1 MICE Tracker Update M. Ellis UKNFIC Meeting 25 th August 2005

2 Story so far...  2003/2004: Three station prototype assembled and operated at D0 using D0 equipment.  February 2005: Sci Fi/VLPC technology validated for MICE tracker  March – August: Work on new hardware (4 th station, cryo-cooler & cryostat, AFEII prototype, Avnet, etc) for MICE tracker, leading towards:  October 2005: Test beam at KEK

3 Previous test  Used a D0 test cryostat, able to hold two VLPC cassettes (4 AFE boards).  Only had access to two AFE (version 1) boards, so readout 1024 channels.  Software used was Excel/Visual Basic code in regular use at D0 for testing of AFE and calibration of VLPCs/AFE boards.  Need MICE specific hardware and software!

4 Fourth Station  New specification (changed fibre pitch).  Improved optical connector design.  Station constructed at IC and new tracker assembled in dark-room at IC.  CMM machine used to determine station alignment.  Complete tracker made light-tight and shipped to Fermilab..

5

6 Analog Front-End (AFE) Version 2  New design of the readout electronics for VLPCs.  Step along the path to AFEII-t, which will add the ability to record TDC information for each hit.  Prototype AFEII boards have been used for the first time at D0 for work on the MICE tracker.

7 MICE tracker readout with VLPCs Tracker Waveguides AFEII boards VLPC cryostat LVDS cables to VLSB module

8 VLPC operating conditions  Temperature needs to be kept at 9.00 ± 0.02 K.  Cryostat/cryo-cooler combination controlled to hold cold-end at 6.8 K with heater on a feed- back loop.  VLPC cassettes have 8 heaters, controlled through the AFE board, that bring the temperature up to 9.0 K and maintain it.  Select appropriate bias voltage to optimise gain vs noise rate. Optimisation depends on expected data-taking rate.  Bias voltage is applied through the AFE board.

9 LVDS / VLSB  Low Voltage Differential Signaling (LVDS) is used to transfer the ADC data from an AFE board to a VME memory module.  The cable is connected to the AFE board through the AFE back-plane.  VME LVDS Serdes Buffer (VLSB) boards are VME devices containing memory and an LVDS interface.  When the AFE board passes through a data- acquisition cycle, the ADC values are sent to the corresponding VLSB board and can then be accessed over a VME/PCI interface (BIT3).

10 LVDS and VLSB Trigger/Timing LVDS cables VME/PCI 1553 VLSB modules

11 Initialisation  AFE boards need to be initialised before data-taking can begin.  This is achieved through the Mil-1553 interface. One 1553 can control all 4 boards on a MICE 2-cassette cryostat.  Initialisation includes: FPGA power on, programming and testing FPGA power on, programming and testing Trigger Pipeline (TRIP) chip programming Trigger Pipeline (TRIP) chip programming VLPC bias voltage and temperature control VLPC bias voltage and temperature control

12 Timing and Triggering  FPGAs require a 53 MHz clock.  AFE board has a number of operating modes: Initialise Initialise Acquire Acquire Digitise Digitise Readout Readout  The clock and mode control used to be provided by a “SaSEQ” board, now provided by an “Avnet” board.  Avnet is able to control all 4 boards on a MICE cryostat at once and requires no software intervention to perform a trigger/acquire/digitise/readout cycle.

13 Avnet Board Connection to AFE Backplane External trigger RS232 cable

14 Readout Sequence  External trigger is generated (e.g. cosmic ray trigger scintillators).  Trigger is ANDed with a pattern that matches the tevatron bunch structure (needed for now, will be replaced in later use for MICE).  If trigger is accepted, signal is passed to Avnet board.  Avnet board causes the AFE boards to acquire, digitise and readout the data to the VLSB modules and then sets the AFE boards ready for the next trigger.  Data is retrieved from the VLSB modules over the VME/PCI interface to a Linux PC.  Timing is critical as the trigger signal to the Avnet board needs to arrive 7 “bunch crossings” after the light from the tracker arrives at the VLPCs.

15 Progress at FNAL  After a lot of problems, have managed to operate the MICE cryostat with 4 AFEII boards.  Linux software written for MICE can now perform almost all of the initialisation sequence and was used for all data-taking.  Took data with an LED pulser attached to each VLPC cryostat in turn and then connected the tracker and collected a few thousand cosmic ray triggers!  Tracker system is currently on its way to Japan...

16 G4MICE  Several new features have been implemented in preparation for the use of G4MICE in data-taking and analysis of the KEK data: User applications User applications A few SciFi classes are now persistent A few SciFi classes are now persistent Interface to CERNLIB to make PAW histograms, etc Interface to CERNLIB to make PAW histograms, etc Code to decode raw data format Code to decode raw data format

17 Pedestal Widths Made with G4MICE

18 Calibrations – Cassettes 105 & 111 One channel from each cassette. Note 105 has a gain of ~20k and 111 has a gain of ~40k Made with G4MICE 10 PE

19 High Gain Cassette – More Light Made with G4MICE

20 Calibration Results Made with G4MICE

21 First look at Cosmic data  Still require work on “cabling” information (i.e. which board/channel/MCM is connected to which Station/Plane/Fibre)  First look involves selecting channels with a good calibration and plotting ADC distribution in units of Photo Electrons.  More refined analysis requires use of G4MICE (coming very soon...)  Light is seen coming from the tracker:

22 Cosmic Ray data  Pedestals subtracted  No Common Mode Noise subtraction  Gains used to express ADC as PE  No tracking or other cuts  All channels with a signal above 2.0 PE are shown

23 Next Steps  Work ongoing in G4MICE to allow all future calibration/alignment and analysis to be performed using G4MICE.  Need to sort out channel map and attempt tracking using G4MICE.  Prepare Linux software to control Avnet board and finalise newer TRIP programming scheme (much faster).  Take data at KEK...