The LNF test setup Status as of

Geometry of LNF setup Top and bottom trigger counters 4 KLOE-type tracking chambers One BESIII-(COMPASS-)type test chamber 580 mm 250 mm 70 mm

One BESIII-(COMPASS-)type test chamber 4 KLOE-type tracking chambers

The new BESIII-type test chamber, co-financed by INFN, IHEP and MAE

The cosmic trigger The 2 trigger counters for cosmic rays are 10 by 10 cm 2 scintillators (top PM HV: kV, bottom PM HV: -1.0 kV) PM signals from top and bottom are fed to CAEN N417 low-threshold discriminators, stretched to 200 ns and coincidenced The rate is  0.1 Hz, with a few % random triggers The coincidence output triggers the SRS readout (APV25 electronics from CERN) and an Agilent DSO-X 3034A for monitoring

Trigger NIM logicTrigger 27270

The gas system (Hdwr) The 2 gases (Ar and iC 4 H 10, isobutane) are in bottles in the gas house,  100 m away from the setup Two separate gas lines transport the gas to MKS mass flowmeters, read out by a 647C digital controller Mass flowmeter ranges are 500 (Ar) and 50 (iC 4 H 10 ) cm 3 /min, nominal resolutions: 0.1% of range The gas mixture used is (90±0.5) cm 3 /min (Ar) and (10±0.05) cm 3 /min (iC 4 H 10 )

Ar (Ch.1) and iC 4 H 10 (Ch.3) mass flowmetersThe gas mixing cylinder

The MKS 647C readout controller

Gas/HV software interlock Readings from the 647C serial ports reach a Moxa NPORT 5450 serial server, that emulates via Ethernet 4 serial ports to the slow-control PC The slow-control PC is a VirtualBox Windows XP, running on a Scientific Linux 6 DAQ PC In the XP subsystem, 2 LabView VIs (one DataSocket publisher and one subscriber) monitor and log to disk gas flow readings One additional subscriber VI implements a software interlock for the HV-controlling VI

The Moxa NPORT 5450 Serial Server, with its Serial Port inputs and Ethernet connection

The Windows XP VirtualBox: the monitor VI is a DataSocket publisher of date-stamped gas flow readings. The slow logger VI is a DataSocket subscriber that writes gas flows to disk. The Watchdog VI analyzes flow and current readings and publishes the Alarm flag, to which the HV slow control subscribes.

HV hardware Based on a CAEN SY1527LC crate, with 3 A1550P boards – 28 channels for the 4 tracking chambers from KLOE – 14 channels for one (later 2) test BESIII chamber For redundancy and crosscheck the HV state is echoed (and possibly killed in an emergency) using a local monitor and keyboard Channel currents (below CAEN system capabilities) are read by a 24-channel nanoAmperometer with 1 nA resolution (design by LNF-SELF service)

The CAEN controller with its Ethernet connection, and AUX video and keyboard cables. The SELF nanoAmperometer, with its CANBUS interface

The 7 “physical” HV channels of a GEM For each chamber we use 7 HV channels: Cathode HV GEM 1 “Up” HV GEM 1 “Dn” HV GEM 2 “Up” HV GEM 2 “Dn” HV GEM 3 “Up” HV GEM 3 “Dn” HV Anode (readout), GND 3/5 mm drift gap 2 mm gap 1 mm gap

The 7 logical HV channels of a GEM The 3 “GEM” potentials determine gain: – Gain 1 is (exp) function of (HV G1up -HV G1dn ) – Similarly for gains 2 and 3 – Overall gain = Gain1*Gain2*Gain3 The 4 “transfer” HV’s only move electrons to the next stage: – (HV cathode -HV G1up ) moves electrons away from cathode towards GEM1: this is called the “drift” field – Same for middle gaps – (HV G3dn -GND) moves electrons away from GEM3 to the readout layer: this is called “induction” field

The LabView VI for monitor and control of GEM channels. Communications with the SY1527LC crate are handled by an HV OPCServer low-level driver written by CAEN. This VI implements a gas/HV safety software interlock.

HV for tracking chambers “physical”Top/Mid/Bot (kV) V cathode-2.76/-2.75/-2.74 V G1 Up-2.46/-2.45/-2.44 V G1 Dn-2.17/-2.15/-2.14 V G2 Up-1.87/-1.85/-1.84 V G2 Dn-1.58/-1.57/-1.56 V G3 Up-1.28/-1.27/-1.26 V G3 Dn-1./-1./-1. These tables are kept for reference, they were used for the old KLOE2 gas mixture “logical”Top/Mid/Bot Drift1./1./1. kV/cm Transfer 21.5/1.5/1.5 kV/cm Transfer 31.5/1.5/1.5 kV/cm Induction5/5/5 kV/cm Gain 1295/295/295 V Gain 2290/285/285 V Gain 3280/270/260 V

HV for tracking chambers “physical”Top/Mid/Bot (kV) V cathode-3.49 V G1 Up-3.04 V G1 Dn-2.76 V G2 Up-2.16 V G2 Dn-1.88 V G3 Up-1.28 V G3 Dn “logical”Top/Mid/Bot Drift1.5 kV/cm Transfer 23 kV/cm Transfer 33 kV/cm Induction5 kV/cm Gain 1280 V Gain 2280 V Gain 3280 V Gas mixture: Ar-iC 4 H 10 90%-10%

The nanoAmperometer interface The LNF-SELF 24-channels nanoAmperometer, with a CAN-bus interface, is read via a Kvaser USBCanII by a LabView set of VIs For now, we monitor 15 channels – All 7 channels of the new BESIII test chamber – The 2 most critical channels of each tracking chamber: G3Up and G3Dn

The LNF-SELF nA-meter Partially funded by PGR00136 Italy-China MAECI program

In the plot on the left, current time-histories for 6 “tracking” channels: the peaks appear normally in the chamber ramp-up phase. In the plot on the right, the same for all 7 channels of the new BESIII test chamber

The tracking chambers The 4 tracking chambers are KLOE2-type, designed and made by a LNF-Bari collaboration Each chamber has X-Y orthogonal views, read by 2 APV25 chips, a CERN-RD51 project The active area is 128 strip wide in X and Y With 650  m strip pitch, the active area is 8.3·8.3 cm 2 wide

X- and Y-strip planes, each plane has 128 strips and is read out by 2 APV25 chips, yielding 128 charge values, for 27 time samples (25 ns apart)

The DAQ system The APV25 chips are connected to an SRS board via HDMI cables, design by CERN-RD51 The SRS board, in a custom crates, is read out by the DAQ PC via a common Ethernet port

The SRS crate, connected via Ethernet to the DAQ PC, running Scientific Linux 6 (DAQ and board-configuring software by CERN)

Trigger logic PMTop, discr.,100 ns PMBot, discr.,100 ns Scaler 1 Oscilloscope trigger Timing Unit ns Scaler 2 Trigger SRS Trig from prog (debug) Veto from prog (End DAQ) Timing Unit 1 2 ms

DAQ numerology and def’s X view, chip 6 Y view, chip 4 X view, chip 3 Y view, chip1 X view, chip 2 Y view, chip 0 x y z Y view, chip 5 X view, chip 7

Results from cosmic setup Request 2 hits in both top and bottom tracking chambers to define a cosmic track Plot in the test chamber the residual “expected-measured” Fit the residuals with a gaussian + 2 nd degree polynomial (no alignments made as yet) Hard to do in cosmic rays – No momentum cut... Expecting results from beam test very soon

Single-view plots  x 180  m  y ≈ 200  m