WBS 1 05 Commissioning Detector Specifications Design Sven

WBS 1. 05 Commissioning Detector Specifications & Design Sven Vahsen University of Hawaii

Talk Outline • Intro – US Project Scope – Super. KEKB commissioning schedule & Phases • Pre-prototype test results & Final Designs – Support Structure – PIN diode system – TPC fast neutron detectors • Summary 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 2

US Project Scope • Lead design, simulation, DAQ integration (off-project) • Construct support structure • Prototype & construct PIN-diode radiation dose monitoring system • Prototype & construct micro-TPC neutron monitoring system • Perform acceptance tests at KEK 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) Part of US Belle II Project 3

Latest Belle II Schedule • https: //docs. google. com/spreadsheet/ccc? key=0 Ap 1 u. ZWWWy 6 I 0 d. Fp. SZzl. MRlls. TU 9 D M 1 Y 1 Zj. Ba. N 1 o 3 NUE&usp=drive_web#gid=19 Key dates: Phase I (No QCS, No Belle Detector): Jan 2015 Phase II (QCS, Belle, no VXD): Feb 2016 Phase III (QCS, Belle, VXD): October 2016 (This plan has changed repeatedly. Our mandate is to be ready for any commissioning scenario. ) 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 4

Commissioning Detector Configurations Phase I Main task is vacuum scrubbing of beam pipe. No collisions. Belle will not roll-in. Support Structure and PIN diode system needed. 2 TPC prototypes will be deployed. 16 -17 January 2013 Phase II Belle rolled in. No VXD detectors. 8 Final TPCs needed. Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 5

Support Structure 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 6

Mechanics • Hawaii designs + builds phase I mechanical mounting structure • Lead: Rosen • (German VXD group + KEK taking on mechanical design for PXD/SVD/BGO mounting in phase II) Phase I 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 7

• PIN Diodes velcroed to beam pipe (not shown) • TPCs and other systems attached to fiberglass unistrut structure • simple, (very) inexpensive • can be reconfigured in minutes • non-magnetic • low activation TPC BGO 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 8

16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 9

PIN diode system 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 10

Phase 1 PIN Diode System Proposed diode pair positions Phase 2 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 11

Dose Monitoring System • Lead: David Cinabro (Wayne State) • Use PIN diodes, Siemens SFH 206 K PIN, to measure ionizing radiation dose • Inexpensive & robust • Successfully used in for ~10 years and integrated a dose of < 3 Megarads. • Every 2 nd diode (in phi) coated with gold-paint • Allows separating dose from charged particles and xrays CLEO Measurements Synchrotron fan 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 12

PIN Diode System Prototyping • Commercial preamp and readout boards (from Cremat) 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 13

Prototype System 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 14

Final System 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 15

DAQ for final system (off project) 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 16

TPC fast neutron detectors 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 17

Motivation for TPCs • Neutron Backgrounds – Difficult both to predict & measure accurately, caused problems already for Belle and Babar – Will be critical for Belle-II operation and lifetime • KLM deadtime, ECL electronics lifetime, i. TOP photocathode lifetime • Idea: neutrons produced at specific loss-positions along the beamline. Fast neutrons preserve directional information and can be directionally reconstructed. Use them to “image” loss spots. 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 18

How TPCs will be used • Commissioning phase II: He-3 tubes and micro. TPCs in dock space • Complimentary detectors – TPCs image direction of incoming fast neutrons, but detected rate is low – He-3 tubes measure rate of thermal neutrons, which is high 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 19

Recoil angle in Backward TPCs Correct rates, but low MC statistics Higher statistics & re-normalized 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) Directional detection motivation 1. Isolate neutrons coming directly from beam lines (rather than re-cattered) 2. Measure neutron flux versus polar angle (beam line position) validate/tune simulation • nominal beams: RBB HER dominates measure • Run single beams • no RBB • measure Touchek • vacuum bump measure Coulomb 20

TPC Pre-Prototypes • July 2013: Larger volume & less plastic • 5 x higher neutron detection efficiency • 10 x lower background rate Used for ~2 years of detailed performance measurements Used to demonstrate neutron detection with higher efficency Performance of these detectors studied in great detail, well understood Commissioning Detector TPCs : further scale-up in size to increase neutron detection efficiency 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 21

Demonstration of Directional Neutron Detection Source Absent Mean direction of nuclear recoils corresponds to neutron source location Source Present Nu cle ar r eco il He-recoil measured in He. C 02 gas at p=1 atm L ~ 4 mm E ~ 400 ke. V/c 2 eutron n g in m o c In neutron source 16 -17 January 2013 Sca tte red ne utr on Clear excess & peaks in expected direction! Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 22

Angular and Energy Resolution, Nuclear Recoils Po-210 α-source inside vacuum vessel. How well can we locate it? He. C 02 at p=1 atm σϕ= 1. 0° α σθ = 2. 2° • Selected events clearly point back to a single source • No BG after good-track selection • consistent with σφ, θ detector ~1◦ July 2013 Sven 2013 Vahsen 16 -17 January Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 23

Angular resolution versus “track size” Analytical “prediction”: σϕ~ σPOINT/(L√N) The above allows us to extrapolate our results to other energies and gas pressures 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 24 24

Technical Status • Pre-prototypes of micro-TPCs have met and exceeded all Key Performance Parameters • Documented in Technical Design Report 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 25

Final TPC Prototype Design Sensitive volume Field cage Charge amplification (GEMs) Charge Detection (Pixel Chip) Aluminum vacuum vessel 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 26

Final TPC Prototype Construction • • Design finalized Two final prototypes are in production Testbeam in 2014. Install two at KEK fall 2014, eight in 2015. Vacuum vessel 16 -17 January 2013 Field cage assembly Sven Vahsen, Belle II Directors Review (Pre CD-2/3) Final DAQ board 27

TPC Prototype Testing: Ongoing 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 28

Conclusion • WBS 1. 5 Technical Designs are Mature • Detector (PIN diodes and TPCs) performance demonstrated with (pre-)prototype systems – Satisfy all KPPs • Final systems: Same detections principles, scaled up – More channels for PIN diodes – Larger sensitive volume for TPCs • Project Ready for CD-2/3 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 29

BACKUP SLIDES 16 -17 January 2013 Sven Vahsen, Belle II Directors Review (Pre CD-2/3) 30

Recoil angle distribution in Forward TPCs Correct rates, but low MC statistics Higher statistics & re-normalized • nominal beams: RBB LER dominates measure • Run single beams • no RBB • measure Touchek • vacuum bump measure Coulomb

BEAST Subsystem • U. S. Contributions – PIN diode dose monitoring system (Wayne State) – TPC directional fast neutron detectors (Hawaii) dedicated talks • Non-U. S. Contributions – BGO crystal luminosity monitors (NTU) – He-3 tube thermal neutron detector (Victoria, Canada) – PXD, SVD ladders, beam abort, synchrotron spectrum measurements: VXD groups (Bonn, MPI etc)

BEAST DAQ & Control • Stand-alone BEAST DAQ proposed – ~1 Hz pseudoevents • Independent of Belle II Phase I

Introduction • Commissioning detector will characterize radiation near Super. KEKB interaction point during beam commissioning. • Sub-systems supplied by a number of Belle II institutes, mounted on common mechanical support structure. • WBS 1. 5 captures U. S. contributions to this effort “BEAST” - KEKB commissioning detector in 1998 – effort led by U. Hawaii

Commissioning Detector Objectives 1. Determine if dose rate safe for Belle II roll-in and later operation at design luminosity (Belle I: hole in beampipe and damage to silicon vertex detector) 2. Provide real-time measurements of luminosity and backgrounds (needed by Super. KEKB during beam commissioning) 3. Validate Belle II beam background simulation (Distinguish different beam background sources (Touschek, Radiative Bhabha, Beam-gas, Synchrotron) 4. System tests for Belle II (Beam abort system, moveable mask positions, pixel detector cooling, inner detector occupancies)