Time stamping with Time stamping with CAEN V1290NCAEN V1290N

BledBled, , 2626thth – 28 – 28thth March 2008 March 2008

DuDušan Ponikvar, Dejan Paradižšan Ponikvar, Dejan ParadižFaculty of Mathematics and PhysicsFaculty of Mathematics and Physics

Ljubljana, SloveniaLjubljana, Slovenia

Present statePresent state

We have connected CAEN V1290N We have connected CAEN V1290N time-tag time-tag module with CAEN V1718 USB-VME interface module with CAEN V1718 USB-VME interface and can control both units using Linux based and can control both units using Linux based PCPC

We have prepared the software in “C” for We have prepared the software in “C” for reading and evaluation of resultsreading and evaluation of results

We have tested the setup using high stability We have tested the setup using high stability generators and GPS based 1PPSgenerators and GPS based 1PPS

49991600

49991700

49991800

49991900

49992000

1 2501 5001 7501 10001 12501 15001 17501 20001

T for periodic pulsesT for periodic pulses

Input is 20000 Hz from Agilent function generator HP33250Input is 20000 Hz from Agilent function generator HP33250

Jitter specifications (rms): 100ppm + 50ps = 5nsJitter specifications (rms): 100ppm + 50ps = 5ns

CAEN 1290N internal clock of 40MHz usedCAEN 1290N internal clock of 40MHz used

Measurement duration: 1sMeasurement duration: 1s

Deviation: +/- 125psDeviation: +/- 125ps

T [ps]

Sample number

100ps

T for 1pps pulses from HP33250T for 1pps pulses from HP33250

Input is 1 Hz from Agilent function generator HP33250Input is 1 Hz from Agilent function generator HP33250

Jitter specifications (rms): 100ppm + 50ps = 100Jitter specifications (rms): 100ppm + 50ps = 100s s

CAEN 1290N internal clock of 40MHz usedCAEN 1290N internal clock of 40MHz used

Measurement duration: 2 hoursMeasurement duration: 2 hours

Deviation: +/- 50nsDeviation: +/- 50ns

999835850000

999835900000

999835950000

999836000000

999836050000

1 601 1201 1801 2401 3001 3601 4201 4801 5401 6001 6601 7201 7801

T [ps]

Sample number

50ns

T for 1pps pulses from GPST for 1pps pulses from GPS

Input is 1PPS from GPS Input is 1PPS from GPS

Jitter specifications (max): +/- 150nsJitter specifications (max): +/- 150ns

CAEN 1290N internal clock of 40MHz usedCAEN 1290N internal clock of 40MHz used

Measurement duration: 1,5 hoursMeasurement duration: 1,5 hours

Deviation: +/- 100ns after initial warming-up periodDeviation: +/- 100ns after initial warming-up period

999830700000

999830750000

999830800000

999830850000

999830900000

999830950000

999831000000

999831050000

999831100000

999831150000

999831200000

1 601 1201 1801 2401 3001 3601 4201 Sample number

T [ps]

50ns

HardwareHardware

Signal sourcesSignal sources

CAEN inputs are CAEN inputs are connected to signal connected to signal sources using home-made sources using home-made TTL to NIM translatorTTL to NIM translator

PC is a Linux based PC is a Linux based machine, disk HD is an machine, disk HD is an integral part of the PCintegral part of the PC

PCHD

GPS1pps

“Photon”pulses

US

B-V

ME

CA

EN

171

8

CO

UN

TE

RC

AE

N 1

29

0

TT

L-N

IMH

OM

E

SYNC 20kHz

RS232

The The softwaresoftware consists of two parts: consists of two parts:

1.1. Data from CAEN to disk: Data from CAEN to disk: on-line data streamingon-line data streaming

2.2. Data from disk to evaluation: Data from disk to evaluation: of-line evaluationof-line evaluation

SoftwareSoftware

PCCAEN HD

PC

USER

HD

CAEN V1290NCAEN V1290N

V1290N uses 21 bit counter, clock frequency is 40MHz: counter V1290N uses 21 bit counter, clock frequency is 40MHz: counter period equals 52period equals 52ss

Continuous storage mode is usedContinuous storage mode is used

Result is the state of the counter at the arrival time of the Result is the state of the counter at the arrival time of the electrical pulse: 5 bit identifier (00000) + 5 bit channel electrical pulse: 5 bit identifier (00000) + 5 bit channel number + 21 bit number + 21 bit time-tagtime-tag

Results are grouped in CAEN internal buffer and periodically Results are grouped in CAEN internal buffer and periodically transferred to PC using USB bulk transfertransferred to PC using USB bulk transfer

Counter state

t

2 -121

0

CAEN V1290NCAEN V1290N

Periodic synchronization pulses are applied to V1290N spare input Periodic synchronization pulses are applied to V1290N spare input to identify counter periodsto identify counter periods

Frequency must be at least 20kHzFrequency must be at least 20kHz

Lots of sync pulses!Lots of sync pulses!

What we expect to What we expect to time-tagtime-tag is: is:- few thousands (up to 10k) pps “photon” pulses, - few thousands (up to 10k) pps “photon” pulses,

- 20k sync pulses and - 20k sync pulses and - 1PPS from GPS - 1PPS from GPS ----------------------------------------------------------------- ----------------------------------------------------------------- our system can cope with itour system can cope with it

PCPC

Linux based PC is used to collect measurement Linux based PC is used to collect measurement results and store them to diskresults and store them to disk

Maximum throughput of the system is about Maximum throughput of the system is about 100.000 pulses per second when our software is 100.000 pulses per second when our software is running at high priority running at high priority

File size is 100MB maximum, therefore results of File size is 100MB maximum, therefore results of the measurement must be stored in several the measurement must be stored in several consecutive filesconsecutive filesPC hardware specifications: PC hardware specifications:

AMD Athlon(tm) XP 1700, AMD Athlon(tm) XP 1700, 512MB memory512MB memory

Hardware builtHardware built

CAEN 1290N requires NIM standard inputs: a 4 channel TTL to NIM CAEN 1290N requires NIM standard inputs: a 4 channel TTL to NIM translator was built, since this was faster than buying ittranslator was built, since this was faster than buying it

CAEN 1290N requires positive differential ECL inputs for sync clock CAEN 1290N requires positive differential ECL inputs for sync clock of 40MHz: a logic level translator was built for the same reasonof 40MHz: a logic level translator was built for the same reason

ImmediateImmediate plans plans

We currently have some problems with the GPS We currently have some problems with the GPS 1PPS output: antenna? Old GPS? Warming?1PPS output: antenna? Old GPS? Warming?

We need to introduce 1PPS sync pulses into We need to introduce 1PPS sync pulses into CAEN 1290N no problemCAEN 1290N no problem

We need to include RS232 output from GPS We need to include RS232 output from GPS (time stamp) into streamed file with CAEN (time stamp) into streamed file with CAEN 1290N measurement results to identify absolute 1290N measurement results to identify absolute time no problemtime no problem

Testing with better clock and GPS systemTesting with better clock and GPS system