E34cm-2s-1~500 fb-1

B-B param. (HER)~0.034(Result in
2019b)

0.5 mm2020/6/22

Int. L [fb-1]

B2GM 2020 June 2239

Updated luminosity projection (parameters)• Long term operation plan-1( 𝐼+ 𝐼− )2020/6/22

B2GM 2020 June 2240

Updated luminosity projection (parameters)• Long term operation plan-2

2020/6/22

B2GM 2020 June 2241SuperKEKB Roadmap2020• Original plan (until 2018)
•
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Peak luminosity 8E35 cm-2s-1 in ~2025
Integrated luminosity 50 ab-1 in ~2027
PXD exchange in 2020~2021
RF full upgrade (4 stations) in ~2023
Max. beam currents: LER 3.6 A, HER
2.6 A (2500 bunches)• Basically, 8 moths’ MR operation per
year.
RF(full)

Investment in equipment• Beam collimator upgrade• Linac upgrade• Belle II upgrade• Full-scale RF-power upgrade (4stations)

PXD

http://www-superkekb.kek.jp/img/ProjectedLuminosity_v20190128.png

2020/6/22

B2GM 2020 June 2242