CDC Summary Shoji Uno (KEK) July-8, 2009

Baseline Design Belle sBelle

Tentative drawing by Kohriki-san

Connection regions 1 Endplate and Outer cylinderMain and Conical (Backward)

Main and Conical Connection regions 2 ForwardBackward

Conical and Small cell Small cell and Inner cylinder Connection regions 3

Wire tension and gravity sag Nanae Taniguchi (KEK)

8 sag calculation tension (total tension) 80g (4.4 ton) 100g (5.2 ton) 120g (6.2 ton) sag(field) - sag(sense) 84.8μm28.4μm-9.2μm sense wire : 30μm, 50gw wire length : 2.4 m y horizontal cell

9 wire tension and gravity sag Current Belle CDC wire tension is determined to keep the gravity sag of sense and field wire same 50gw for sense wire and 120gw for field wire total tension = (50gw x 8400) + (120gw x 8400 x 3) = 3.4 ton Belle-II number of sense wire: 8400 →15104 total tension = (50gw x 15104) + (120gw x x 3) = 6.2 same weight reduce total tension : 120gw → 80gw (base line design), 6.2 ton → 4.4 ton however difference of gravity sag is larger

10 HV=2.3kV (sense wire) B = 1.5 T C 2 H 5 :50% He:50% simulation using Garfield 10 ±0.1mm

11 current Belle position resolution ~ 100μm -0.1mm +0.1mm tension (total tension) 80g (4.4 ton) sag(field) - sag(sense)84.8μm sense wire : 30μm, 50gw (x: distance from sense wire at nominal case)

Mechanical calculations of the CDC end-plates KEK H. Yamaoka July 8 th, '09 KEK H. Yamaoka

Material properties Load conditions Constraints R: Free  : Fixed Z: fixed RotR: Fixed Rot  : Free RotZ: fixed Total: 3725kg Definitions for FEM No inner cylinder

2.9mm 2.7mm 31MPa Results - End-plates: 10mm-thick(Al), Outer-cylinder(CFRP): 5mm-thick. Deformation Stress Deformation Stress <107Mpa : allowed limit <5mm : Belle-CDC

Material: CFRP Dia. 340mm Length: 1000mm E ： 110GPa : 0.3 t=0.4mmt=0.8mm Buckling strength: Inner cylinder Wire tension : 371kg Safety Factor : 6

Readout board space Test board 16ch  48ch(~300boards in total) 20cm 17.5cm Should be fit in volume

CDC readout system status MT 2009 July 7

Test board for test(prototype readout card will be designed based on this.) Small tube chamber (tungsten wire) Fe keV X-ray Gas(Ar90%+CH 4 10%), P10 Gas 1.65kV 16ch Ampshaper AD9212x2 TDC&L1 buf RocketIO RMS=0.47ns This AmpShaper was developed for other application. Modification will be done by Dr. Taniguchi. FPGA-TDC has been used for J-PARC. Firmware design will be done by Dr.Uchida PCB was designed by Mr. Saito and Mr. Ikeno RocketIO will be tested by Dr. Igarashi

FPGA Block diagram FADC I/F ADC TDC ASD Ring buffer 5usec 500nsec window Readout FIFO Q(sum) & Data formatter SiTCP Or RocketIO I/F Slow control DAC, ADC, Ring buffer etc Trigger

Pre-AMP test Nanae Taniguchi (KEK)

21 pre-Amplifier Hybrid (NEW + ) Rise time is limited by chamber signal → not need to be so fast → lower electric power The modified PZC cause noise Found overshoot

22 set up small tube chamber p10 gas (Ar 90% + CH 4 10%) Fe keV X ray (~3xMIP) HV = kV (below saturation point) make uniform each pulse height

23 signal shape Belle AMP 12dB 13dB 3dB 1dB Hybrid (NEW + ) make uniform each pulse height with attenuator

24 definition Resolution = Noise level = Fit to Fe 55 data with Double Gaussian Fit to pedestal data with Single Gaussian pedestal (random TRG) Fe 55

25 comparison AMP resolution[%] noise level[%] Hybrid (NEW + ) 3rd and 4th Hybrid AMP have lower noise Noise level is enough low resolution is worse in actual situation

26 set up Timing resolution measurement with pulse generator TDC 500ns range 0.125ns/ch start stop 51Ω 1kΩ 0.1μF

27 Resolution Fit to data with Double Gaussian Resolution is calculated as weighted sigma TDC range 500ns 0.125ns /ch TDC distribution

28 comparison Resolution [ns] AMP rise time ~20ns~ 40ns Hybrid (NEW + ) 4th Hybrid AMP is comparable with (better than) Belle AMP

Summary of ADC/TDC measurement 4th Hybrid AMP is usable for base design We discuss about parameters for prototype of ASIC AMP with T-Taniguchi-san (electronics group) We will have meeting again before making ASIC pre-AMP another plan of TDC measurement using TUAT signal from chamber master student is working for the test Finally, We must do beam test with ASIC AMP MIP signal and He/C 2 H 6 gas

Schedule(short term) Firmware w/o rocket IO Amp shaper Test with rocket IO End of Aug. prototyping End of Sept. Nov. modification Preparation for beamtest Design and feedbacksubmission PCB design Uchida Taniguchi, Shimazaki Nakao, Igarashi Saito, Ikeno

My Personal Plan for Construction

Backup

Main parameters Present Future Radius of inner boundary (mm) Radius of outer boundary (mm) Radius of inner most sense wire (mm) Radius of outer most sense wire (mm) Number of layers 5058 Number of total sense wires Effective radius of dE/dx measurement (mm) Gas He-C 2 H 6 Diameter of sense wire (  m) 30

Introduction Mechanical calculations of CDC end-plates was carried out. Load: Wire tension  ~4000kg in total. Material: Outer cylinder  CFRP End plates  Aluminum, CFRP Assumption: All wire tension is supported by the outer cylinder. CDC End-plate Deformation(< 5mm), Stress? Buckling strength? ~R1090 ~2400

Wire configuration Given by Taniguchi-san

Distributions of wire tension in R-direction

37 Wire tension and gravity sag small gravity sag, large total tension distance between sense wire and field wire has z-dependence asymmetric electric field asymmetric X-t curve same distance from sense wire(x), different drift time affect the position resolution gravity sag field sense field r horizontal cell

38 δx nominal move sense wire position by amount of +/- 0.1mm put an electron along x-axis calculate the distance from sense wire and drift time obtain X-t curve calculate δx δx is difference of x at same timing

39 current Belle position resolution ~ 100μm -0.5mm +0.5mm -1.0mm +1.0mm -0.1mm +0.1mm tension (total tension) 80g (4.4 ton) sag(field) - sag(sense)84.8μm sense wire : 30μm, 50gw (x: distance from sense wire at nominal case)

Calculation of deformation and etc Deformation of Aluminum endplate Thickness of endplate 10mm Tension of field wire 120g  80g Gravitational sag, Sense : 190  m(50g), Field:300  m(80g) Unequal sag  Nane-san’s talk Total tension ~4ton Deformation  Yamaoka-san’s talk Stress calculation Thickness of outer cylinder CFRP ： mm Transition structure between endplate and outer cylinder Bucking calculation for inner cylinder Larger tension for many wires ( ~400kg) Yamaoka-san’s talk

Weight Endplate Al, Thickness : 10mm 110kgx2 = 220kg Outer Cylinder CRRP, Thickness : 5mm 210kg Electronics Board G10, 48ch/board 0.3kgx315 = 95kg

Wire configuration So far, 8(A),6(U),6(A),6(V),6(A),6(U),6(A),6(V),8(A), 58 layers in total But, Readout board 64ch/board 16x4  No good assignment 48ch/board 16X3 8(A)  2(A)+6(A) inner most super layer 2(A)  special treatment 160x2=320 : 48x7=336 8(A)  6(A) outer most super layer 56 layers in total  Good assignment Other good idea is highly welcome.

Calculations of buckling strength Ref: E.H.Baker, et. al. 'STRUCTURAL ANALYSIS OF SHELLS'  The buckling strength of the outer/inner cylinder is calculated.

Assumptions Material: CFRP Dia. 2190mm Length: 2328mm E ： 110GPa  : 0.3 If t=5.0mm If t=1.0mm Wire tension : 3725kg Buckling strength: Outer cylinder

Calculation results in various parameters Allowable stress （ Japanese: Koukozo sekkei kijun ）  This criterion was used for the mechanical design of the Belle.

- If deformation has to keep less than 5mm, thickness of end-plates should be thicker than 7mm(Al).  Calculation at the practical configuration will be necessary. - To know the mechanical properties of CFRP is important,  We have contacted to a CFRP fabricator. Configuration END Conclusion Made by Kohriki-san

層 R(mm) Z+(mm) Z-(mm) 数 角度 1 A A A A A A A A U U U U U U A A A A A A V V V V V V A A A A A A U U U U U U A A 層 R(mm) Z+(mm) Z-(mm) 数 角度 41 A A A A V V V V V V A A A A A A A A 張力分布 ( リスト ) Z+ 内筒なし Z+ R+(X+)

Prototype CDC readout card (FY2009) # of channels(Total: ～ 15000) 48 ～ 64ch/board Amp shaper Shaping time: ～ 100nsec Gain: ～ 1V/1pC （ TBD) Dynamic range:2pC （ TBD) TDC  FPGA TDC Timing resolution:1nsec ADC Resolution:10bit Sampling rate: ～ 32MHz L1 buffer Depth:5usec max Test board was developed to determine above params using test chamber.

Specification of Test board(detail) Analog(Amp-shaper for DB-decay exp) Peaking time: ～ 50nsec  OK Pulse width: ～ 200nsec  OK Gain : 8V/pC  1 ～２ V/pC Dynamic range : 2V max  OK Noise : ～ pF  OK Function ADC 10bit 32MHz TDC 1nsec L1 buffer : 5usec max Two modes for data format Waveform data readout mode Compression mode Timing and Q These values will be confirmed by beam test BLR modification has been done

Amp shaper modification CMOS digital BLR Analog buffer Amp shaper Bias circuit Present Amp shaper We started development of Amp-shaper for BELLEII CDC.

Function L1 buffer length : 5usec Max variable New old Trigger Window(for Q info:  ) 500nsec variable Timing data and Q or waveform data are Transferred to external interface ADC waveform Comparator output Data format will be determined within a month

52 AMP study Determine parameters for prototype of ASIC AMP Test some kinds of Hybrid AMP before making ASIC Compare with current Belle AMP Belle-II AMP is required to be comparable or better than current one purpose

53 signal shape Belle AMP 12dB 13dB 3dB 1dB each pulse height corresponds to that of Fe 55 X-ray signal at kV rise time ~ 20ns and ~ 40ns Hybrid (NEW + ) pulse generator (reverse) same pulse for all AMP

conclusion parameters of prototype ASIC are almost decided base design of Wire tension are determined structure analysis by H. Yamaoka-san Wire configuration and Endplate under discussion now Plan structure test of CFRP

conclusion parameters of prototype ASIC are almost decided base design of Wire tension are determined structure analysis by H. Yamaoka-san Wire configuration and Endplate under discussion now