BLM AUDIT 2010Ewald Effinger BE-BI-BL BLM tunnel installation and data acquisition card (BLECF) Ewald Effinger AB-BI-BL

Ewald Effinger BE-BI-BLBLM AUDIT 2010

BLM tunnel installation and data acquisition card (BLECF)

Ewald Effinger

AB-BI-BL


Outline

• Introduction: the BLM System• Tunnel hardware installation• The data acquisition card (BLECF)• Irradiation and additional tests• Test of the monitors and cables• Test of the acquisitions card• Commissioning of the complete BLM system• Tests during operation • System changes due to internal Audit 2008


Introduction: the BLM System

• 3893 Ionization chambers (IC)• 289 Secondary emission monitors (SEM)• 3 Little Ionization chambers (LIC) (for test measurements) • 669 HV distribution boxes (BJBHT)• 309 Signal patch boxes (BJBAP) • Signal cables for 3m up to 800m length



• 669 BLM data acquisition cards (BLECF)– In the arc the cards are installed underneath the magnets

in a 19’’ create– In the straight section the cards are installed in the nearby

side-tunnels, because of reduced radiation level



• Optical links are connected to 342 threshold comparators (TC) with an optical receiver card on the surface

• 25 VME creates are distributed around the LHC• Each create includes a PowerPC (data logging), a Combiner card

(connected to the beam interlock system), and two timing cards (CISV, CTRP, BOBR)

• USB connected system for test and development

Courtesy of C. Zamantzas


Tunnel hardware installation

Grounding scheme

• Shielded signal and high voltage cables

• Floating ground to avoid ground

loops



• Schemes of the arc installation

– 6 Ionization chambers

– Filter capacitors and resistors are installed in the IC

– Signal cable length 3 to 11m



• Schemes of the straight section installation

– Ionization chambers

– Filter capacitors and resistors are installed in the IC

– Signal cable length up to 800m



• Schemes of the collimation installation

– Ionization chambers and secondary emission monitors

– Additional 150kΩ resistor installed

– Filter capacitors are installed in the BJBHT

– Signal cable length up to 600m



• Schemes of the dump installation– Ionization chambers and secondary emission monitors– Additional 150kΩ resistor is used in the IC– Filter capacitors are installed in the BJBHT– Filter installed before the BJBAP


Specification of the acquisitions card

• Radiation tolerant up to 500Gy (20 LHC lifetime)• Reliability level SIL3 ( 10E-6 to 10E-7 failure/h) to damage of

equipment• Current measuring range 2.5pA to 1mA• Accuracy 25% in the range from 1mA to 1nA• Accuracy 100% in the range from 1nA to 10pA• Integration time window 40us• Input current protection ~ 10A @100us• Input voltage protection ~ 1500V @100us• Redundant optical data transfer to surface• Test features for system check• Survey of the card voltage supplies• Survey of detector high voltage supply


The acquisitions card

Essentials of the input circuit• Current to frequency

converter (CFC)• Balanced charge integrator• No charge loss (“no blind

time”)• Very large dynamic range• Output frequency depends

on input current

Switch

Iin(t)

Referencecurrent

Tresholdcomparator

One-shotT

Iref

Integrator

fout

Switch

Iin(t)

Referencecurrent

Tresholdcomparator

One-shotT

Iref

Integrator

fout

Input Current Output frequency

1mA 5MHz

1uA 5kHz

1nA 5Hz

1pA 5mHz



Measures to fulfill the specification• Irradiation of single components (JFET, OP, Comparator, One shot, …)• Insertion of fast protection diodes, high voltage capacitors, and leaded

resistors on the input • ADC added to decrease response time / increase dynamic range• Automatic feedback loop with DAC to compensate leakage current due to

integrated dose

U nom. = 1500V

Tested with puls 10A@100us

Tested with puls 1500V@100us12 bit ADC AD41240

8 bit DACA5346

No changeNo change

-30 to -80pA

140pA

No change

At 500Gy



• 8 current inputs (CFC)• ADC AD41240 CERN

ASIC • LM4140 voltage

reference• FPGA for data combiner • Two redundant GOH from

CMS (including CERN ASIC)

• Line driver CRT910 CERN ASIC

• DAC AD5346



• Actel antifuse FPGA A54SX72A

• 4024 sequential cells

• 2012 combinational cells

• Total logic usage: 85%

• Pin usage: 100%• 40 MHz clock



GOH 1

GOH 2

CFC

Tripled Inputpins

CFC Counter Ch1 - Ch8

( 8 times )

8 bit counter

2 out of 3

Timing, monitor

and control - signals

Input C

Count Q1

2 out of 3

8 bit counterInput B

8 bit counterInput A

Count Q2

Count A

Count B

Count C

• Tripled redundant logic• 2 x 2 out of 3 voter connected to two GOHs


Irradiation and additional tests

• Energy : 251.63 [MeV]• Run time : 4488 [sec]• Fluence : 9.712e+11

[p/cm2]• Dose : 4.914e+04 [rad]

• Flux : 2.164e+08 [p/cm2/sec]

• Doserate : 1.095e+01 [rad/sec

• FPGA irradiation up to 491Gy, no corrupt data package received (CRC Error =0)



• Single component irradiation tests

• 54SX72A (FPGA), malfunction at 480 to 790Gy, no SEP detected up to 1x 10¹² p/cm²

• 74HCT123 (one shot), malfunction at 300 to 350Gy components recovered when not irradiated

• All other components were working up to 1500Gy



• Installed test system at HERA, no CRC error occurred for several months

• Temperature test: 0 – 70C passed

• Magnetic field test: 1000Gauss passed, performed for CMS


Test of the monitors and cables

• All ionization chambers checked with a radioactive source in the Gamma Irradiation Facility (GIF)

• All secondary emission monitors are checked with a radioactive source in the GIF and with beam in H4

• All the cabling is tested for conductivity with a current source

• All the cabling are tested for leakage current with a pico ampere meter


Test of the acquisitions card

• All inputs of the acquisition card are calibrated in two steps– Maximum current 1mA with Keithley current source– Minimum current 10pA with open inputs

• Automatic final check test of the acquisition card with the BLECFT system– Verification of the calibration and input linearity (10

steps)– Complete functionality of the FPGA including status

bits, HV comparator levels and CRC check


Commissioning of the complete BLM system

• Tunnel check test of the acquisitions card– Each acquisition card is checked after the installation

in the tunnel with the BLECFT system

• Verification of the signal path of the complete system– Introducing of signal current using a 137CS source on

each ionization chamber– Verification of the signal in Control room display and

database, with a crosscheck of the layout database


Tests during operation

• Constant 10pA offset current - Check on channel availability

- In case of exceeding limits (no count for more than 100s), a beam dump can be generated

• Continuous status monitoring - Monitoring of voltage supplies and other

status information (CFC- Error, Integrator Level, Temperature, High voltage level)

- Should failure occur, a beam dump can be generated



• Continuous check during data transmission

- Checked at each transmission

* Card identity number check

* Frame identity number check

* Cycle redundancy check

- Should failure occur, a beam dump can be generated



High Voltage (HV) activation test and HV modulation test

• 100pA added, dynamic test

• Capacitive current injection via chamber electrodes

• Degradation of complete chain can be detected

• In case limits are exceeded, no beam permission given

• To be carried out before each beam fill


System changes due to internal Audit 2008

Spare production of tunnel equipment

• Production of 100 BLECF launched • Purchase of LSS power supplies• Spare production of tunnel chassis

Additional irradiation test of the BLECF and power supplies

• Irradiation in neutron beamo 5.551 E12 Neutrons/cm2 o Card was still working and no SEU observed

• Irradiation in mixed filed beam in the CNGS test facilityo Total dose of 270Gyo 64.95 1MeV eq. neutrons [1e11*cm-2]o 45. 76 Hadrons>20MeV [1e11*cm-2]o Card was still working and no SEU observed

Ewald Effinger BE-BI-BL

Implementation of a general power reset of the BLECF

• Mezzanine PCB added in all BLECF electronic and tested

• General reset possibility (per point) with to High voltage distribution (operational)

• Separate reset possibility (per BLECF) via WorldFip distribution (partly operational in point 6)

BLM AUDIT 2010

System changes due to internal Audit 2008


Measurement results

CFC input circuit• Dynamic range

over 8 decadesfrom 1mA to 10pA

• Specified error 100%

• Down to 1nA max error of 6.5%

• Down to 10pA max error of 96%

Output frequency = f (Input current)

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.0E-11 1.0E-10 1.0E-09 1.0E-08 1.0E-07 1.0E-06 1.0E-05 1.0E-04 1.0E-03

I in [A]

f o

ut

[Hz]

Channel 2 Channel 4

Channel 6 Channel 8

Documents

BLM AUDIT 2010Ewald Effinger BE-BI-BL BLM tunnel installation and data acquisition card (BLECF) Ewald Effinger AB-BI-BL