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J-PARC DAQ WS Oct. 14, 2005. Hypernuclear g Spectroscopy Experiments and Waveform Readout of Germanium Detectors H. Tamura Tohoku Univ. Present Status and Hyperball2 DAY-1 experiment Hyperball-J – Readout and DAQ. Present Status and Hyperball2.
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J-PARC DAQ WS Oct. 14, 2005 Hypernuclear g Spectroscopy ExperimentsandWaveform Readout of Germanium DetectorsH. TamuraTohoku Univ. • Present Status and Hyperball2 • DAY-1 experiment • Hyperball-J – Readout and DAQ
Present Status and Hyperball2
The bible for nuclear physics PLB 579 (2004) 258 PRC 65 (2002) 034607 We want to publish “Table of Hyper-Isotopes” Nucl.Phys.A 754 (2005) 155c Nucl.Phys.A 754 (2005) 155c Present status of hypernuclear g spectroscopy PRL 93 (2004) 232501
Motivation of Hypernuclear g Spectroscopy High-precision (DE~a few keV) spectroscopy with Ge detectors 1. YN, YY interactions -> Unified picture of B-B interactions, Understand short-range nuclear forces LN spin-dependent forces, LL force, … Understandhigh density nuclear matter (n-star) 2.Impurity effects in nuclear structure Changes of size/shape, symmetry, cluster/shell structure,.. B(E2) -> shrinking effect 3. Medium effects of baryons probed by hyperons B(M1) -> mLin nucleus At a short distance
Hyperball(Tohoku/ Kyoto/ KEK, used in 1998-2002) Side view BNL E930 setup
Hyperball2 • Single Ge (r.e.=60%) + BGO(6PMT) x14 Clover Ge (4ch) (r.e. >120%) +(BGO(12PMT)) x6 Ge: 38 ch, BGO: 156 ch • Peak eff. ~ 2.5% -> 5% at 1 MeV gg efficiency x 4 • Used at CYRIC (Tohoku) for ordinary nuclear g spectroscopy 2005.6--7 • Being used at KEK for E566 (g spectroscopy of 12LC / 11LB) 2005.9--10
Hyperball2 at KEK-PS K6 Line (E566) Hyperball2 SKS K6 Q10
K1.8 + SKS pK= 1.1 and 1.8 GeV/c or Proposal for DAY1 “Hypernuclear g Spectroscopy by (K-,p- g)” K1.1+ SPESII pK= 1.1 and 0.8 GeV/c spin-flip non-spin-flip • Light (survey study) ・ A=4-~30 all possible targets 4LHe, 13LC/ 14LN, 20LNe, 23LNa, 27LAl / 28LSi, … (-> Table of hyper-isotopes, LN interaction, ...) • Light (detailed study for some important hypernuclei ) ・ gg coin, qgp/ qgg, polarization -> level scheme, spin-parity ・ DSAM -> B(E2), B(M1) • Hyperfragments ( K-, gg (p-) ), 0.8 GeV/c ・ Light targets (9Be,10B, 11B, 12C) 7LHe, 8LLi, 8LBe, 9LLi, 9LB,... (LS, CSB,..) • Medium and heavy p=0.8--1.8, large q -> large q ・E1(pL->sL) ~4 MeV 89LY, 139LLa, 208LPb (p-wave LN int.,..) 12LC (parity mixing states), 20LNe (parity inversion),.. 9LBe (B(E2)), 13LC (B(E2)), 11LB (B(M1)), … Total beam time to be estimated.
K- 1.1 + 0.8 GeV/c Beam and Setup (K1.1 case) • Beamline: K1.1 1.2x107 K-/spill at 1.1 GeV/c K/p > 1 • Spectrometer: SPESII Dp/p < 2 MeV (FWHM) W ~ 20 msr • Hyperball-J e ~ 10% at 1 MeV p-
12C (p+,K+) 12LC SKS DE~1.5 MeV(FWHM) (1-b) Light hypernuclei --- example of 12LC Simulation: K1.1, 10g/cm2, 120 hours a l Expected transitions c b g d k h p f k o e j n i h g j e c b m f i d l a
c gg coincidence and angular correlations coinc. with a (21- ->11- ) k h j f qpg angular correlation -> spin assignment 12LC: simulation gg coincidence spectrum -> level scheme coinc. with c (12- -> 21- ) h k
●(Segmented) Super Clover (350%) x 14 (or normal x 32?) + old normal (60%) x8 ●Waveform readout ●Fast suppression counters (BGO=>PWO) Hyperball-J • e ~ 10% at 1 MeV (x4 of Hyperball) • Rate limit ~2x107 particles /s (x5 of Hyperball) => Yield: x20 for single g x80 for gg PWO
Readout electronics at present Low-Gain Transistor Reset Preamplifier • Reset level ~150 MeV, 6V (gain~40mV/MeV) • Fast reset time (~5 ms) • Resolution 2.2 -> 2.6 keV at 1.33 MeV Ultra-High-rate Amp • Pile up time = integration time (3 ms) << normally: shaping time (3-6 ms) x10 • Fast recovery from reset (~15 ms) • Resolution 2.2 -> 2.6 keV at 1.33 MeV pileup reset • Dead time = 6 ms x 50 kHz + 20 ms x 10 kHz 30% + 20% = 50% • Trigger Rate ~ 500/spill(1 sec) x 2 k words in total
Example of Ge signals at a high rate K6 (E566), 3Mp/1.5s, 15cm from beam beam penetration pile up reset baselineshift shaper overload Shaper (0.5ms) out GI bad GI dead GI dead Gated integrator (GI) out Preamp inhibit
waveform digitizer ~14bit ~40MHz Pileup decomposition and baseline correction by software Goals: single rate:100->500kHz, energy rate 0.5->2.5TeV/s beam limit: K6: 3x106/sec -> K1.1: 1.5x107/sec Waveform readout method Usual waveform method (Digital Signal Processor) eg. XIA DGF Shaping, PZC, PH-ADC, time stamp Processing speed 200k ev/s (We may use this waveform digitizer but we should make software by ourselves.) Preamp. gain 40mV/MeV , Dynamic range 150 MeV-6V Required resolution < 1 keV = 0.04mV -> Digitizer resolution 150,000= 18bit -- impossible
slow waveform digitizer slow amp t ~1ms >12bit ~40MHz TFA t ~0.1ms Multi-hit TDC CFD low-gain transistor-reset preamp Hardware: technically OK, cheaper Waveform readout method – our case We will take sample data in E566 with existing hardware -> software development -> optimize digitizer parameter -> Design hardware CFD out High energy bg.~50 MeV Simulation (slow signal) Nuclear g-ray bg. ~1 MeV 4ms 1ms 2ms
Trigger rate and Data rate • Channels Ge: 134 -- 64 ch, waveform (13bit,20MHz) + multihitTDC PWO: 200--300ch, TDC + ADC • Trigger rate (very rough estimate) AGS D6(E930): 200k K-/spill, (K-,p-) tirg= 900 trig/spill, x 0.3 by Ge-hit OR -> J-PARC (K1.1): 9M K-/spill, Hyperball-J x 0.3 -> 0.7 28000 trig/spill (At K1.8, K- intensity at 1.1 GeV/c is one order lower.) Sever beam-through veto, sever Cerenkov cut to remove K decay x 1/2 PWO suppression in the trigger level x 1/3 PWO total-energy/multiplicity cut (remove p0) x 1/5 ? + Energy deposit tag (enhance hypernuclear events) if necessary Trigger rate < 1000 trig/spill • Data rate Waveform: [13bit x 20MHz x 20ms ] x ( 5--20 Ge’s) x 1000 trig/spill ~ 2--8 kw/ev x 1000ev/spill = 4--16MB/spill Others: < 1kw/ev : negligible 2nd level 1st level 2ndlevel 1st level 2nd level 1st level Transfer data for Ge without PWO hit
Things to be done • Development of waveform analysis software -> How much improvement in high rate performance? -> Optimize digitizer parameters (resolution, sampling) • Shaper + Digitizer module Data transfer should be controlled using PWO info. • Data transfer scheme, Memory modules • “TFA with good BLR (equiv. ORTEC 579) + CFD” module or another digitizer (8bit,~100MHz) for timing info.? • Trigger PWO discri. + FPGA module (TUL) ? PWO multiplicity: OK, PWO energy sum: + Linear F/I • Control / diagnostics module (HV control, alarm, Co pulsers,..)