The LNF test setup Status as of 20160217

Geometry of LNF setup Top and bottom trigger counters 160 mm 4 KLOE-type tracking chambers 610 mm One BESIII-(COMPASS-)type test chamber 200 mm 160 mm

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

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

The cosmic trigger The 2 trigger counters for cosmic rays are 12 by 15 cm2 scintillators (top PM HV: -0.985 kV, bottom PM HV: -1 kV) PM signals from top and bottom are sent to CAEN N417 discriminators with threshold 60 mV, stretched to 20 ns and coincidenced The rate is 0.02 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 logic Trigger 27270

Trigger optimization The 2 PM signals and the 2 discriminated ones are acquired via the scope USB port (triggered by the PMs AND) and analyzed separately PM’s HV equalized looking at signal height Fraction of random signals evaluated fitting the time difference between discriminated signals

Upper PM signal and timing PM max signal from PM waveform scan 60 mV threshold PM time slewing: smaller signals lead to a delayed coincidence discr. time (ns) wrt coincidence

Lower PM signal and timing PM max signal from PM waveform scan 60 mV threshold PM time slewing: smaller signals lead to a delayed coincidence discr. time (ns) wrt coincidence

Smaller PM signals have worse time correlation. Below threshold are: 1) random with flat correlation And 2) real coincidences with wider time distribution

Fitting the fraction of casuals Events with high signal and good timing Events with smaller signal and less good timing Flat casual distribution, 0.2% in total range BUT: unknown fraction of cosmic showers, ineliminable…

The gas system (Hdwr) The 2 gases (Ar and iC4H10, 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 (iC4H10) cm3/min, nominal resolutions: 0.1% of range The gas mixture used is (90±0.5) cm3/min (Ar) and (10±0.05) cm3/min (iC4H10)

Ar (Ch.1) and iC4H10 (Ch.3) mass flowmeters The 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 the same 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 two) test BESIII chamber(s) 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 3/5 mm drift gap GEM 1 “Up” HV GEM 1 “Dn” HV 2 mm gap GEM 2 “Up” HV GEM 2 “Dn” HV 2 mm gap GEM 3 “Up” HV GEM 3 “Dn” HV 1 mm gap Anode (readout), GND

The 7 logical HV channels of a GEM The 3 “GEM” potentials determine gain: Gain 1 is (exp) function of (HVG1up-HVG1dn) Similarly for gains 2 and 3 Overall gain = Gain1*Gain2*Gain3 The 4 “transfer” HV’s only move electrons to the next stage: (HVcathode-HVG1up) moves electrons away from cathode towards GEM1: this is called the “drift” field Same for middle gaps (HVG3dn-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 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. “logical” Top/Mid/Bot Drift 1./1./1. kV/cm Transfer 2 1.5/1.5/1.5 kV/cm Transfer 3 Induction 5/5/5 kV/cm Gain 1 295/295/295 V Gain 2 290/285/285 V Gain 3 280/270/260 V These tables are kept for reference, they were used for the old KLOE2 gas mixture

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 -1. “logical” Top/Mid/Bot Drift 1.5 kV/cm Transfer 2 3 kV/cm Transfer 3 Induction 5 kV/cm Gain 1 280 V Gain 2 Gain 3 Gas mixture: Ar-iC4H10 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 mm strip pitch, the active area is 8.3·8.3 cm2 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)

DAQ numerology and def’s Y view, chip 7 X view, chip 5 Y view, chip 6 X view, chip 4 z y Y view, chip 10 x X view, chip 8 Y view, chip3 X view, chip 1 Y view, chip 2 X view, chip 0

Results from cosmic setup Request 2 hits in both top and bottom tracking chambers to define a cosmic track Plot in the other 3 chambers the residual “expected-measured” Alignment in X and Y (test chambers only) Fit the residuals with one gaussian Cosmic rays technique not ideal  No momentum cut Cosmic showers (?) Geometric mismatch PMs/ chambers …

Choose the right SRS timebin

X residuals External chambers errors unsubtracted

Y residuals External chambers errors unsubtracted

Fixing rotations takes lots of stat….

Fixing rotations takes lots of stat….