Beam Background and BEAST
H. Nakayama(KEK)on behalf ofBelle2 Beam background group
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

1

Goals of Beam Background Group• Overall goals: Estimate, measure, mitigate, andprotect against beam backgrounds• Background sources
–
–
–
–
–
–

•
•

4-fermion final state QED process (Lum.)
Touschek effect (Beam size and energy)
Beam-gas interactions (current, pressure)
Synchrotron radiation
Radiative Bhabha scattering (Lum.)
Injection BG

Can result in instantaneous damage, long term
damage, or excess occupancy in Belle II
Want to measure all backgrounds, validate MC
primarily during phase 2 (BEAST). Use MC to
extrapolate to phase 3.

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)2

Beam BG Group• LEADER, BEAST: S. Vahsen (Hawaii)• BEAST KEK liaison, BG simulation: H. Nakayama (KEK)• Institutes:– KEK, Hawaii, Bonn, Trieste, MPI, Heidelberg, DESY, Wayne, NTU, IFCA,
LAL, IPHC, etc..

• Significant support from accelerator colleagues– Beam loss simulation– BEAST machine study operation

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

3

Background simulation(for design luminosity)

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

4

Background simulation updates• In the last ARC, 8th campaign result was reported.
• 9th campaign– RBB_LER rate increased• we found the wrong LER lattice (solenoid off) was used before– B=1.51.2T was investigated• Only 20~30% decrease on TOP PMT rate (we need factor 3), 35% increaseof PXD occupancy, challenge for tracking and accelerator optics tuning• 10th/11th campaign– Only minor updates in shield geometry, loss rates– BG level dependence on collimator width are investigatedHiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)5

Ver. 2015.1.30(11th campaign)

BG loss distribution

Loss wattage= loss rate
* energy of loss particle

LER
(e+)

HER
(e-)

1GeV ,1GHz= 0.16W
LER (4GeV e+)HER (7GeV e-)Rad. Bhabha

0.74 W (eff. 1.2GHz)

0.59W (eff. 0.52GHz)

Touschek

0.05 W (0.08GHz)

0.02 W (0.02 GHz)

Coulomb

0.10 W 20th
(0.16GHz)
0.001W (0.001GHz)
ARC (Feb. 23-25, 2015)

Hiroyuki Nakayama (KEK)6

Tungsten shields in QCS cryostat
tungsten (10mm t)tungsten(20~70mm t)tungsten (25mm t)
QC2RE

e-

QC1RE
QC1RP

IP

1m

QC2RP

tungsten(~30mm t)NEW!
tungsten (20mm t)e+tungsten (10mm t)e+e-

Major beam loss position
by Touschek or Beam-gas

Hiroyuki Nakayama (KEK)-1m
Thick tungsten shields can significantly stopbackground showers originated from |s|>65cm.
20th ARC (Feb. 23-25, 2015)

IP
7

Shields outside QCS 17°
Iron
VXD docks

Thick tungsten layers inside cryostat
Heavy metal shields to protect VXDfrom showers generated in cryostat

ECL
Iron

CDC

Neutron shield inside ARICH structure
Neutron shield for CDC elec. board.
(Polyethylene)

VXD docks

ECL shield, included for
ECL/ARICH simulation(Lead + Polyethylene)

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

RVC structure in front of QCS stops
showers from RBB HER loss at z=60cm
8(6cm-thick SUS steel assumed)

11th campaign results

20th B2GM background parallel session:
http://kds.kek.jp/sessionDisplay.py?sessionId=203&confId=17439#20150203

CDC: OK

PXD, SVD: OK
Two photon occupancy (%)
layer 1: occ= 0.83 +- 0.05 (max= 0.90)
layer 3: clusters=176.14,
per sensor=12.58 +- 3.14 (max=18.64)
TOP: BAD (need factor x3)

Hiroyuki Nakayama (KEK)

ARICH:OK

ECL:OK

RBB_LER increasedsince
20th ARC (Feb. 23-25,
2015)the last BPAC

9

Summary for 11th campaignlisting SF<5 only
SF=Safety Factor
11th campaign result

limit

SF

PXD occupancy

2photon:0.9% , SR:~0.2% (10th)

< 3%

3

CDC wire hit rate

165kHz<200kHz

1.3

CDC Elec.Borad n-flux*

1.1

<1

1.5

CDC Elec.Board dose

72Gy/yr<100 Gy/yr

1.3

TOP PMT rate

3MHz/PMT<1 MHz/PMT

0.3

TOP PCB n-flux*

0.15

<0.5

3

ARICH HAPD n-flux*

0.3

<1

3

ECL crystal dose

3.1 Gy/yr<10 Gy/yr

3

ECL diode n-flux*

0.24

<1

4

ECL pile-up noise

3.8/1MeV

0.8/0.2MeV at
Belle-I?

KLMs studies are not included
Hiroyuki Nakayama (KEK)

With “combined”
shield at inner ECL
20th ARC (Feb. 23-25, 2015)*neutron flux in unit of1011 neutrons/cm2/yr,
NIEL-damage weighted
10T. Ishibashi (KEK)SuperKEKB Collimators Locationfor Beam-gas

for Beam-gas

D01

D02

D12

D03

~20 Horizontal collimators and 2
D04
Vertical collimators
Each collimator can be asymmetric Need to control ~50 parameters!
D05

D11

D10

D09

Hiroyuki Nakayama (KEK)

D08

D07

D06

Phase1: new collimators are only at LER D06 H1,H2

11

LER Touschek
loss [MHz]Touschek life [s]Loss rate vs. LER collimator width

Designwidth

Narrower width is notallowed because TMC beam
instability gets too large

Log scale!!

Designwidth

100000LER Coulomb
loss [MHz]Coulomb life [s]51015LER Horizontal collimator width[mm]Varying only 1 out of ~10
2500
horizontal collimators~10 horizontal collimators- for Touschek- typical width: ~15mm
1 vertical collimator- for Beam-gas Coulomb- typical width: ~2.5 mm- need careful control(mechanical precision: 50um)

2000

10000

1500

1000

1000

100

500

10

Allowed width:
only ~200 um

0
2.4

2.5

2.6

2.7

1
2.8

2.9

3

LER Vertical collimator width[mm]Add shield at RBB hot-spot?
Origin of gammas contributing TOP hits

r14994

Tara (TOP simulation)and Martin (VXD
mechanics) are trying tofind a space (verycrowded actually) for
additional shielding tocover hot spot.
Also, simulationgeometry needs more
realistic implementation(flanges, bellows,etc.).

TaflangeCu
BPM
flangeBellows

Adding shield around BPM/Bellows between QCS and IP
beam pipe is effective to mitigate TOP BG. Space available?

BG simulation summary• After installing many tungsten shields and careful collimatortuning, simulation shows BG levels are acceptable() for 10
year-operation, except for TOP PMT lifetime• For further mitigation, additional shield around BPM/bellows
are being investigated, but the area is very crowded..
• Safety factor is not so big. Simulation/measurement
crosscheck during BEAST period is very important– For example, tip-scattering on collimator head (to be simulated)• Further investigation on possible missing contributions– Plan to also include “elastic” Bhabha scattering, spent e+e- from 2photon process

BEAST

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)15

SuperKEKB: Two Commissioning Phases

BEAST Phase 1: Jan 2016
• Vacuum scrubbing of beam pipe.
• No collisions. Belle will not roll-in.
• Variety of subsystems on fiberglass
support structure• No Belle DAQ, only BEAST DAQ

Hiroyuki Nakayama (KEK)

BEAST Phase 2: May (?) 2017
• Belle rolled in.
• VXD BEAST Assembly••

Partial VXD ladders
Other BEAST sensors• BEAST detectors in dock space andaround QCS• BEAST DAQ & Belle DAQ

20th ARC (Feb. 23-25, 2015)16

Phase 1 Design
PIN Diodes

64 channels: 8 z-positions X 4 phi positions X 2 diodes(shielded+unshielded)
CsI

TPC
BGO

MiniBEAST integration test ongoing in Hawaii. Disassemble and ship to KEK in August.

Installation Plan, Phase 1
3.

1.

Install IP bridge: Completed

Install BEAST Phase 1 at IP: Sep & Oct 2015 [t.b.d.]

4.

2.

IP1 chamber for Phase 1.
Repair & Install IP chamber: ~April & May 2015
Add IP shield wall w/ crane Oct-Nov 2015 [tbd]Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)18

BEAST Phase 1 Activities• Phase1 Priority: Vacuum scrubbing by machine group• BEAST critical activities– Measure SR/particle dose (w/ PIN diodes) to ensure it is “safe” to rollin Belle and VXD Beast Setup– Test beam abort system using VXD diamond sensors– Establish communication between Beast DAQ and collimator control• BEAST “desired” activities– First attempt to compare MC and Beast sensor measurement– Touschek/beam-gas machine study (need emittance control bump)– Injection damping time measurement (although no LER damping ring)

Would like to request <=1 week for this at end of phase 1.
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

19

BEAST Phase2 study• Phase2 is most similar to phase3, but still different
1. “Detuned” optics with smaller IR beta functions (less SR, Toucheck, Beam-gas)
2. Worse vacuum level (more Beam-gas)
3. Smaller luminosity (less RBB/2-photon)
4. VXD ladders at phi ≠ 0 is missing in phase2• We need some extrapolation– For 1, simulation/measurement comparison with detuned optics tells us how
much we can believe simulation with final optics• Collimator secondary shower effect can be measured at phase2.
– For 2. and 3. extrapolation is rather straightforward.
– For 4, beast sensor measurements at phi≠0 is important.

• Separate measurement of each BG sources is important– Vary beam size , vacuum level , luminosity to disentangle Touschek, BeamGas,
RBB and 2photon (same approach with 2010 BG study)– Validate simulation results with measurement
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)20

BEAST Phase2 study• Need all sub-detectors DAQ running (at random trigger)– global Belle II DAQ (partial VXD, CDC, TOP, ARICH,BKLM,EKLM, TRG)
– Extrapolate measured each sub-detector BG level to phase3– Sub-detector DQM records are useful for analysis• Other commissioning items during phase2 period– Slow control (EPICS) communication, timing signals connection btw
SuperKEKB-Belle2, beam abort/injection interlock– VXD CO2 cooling, injection noise damping-time measurement, PXD
ROI finding etc…
– Collimator optimization study• Simulation/measurement comparison with various collimator settings• Develop strategy how to reach optimal collimator setting

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)21

Phase 2 Detectors• VXD BEAST assembly– SVD, PXD ladders at
phi=0– Dedicated backgroundand environment
sensors (see next page)• Scintillators and PIN
diodes around QCS• Neutron detector indock space
Tremendous progress on BEAST VXD assembly mechanical design and plan
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)22

Phase-2 sensors in VXD volume

Feb. 4, 2015

sensorcontact
personnumberlocationDAQ

PXD + SVD

C. Marinas
K. Nakamura

2 PXD ladders
4 SVD ladders

decided+X

Belle II DAQ

diamondw/ PIN diode(beam BG, abort)

L. Vitale

4 diamonds
64 PIN diodes

diamond:decidedBelle II
monitor DB(EPICS)

PIN diode location:around diamond andbeam pipe

FE-I4 pixels(Synchrotron rad. andtrack multiplicity)

C. Marinas

3 armsdecided(90, 180, 270)?

arm design
has to be fixed

CLAWS(beam BG)

F. Simon2 ladders

decided(135 and 225)?

Scintillator
PIN diode(beam BG)

H. Nakayama
K. Nakamura~60 (scintillator)? (PIN diode)not decided?

Basically put themaround QCS

BGO(Bhabha events)

J. Liau8(if space allows)under
discussion

BEAST DAQ

Acceptance is overlappedwith PXD cooling block.

temperature (NTC),
humidity (DMT242B)(crosscheck for FOS)

L. Vitale

not decided

not decided

FOS + L-shape(temp. and humidity)

I. VilaD. Moya

?

?

PLUME
(beam BG)

I. Ripp-Baudot

note

Belle II
monitor DB(EPICS)See backup slides for more on these systems.

Hiroyuki Nakayama (KEK)

1 laddernot decided
20th ARC (Feb. 23-25, 2015)?

sensor on outer cover?

EPICS DB
BEAST DAQ?

baseline: PLUME-2
23(hopefully PLUME-3)

What is the end of phase 2?
• Accelerator reaches L ~ 1034 cm-2 s-1• VXD group agrees BG levels are acceptable, forsafe installation of their detector – criteria tobe defined in note
• All required VXD related protection systems
and services have been tested and arefunctional (beam abort, interlock, VXD
cooling, slow control, collimator strategy)
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

24
24

BEAST Conclusion & Outlook•••

Beam Background group to perform arich set of background measurements,
both with BEAST detectors and Belle II
BEAST detector construction more orless on (tight) schedule
Next Major Milestones, phase 1– MiniBEAST at U. Hawaii: Jan 2015
– Install BEAST at IP: approx. Aug – Oct 2015
– Operate with first beams: mid Jan 2016•

Next Challenges, phase 2– Decide on PLUME and BGO inclusion inphase 2– Finalize VXD space mechanics, cablerouting through dock space, Develop
phase 2 installation plan w/ schedule– Complete document on measurement plan•

BEAST team surveying IP area

Critical Follow-up Issues– Agree on exact phase 1 install dates– Need to decide on BGO, PLUME inclusion– For BG/collimator studies, werequest ~1 week in phase 1, ~2
weeks in phase 2
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)25

backup

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)26

Phase II: Dock SpaceTPC fast neutron detector

He-3 thermal neutron detectors

Neutron detectors in dock space will provide complimentary information. Neutrons hard to simulate.
Hiroyuki Nakayama (KEK)
20th ARC (Feb. 23-25, 2015)
HeroicCAD
effortbyAlexandre
Beaulieu(Victoria)
1/20/2015
Sven Vahsen,
Strasbourgconfirmed
Workshop detectors fit into VXD docks.

2727Document for the BEAST detailed plan
• C. Marinas prepared
VXD plans for phase 2
in detail• We plan to expand this
into Belle2Note, tocover all beam
background plans– i.e. follow-up to
outdated BEAST TDR
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)28
28

Goal of Commissioning Phase 2
Many group working with different goals during phase 2. Beambackground measurements are just a small part of the overall program• Beam commissioning to start collision (machine group: KCG)
– Forward luminosity monitors(ZDLM) for knob tuning• BG measurements and mitigation (KEK Belle group: BCG)
– BG studies of each component to check consistency with simulation– Studies of relation between VXD hits and monitor hits
– Beam collimators control study– Neutron measurement (fast and slow)• Belle II commissioning with partial VXD sensors (Belle II shift)– Full Belle II DAQ– Slow control (also communication with machine)– PXD RoI finding with CDC+SVD tracking data
– Detector noise check– And investigation and confirmation to install the full VXD• Optimization of interlock system– Slow info. Some alarms or abort by environmental or rad. Monitors,
beam injection interlock20th ARC (Feb. 23-25, 2015)
Hiroyuki Nakayama (KEK)29– First info.: beam abort by hard wired signals

Adapted from Tanaka San/ Nakamura San

Goal of Commissioning Phase 2 (part II)• Beam injection BG study (VXD group)– BG damping time measurement for Trigger veto gate
• Requiring storing veto gate width to condition database• With moderate update timing• First try of CO2 cooling system for VXD sensors (VXD group)– Checking water vapor level by sucking air– cold and warm dry volume• Detailed characterization of beam backgrounds (BEAST
group)– Target luminosity at phase-2 is L ~ 1034 cm-2 s-1 , and BG structure
is not exactly same as phase-3. We need somehow extrapolation
to expect phase-3 beam BG.
• how to extrapolate it?
– We have a lot of monitor sensors, diamond sensors, 64 PIN diodes, FE-I4, CLOWS.
– Effect from each BG component has to be measured separately– This extrapolation can be done only after the BG is well controlled by collimator
studies.
30–
Deferent
BG
components
havedifferent
dependenceforcollimatorsetting.
Hiroyuki Nakayama (KEK)
20th ARC (Feb. 23-25, 2015)30

BG simulation tasks•

BBBREM+BHWIDE combined sample study -- Hiro, Chris, Funakoshi– Now only using BBBREM, which always emits 1photon– Include elastic scattering contribution with BHWIDE

•
•
•
•
•
•
•

Two-photon spent e+/e- tracking by SAD, for outer detectors -- Hiro, Marin,
Funakoshi
RBB gamma -- HiroSR simulation with Beast optics (both phase1/2) -- Yuri
Beam-gas for Beast phase2 with detuned optics --Ohnishi
Collimator dependence with fine steps (50um/100um/200um) -- Ohnishi
EKLM polyethylene shield study – resume KLM group activity!
Collimator secondary shower study -- Uvic student?

• SAD install in KEKCC clusters? – software group experts
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)31

Summary for 8th campaign* Not including halo ,mis-alignment effect

SF=Safety Factor

8th campaign result

limit

SF

PXD occupancy

2photon:0.8% (from 7th), SR:~0.1%*

< 3%

<3

CDC wire hit rate

~100kHz<200kHz2

CDC Elec.Borad n-flux*

0.8

<1

1

CDC Elec.Board dose

~20Gy/yr<100 Gy/yr

5

TOP PMT rate

2MHz/PMT<1 MHz/PMT

0.5

TOP PCB n-flux*

0.5

<1

2

ARICH HAPD n-flux*

0.65

<1

1

ECL crystal dose

13Gy/yr<10 Gy/yr

1

ECL diode n-flux*

1.2

<1

1

ECL pile-up noise

5/1MeV

0.8/0.2MeV at
Belle-I?

KLMs are not included
showing SF<5 only
(SVD is not shown ‘cause it’s very save)
Hiroyuki Nakayama (KEK)

With “combined”
shield inside ECL

20th ARC (Feb. 23-25, 2015)*neutron flux in unit of1011 neutrons/cm2/yr,
NIEL-damage weighted
32

x : positive=ring outer, y: positive=downward

inner
lower
upper
inner

lower

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)33

x : positive=ring outer, y: positive=downward

inner
lower

upper
upper

inner

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)34

Simulation Geometry
r14994ECL
shields(lead+poly)
CDC
neutronshieldARICH
neutronshields

Rough
RVC
structure

tungsten shields for VXD

Hiroyuki Nakayama (KEK)tungsten shields in QCS

20th ARC (Feb. 23-25, 2015)35

BG level with “1mm-wider” LER
collimators
SVD

TOP

ARICH

x100

ECL

Nightmare for any detectors. Note that collimator
precision is ~50um, so this should not happen!
IF such severe BG happens, we need to abort beams.
VXD radiation sensor can issue aborts, but it only sees
BG level in VXD volume. Outer detectors want to havetheir own BG monitors? (ECL dose monitor, etc.)

50um/100um/200um-wider
samples will be prepared

Characteristic BG hit distribution is seen for each of
H/V collimator open situation. This helps to detect
which collimator went wrong.

Question on Bhabha generator• So far we used BBBREM for BG campaigns– BBBREM: always emit 1 photon– Minimum Eg fraction= 1e-6  0.52 barn
– Only Elab(e+)<3.85GeV, Elab(e-)<6.85GeV are used
• Assuming small DE particles just go though QCS beam pipe

• All phase space contributing to detector BG iscovered by BBBREM?
– Elastic scattering?
– Large angle scattering with small DE?

Two generators for different phase space regions

These regions are carefully chosen
to avoid overlap between BBBREM
and BHWIDE

Included in next(12th) campaign

qscat (e+)

Detailed investigation
by C. Hearty (UBC)

1

1
0.5

2
0.5

1

3,4
qscat (e-)

Beam loss rate, weighted by beam energy

Gamma origin for TOP PMT hits.

r14994

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)39

Beam loss rate, weighted by beam energy

Gamma origin for TOP PMT hits.

r14994

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)40

r14994
Around z=500~650mm, beam pipe is
implemented as 5mm-thick Ta pipe.
In reality, there are- 18mm-thick Ta flange( z=464~482mm)- 18mm-thick Cu flange(z=482~500mm)
which gives further shielding effect.
However, BPM beam pipe are only 7mm-thickCu pipe and bellows are also thinner, which
gives more shower leakage.
I was aware these pipes are thin, and assumed
we are able to add some shielding here whichis equivalent to 5mm-Ta.
I will update basf2 geometry soon.

Cu BPMTa
flange flange
Hiroyuki Nakayama (KEK)

Bellows
20th ARC (Feb. 23-25, 2015)41

RBB shower on QCS front plate to TOP

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)42

P. Krizan at TOP review
in Nov. 2014

Strategy with PMT distribution

 We can run in such background conditions, but ~half of the PMTs will
have to be replaced.

How to distribute• normal type MCP PMTs (average max. charge ~1.1 C/cm2)• ALD type MCP PMTs (average max. charge ~8.6 C/cm2)
Decision:• Equip bar boxes with only one type of PMTs
Arguments• Experience in exchanging of PMTs in a bar box: few hours exercise• The main job will be to get access to the service hatch of the bar box
through cables, cooling etc of other detectors  we do not want to do it for
all boxes!
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

43

Backup SR

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)44

Y. Soloviev(DESY)

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)45

Y. Soloviev(DESY)

SR only!

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)46

Y. Soloviev(DESY)

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)47

Backup BEAST

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)48

Phase 1: BEAST Detectors
sensorcontact
personnumberLocation

DAQ

MeasuresPIN Diodes

D. Cinabro

64

decidedBEAST

X-ray & total
ionizing dose

Beam abort:diamonds, final
prototype

L. Vitale4

decidedBEAST

Total ionizing dose

BEAST

Fast neutron rate andrecoil spectrum(=directional info.)

decidedMicro-TPCs

S. Vahsen

2-4

He-3 tubes

S. De Jong /M. Roney4

decided

BEAST

Thermal neutron rate

BGO

J. “Terry”
Liau /
Min-Zu Wang8

decidedBEAST

EM particles ?

CsI Crystals (pureand Tl doped)

A. Beaulieu/ M. Roney

6 pure, 6
doped

decidedBEAST

EM particles

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)49

Phase 1 Detector Status• PIN Diodes– Amplifier rack boxes underconstruction, estimatedcompletion in February.

• Micro-TPCs– Two prototypes exist, to be
used in phase 1.
– Large x-ray flux in phase 1 may
saturation trigger. Working on
hardware veto.
– Vacuum vessel redesigned to
fit into VXD dock space.
Building 8 additional detectors
in 2015 (for phase 2)

PIN diode amplifiers at Wayne StateTPC vessel - final design.
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)50

Phase 1 Detector Status II•

He-3 tubes– 1st tube being shipped to Hawaii.
– Integrate into MiniBEAST in March.
– Remaining tubes being purchased.

•

BGO– Two crystals at Hawaii, getting
integrated into DAQ.
– Substantial work on DAQ
electronics, 2 and 8 channel
version– Critical issues:• Sufficiently sensitive for interestingmeasurements in phase 1? Can
optical coupling be improved?
• Still useful in phase 2 with material infront? With ECL present? Can VXDgroup accommodate back-to-backgeometry needed for electronposition coincidence measurement?
• NTU group to follow up withsimulation. Depends on VXD grouphelp regarding phi positions.

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

He-3 tube

BGO crystal supports
51

Phase 1 Detector Status III• CsI Crystals– Mechanical enclosure
being sent to Hawaii– Crystals have been secured– Italian groups toparticipate• Diamond Sensor Beam
Abort system– SVD, PDX Packages
developed– detailed characterization– DAQ developed

Holder for pair of CsI crystals.

12 x 20 x 3.1 mm3multi-layer package for SVD

Excellent progress by all groups building BEAST Detector systems - too much to report!
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)52

Phase 1
Dynamic Aperture & Touschek Lossbunch current = 1 mA

total loss/ring

Emittance ratio is variable.
53Beam-gas
Hiroyuki
Nakayama(KEK)
20th ARC
23-25, 2015) Touschek can also be varried.
BG
will vary by many orderof(Feb.
magnitude.

Phase 1 Simulation

I. Jaegle• We have a first phase-1 geometry and simulation in place(Jaegle, Ohnishi, Nakayama)• Predicts ~1000 x higher backgrounds levels in phase 1 thanduring phase 3, even at good (10-9 torr vacuum)• Different beam backgrounds have different φ & z dependence•First comparison of Touschek and Beamgas loss
distribution against MC may be achievable in phase 1• <= 1 week, at end of phase 1
likeneutron detectors once
Hiroyuki Nakayama•(KEK)If feasible, would
20th
ARCto
(Feb.move
23-25, 2015)54

What is the end of the phase-2
for the VXD commissioning
Important points to be considered:• Beam BG intensities on PXD and SVD.
–
–
–

•

DAQ and slow control software––•

temperature and humidity measurement

Noise performance on PXD and SVD––•

threshold determination and system reliability

CO2 cooling system–•

hit occupancy dependencealignment performance
available momentum (pT) in phase-2 VXD configuration?

Interlock system–•

Basically this check has to be done before phase-2 operation.
stability in real hits

Tracking and alignment performance.
–
–
–

•

also during injection
We will study them with PXD+SVD hit occupancies, monitor hits, MC simulation.
correlation between PXD+SVD HV currents and beam BG hit occupancy.

S/N on PXD and SVD.
Grounding

VETO gate in injection for PXD.
–

how to study it?

Example of discussion points from Nakamura San during BEAST Workshop 55
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)55

Request to Collaboration• To disentangle different beam background sources,
we’d like to reserve <2 weeks of phase 2• Dedicated measurements when varying accelerator
parameters (beam size, vacuum bumps, etc.)• Requirements– Belle DAQ operational, running in random trigger mode
– Belle DQM in place and available in EPICS– Stable accelerator and background conditions, rough beamcollimator adjustment completed• We suggest 1st week as soon as above is satisfied, 2nd
week towards end of phase 2. Prefer groups of 2-3 days
over continuous weeks.
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

56
56

PXD
•

contact person– C. Marinas•

motivation and brief analysis plan
–
–
–
–
–

•

hit occupancy and tracking study (ROI) under different machine configuration
spatial dependence of SR hits, injection BG
hit correlations with monitor sensors
injection VETO width study
CO2 cooling study, noise study

what kind of data to be stored on DAQ– same as phase-3•

designs of sensor/package/support– determined•

number and locations– determined: 2 ladders in 2 layers (0 deg. direction)•

cables and space for service– cables and cooling pipes (how many?)•readout system and DAQ– DCD, DHP, ONSEN (partial setup of phase-3), Belle II DAQ•

request for dock boxes– how many?

• request for Belle II clock, trigger, injection timing?
Hiroyuki
Nakayama
20th ARC (Feb. 23-25, 2015)• anyother(KEK)
requests

57

SVD
•

contact person–•

motivation and brief analysis plan
–
–
–
–

•

–

determined: 4 ladders in 4 layers (0 deg. direction)
cables (SVD-Dockbox: polyolefin 0.635 pitch 34 pair twisted-parallel):10 cables in FWD and 18 cables in BWD.
cooling pipes (1.6mm outer diameter SUS): 2 inlet-outlet pairs in BWD

Dock box

FADC system (partial setup of phase-3), Belle II DAQ

request for dock boxes–••

determined

readout system and DAQ–•

6 samples of ADC values from sensor strips with 25nsec sampling rate
above 0-suppression thresholds

cables and space for service–•

Junction boards

number and locations–•

v1.1.1

designs of sensor/package/support–•

hit occupancy and tracking study under different machine
configuration
spatial dependence of BG hits, injection BG
hit correlations with monitor sensors
CO2 cooling study, noise study

what kind of data to be stored on DAQ–•

K. Nakamura

1 box in FWD (2 junction boards), and 1 box in BWD (4 junction
boards).

request for Belle II clock, trigger, injection timing?
any other requests

Hiroyuki Nakayama (KEK)–

20th ARC (Feb. 23-25, 2015)

additional screw holes and alignment holes on FWD endflange58•contact person–•

12 x 10 x 3.3 mm3number and locations––•

charge amount accumulated for ??? usec.

designs of sensor/package/support–•

spatial dependence of BG hits and injection BG
hit correlations with PXD and SVD
interlock system test

what kind of data to be stored on DAQ–•

L. Vitale

motivation and brief analysis plan
–
–
–

•

diamond: 4 sensors on the beam pipe. Orientation (parallel or perpendicular to the beam pipe) is underdiscussion.
PIN diode: 64 sensors. All the sensors will cover the VXD volume.

cables and space for service–

2 cable for each sensor. In total, 4 cables for FWD and 4 cables for BWD.
•

•

???

request for Belle II clock, trigger, injection timing?
–•

AH501 for test readout. A new electronics with FPGA will appear. where?, Data will be stored in Belle II VXDEPICS DB.

request for dock boxes–•

3m coaxial thin (HS SM47LSFH) from sensors to DOCKs + 22m? HS S_04162-B60, double shieldreadout system and DAQ–•

diamond detector(+ PIN diode)injection timing?

any other requests

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

59

FE-I4 pixels•

contact person–•

motivation and brief analysis plan
–
–
–

•

???

request for Belle II clock, trigger, injection timing?
–

•

???

request for dock boxes
–

•

???

readout system and DAQ–•

3 arms are on 90, 180, and 270 deg.

cables and space for service–•

arm design has to be fixed. how are they fixed on VXD
structures ???

number and locations–•

hit position, hit timing, energy deposit ???

designs of sensor/package/support–•

hit occupancy under different machine configuration
spatial dependence of BG hits, injection BG
energy spectrum of SR hits

what kind of data to be stored on DAQ–•

C. Marinas

How does it get injection timing (FTSW signals)???

any other requests

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

60

CLAWS (Scintillator + SiPM)•

contact person– C. Marinas•

motivation and brief analysis plan
– spatial dependence of BG hits, injection BG•

what kind of data to be stored on DAQ– energy deposit, hit timing•

designs of sensor/package/support– Are they already fixed???

•number and locations– 2 ladders on 135 and 225 deg.

•

cables and space for service– cables ???

•readout system and DAQ– 6404D (PICOTECH) DAQ???

•

request for dock boxes– no•request for Belle II clock, trigger, injection timing?
– how does it get injection timing?

•

Hiroyuki Nakayama (KEK)

any other requests

20th ARC (Feb. 23-25, 2015)

61

Scintillator + PIN diode•contact person– H. Nakayama, K. Nakamura•

motivation and brief analysis plan
– spatial dependence of BG hits, injection BG•

what kind of data to be stored on DAQ– hit rate on scintillator, accumulated charge on PIN diode•designs of sensor/package/support– design of sensor/package are almost fixed. PIN diode is under discussion.

•

number and locations– under discussion (basically put around QCS)•

cables and space for service
– ???

•

readout system and DAQ– EASIROC (scintillator) and ??? (PIN diode). DAQ?

•

request for dock boxes
– ???

•
•

request for Belle II clock, trigger, injection timing?
any other requests

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

62

BGO
•

contact person– J. Liau•

motivation and brief analysis plan
– Bhabha scattering measurement (Luminosity measurement)•

what kind of data to be stored on DAQ– Energy deposits in crystals.

•

designs of sensor/package/support– Sensor and package are determined. Support is under discussion.

•

number and locations– 8 crystals (if space allows). Locations are under discussion. (Acceptanceoverlap issue with PXD cooling blocks.)•

cables and space for service– 1 fiber from each crystal. until where?

•

readout system and DAQ– where? BEAST DAQ•

request for dock boxes– ???

• request for Belle II clock, trigger, injection timing?
Hiroyuki
Nakayama(KEK)
20th ARC (Feb. 23-25, 2015)
• any
other
requests63

Temperature and humidity sensors•

contact person–•

L. Vitale

motivation and brief analysis plan

NTC sensors– temperature and humidity measurement in the VXD volume– interlock system test•

what kind of data to be stored on DAQ– temperature and humidity values•

designs of sensor/package/support– NTC (temparature), Vaisala DMT242B (Dew point)•

number and locations– not determined•cables and space for service
– ???

•

readout system and DAQ– where? Belle II VXD EPICS DB.

•

request for dock boxes
– ???

•
•

request for Belle II clock, trigger, injection timing?
any other requests

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)

Vaisala DMT242B
Dew Point Transmitters[-60, +60]oC dew point range
64

FOS + L-shape sensors•

contact person– I. Vila, D. Moya•

motivation and brief analysis plan
– temperature and humidity in the VXD volume– interlock?

•

what kind of data to be stored on DAQ– temperature, humidity, and deformation values•

designs of sensor/package/support– determined? (L-shape)•

number and locations– ???
– Does L-shape need end-ring and CFRP cone? Can L-shapebe put on SVD cartridge ?

•cables and space for service

CFRP Lshape

Fiber
egres
s
prote
ction

– ???

•

readout system and DAQ– where? Belle II VXD EPICS DB.

•

request for dock boxes– LC-LC connectors . (how many boxes???)••request for Belle II clock, trigger, injection timing?
any other requests

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)65

PLUME•

contact person– I. Ripp-Baudot•

motivation and brief analysis plan
– spatial dependence of beam BG hits•

what kind of data to be stored on DAQ
– ???

•

designs of sensor/package/support– Mimosa-26 2 x 6 x 0.7 x 10^6 pixels– baseline: PLUME-2•

number and locations– 1 ladder.
– baseline plan: behind CROWS, at r ~ 4-5 cm, but still under discussion.

•

cables and space for service– under discussion•

readout system and DAQ– VXD EPICS DB is preferable.
– BEAST DAQ?

•

request for dock boxes
– ???

•

request for Belle II clock, trigger, injection timing?
– injection timing, timestamp(KEK)• Hiroyuki
anyNakayama
other requests

20th ARC (Feb. 23-25, 2015)66

Phase 1

PIN Diode System
PIN Diodes

64 channels: 8 z-positions X 4 phi positions X 2 diodes (shielded+unshielded)

Phase 2

Hiroyuki Nakayama (KEK)
1/20/2015

Proposed diode pair positions

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

67
67

PIN Diodes System II• Lead: David Cinabro (Wayne
State)• Use PIN diodes, Siemens SFH
206K PIN to measureionizing radiation dose
• Inexpensive & robust• Successfully used in CLEO for~10 years and integrated adose of < 3 Megarads• Every 2nd diode (in phi)coated with gold-paint• Allows separating dose fromcharged particles and x-rays
CLEO Measurements
Synchrotron fan
Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

68
68

PIN Diode Status
•
•

•
•
•

8 channel prototype delivered, good
good performance with final cables
64 channels in rack-mount enclosure
being assembled at Wayne State– parts procured– assembly behind originalschedule due to lack of
manpower, but compatible with
new KEK schedule
Temperature monitoring essential order placed for commercial system
New Wayne State postdoc, now
resident in Hawaii, to integrate & test
Ship to send to Hawaii by February
2015, to KEK August 2015

Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

8 channel prototype

1m and 37m
cables giveconsistent
results
69
69

CsI Crystals• Plan to measure CsI BGs
using 4 pure CsI & 4
CsI(Tl) crystals in ECL
location• BEAST DAQ• Beam-gas & Touschek
only, unfocused beams– Checks whether simulation
can predict these two
background reliably– Provides data on pure CsI
advantage, needed for
Canadian calorimeter
funding proposals
Hiroyuki Nakayama (KEK)
1/20/2015

Holder for pair of crystal, preliminary mechanicaldesign by U. of Victoria.

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

70
70Motivation for Neutron Measurements• Neutron backgrounds highly penetrating; difficult to predict &measure accurately, caused problems already at Belle and Babar• Will be critical for Belle-II operation and lifetime• KLM deadtime, ECL electronics lifetime, TOP PMT lifetime• Idea: neutrons produced at specific loss-positions along the beamline. Fast neutrons preserve directional information and can bedirectionally reconstructed. Use them to “image” loss spots.

Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

71
71

Phase 2

Neutron Detectors• He-3 tubes and microTPCs in dock space• Complimentary
detectors– TPCs image direction ofincoming fast neutrons,
but detected rate is low– He-3 tubes measure rateof thermal neutrons,
which is highHiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

72
72

Jan 15th: Heroic CAD effort by Alexandre Beaulieu (Victoria) confirmed detectors fit into VXD docks.
Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

73
73

Measuring Individual Neutron BGs w/ TPCs
I. Jaegle (Hawaii)(note: Distributions normalized to same area)

Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

Directional detection
motivation
1.
Isolate neutrons coming
directly from beam lines(rather than re-scattered)2.
Measure neutron flux
versus polar angle (beamline position) validate/tune simulation• nominal beams:
RBB HER dominates measure• Run single beams• no RBB• measure
Touchek• vacuum bump measure
Coulomb
74
74

micro-TPC Detector Prototyping
He-recoil measured in HeC02
gas at p=1atm
L ~ 4 mm
E ~ 400 keV/c2

Hawaii

Source Absent

Mean directionof nuclear recoils
corresponds toneutron source location
Source Present

neutron source

Clear excess & peaks in expected direction!

Tiny pre-prototype demonstrated detection principle.
1/20/2015
Hiroyuki
Nakayama (KEK)

Sven 20th
Vahsen,Workshop
ARCStrasbourg(Feb. 23-25,
2015)

75

micro-Time Projection Chambers
TPC #1

Hawaii• Two constructed (forphase 1)
– Excellent performance inlab tests– Working on improved x-ray
rejection and better cableshielding to be ready forthe tough commissioning
environment• Eight remaining (forphase 2)
– Construct in 2015, to KEKMarch 2016 (needed
approx. January 2017)
Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

TPC #1
TPC #2
TPC #176
76

Phase 2

He-3 Tubes

Victoria

Clear response to neutron source observed. First tube being shipped to Hawaii now.
Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

77
77

Phase 2

BGO luminosity monitors

•
•
•
•
•
•

Eight BGO crystals (from Belle Extreme forward Calorimater)
To provide independent luminosity measurement via electron coincidence, radiative Bhabha events
Also can provide analog (real-time) back-ground level to SuperKEKB
Working prototype w/ electronics exists
NTU student visiting Hawaii tomorrow for integration first two BGO crystals into MiniBEAST
Need to finalize phase II mechanical mounts (SVD endrings)

Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

NTU

78
78

BEAST DAQ
P. Lewis (Hawaii)• Build pseudo-events independently of Belle• to accelerator EPICs at 1Hz. Also to mask control?
• timestamp for off-line comparison with Belle/accelerator data

Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

79
79

Raw and processed BEAST2 data
BEAST2 has no trigger and no events. DAQ is
asynchronous and slow:• PIN: raw ADC output sampled at
100kHz, averaged to ~1Hz
• BGO: fitted event peak amplitude withtimestamps, ~0.1s-level timing• He3: Pulses with time information,
timing resolution unknown• TPC: triggered events with pixel data(time, coordinates and charge), mslevel timing

P. Lewis (Hawaii)

Consequently, BEAST2 data will consist of:• Independent databases of raw detector
data [ROOT files]• Summaries and human-readable
processed data in “pseudo-events” in a
ROOT file• Pseudo-events will summarize detector
data for a fixed interval of time, i.e. 1
secondNote: If we want MHz rate sensor data, e.g. to study injection backgrounds, it will needto go via a different DAQ path. E.g. beam abort diamond sensors, ATLAS pixel modules.
Hiroyuki Nakayama (KEK)
1/20/2015

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

80
80

BEAST DAQ Location – 20-30 m from IP
Booked for STR
Utilities

Air Conditioner Unit

Utilities

Stair

EV

Booked for STR
Utilities• Phase 1: Cable space and DAQ space requests
out fortrays installed.
made, granted.Keep
Cable
Service Entrance
Loading Table
To Loading• Phase 2: Preliminary requests made,butDock
notgranted / agreed on, yet.
E-Hut

Chiller Units
Booked for STR
Utilities

KLM Working Area

ARICH Clean RoomCommon Stage

Belle

Booked for STR
Utilities

Common Stage

Reserved for
Accelerator Group
Accelerator Space

concrete shield wall

Hiroyuki Nakayama (KEK)
1/20/2015

Fence

20th ARC (Feb. 23-25, 2015)
Sven Vahsen, Strasbourg Workshop

concrete shield wall

81
81

Monitor DAQ diagram (outdated?)
KLM

Via Input Output Controller(IOC) on B3 control roomat ~1Hz

ECL
Belle2
NSM

PID

KEKB
EPICS

CDC
VXD
(EPICS)

hardwareabortacc. abort
moduleBP-BGmonVXD EPICS directly
connected to KEKBEPICS?

Software
abort

BEAST
DAQ

Hard-wired
abort cable

Abort
kickerLonger cableto tunnel
DCCT

Abort
loggers
Hiroyuki Nakayama (KEK)
1/20/2015

Record info. just before
abort (for 100ms) with
20th ARC (Feb. 23-25, 2015)
0.2/1Mz

Sven Vahsen, Strasbourg Workshop

Collimator
control

KEKB control roommonitors for BCG
8282

Mechanical Mockups
TPC
He-3

BGO
Small-scale mockups have been built to validate mechanical interfaces.
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)83Phase 1 staging area in Tsukuba Hall B4 (“KLM side room”)

CDC clean room

BEAST:
3.7m x 10m

KLM storage

Proposing to skip phase 1 assembly in KLM side room. All mechanics & DAQ will already
have
been
testedHiroyuki
Nakayama(KEK) in Hawaii. Still need KLM side room for receiving tests, repairs, staging.
84
20th ARC (Feb. 23-25, 2015)

Phase 1 Mechanical Design (Rosen)

•
•
•
•
•

Full 3D CAD exists (Rosen). Remaining work: Finalize CSI supports, cable strain reliefs
Will use concrete anchors. Rosen will drill. Accelerator group has approved, will help survey
Mockups of detector supports have been built (see previous B2GM)
All parts purchased
Will start cutting fiberglass and assemble in mockup “beast cave” at U. Hawaii next week
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)85

Phase 1 Mechanical Design (Beaulieu)

New addition to BEAST. Two crystals to Hawaii early 2015. Availability of crystals?
Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)86Phase 2 VXD Mechanics (Marinas talk)• Great progress on integrating VXD sensors, BGOs,
and FE-I4 sensors (x-ray measurements)• Important open questions –request EB guidance• Material (X0) allowance?
• Include PLUME ladders?

CAD by Ackermann

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)87Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)88

Hiroyuki Nakayama (KEK)

20th ARC (Feb. 23-25, 2015)89