Gotthard related stuff

Version 9.1 by sndueste on 2023/06/20 12:33
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Info related to the Detector



Ethernet connections:

  • gbit port  <--->  Server PC (hasfl2det01 at FLASH2, no server currently at FLASH1)
  • base-T     <--->  Office net

How to use the Detector and save in DAQ

for now very short: run the Exp2 DAQ with EXPERIMENT_GOTTHARD included as shown below. AND press the start button in the Gotthard DAQ (you get there from the Gotthard panel lower left button "Gotthard DAQ"


  • Main Gotthard panel for users :

Clipboard05.gif


  • Exp2 DAQ RC gui for recording Gotthard data. EXPERIMENT_GOTTHARD has to be included

Clipboard01.gif


Modules and their exchange

Two (Three) modules available (physically at FLASH):

hostname

Status

Sensor

Sensor image

config file

cfeld-gotthard02

standard/online/working

two small areas of damaged pixels

cfeld-gotthard02.jpg

bchip_mpc1922Receiver.config_cfeld-gotthard02

hasdslabgh

working

first 1/3 is blind, strong base line offset in the center and a further blind bunch and the end

hasdslabgh.jpg

bchip_mpc1922Receiver.config

cfeld-gotthard01

was working (2018), backilluminated! the sensor front is Al-shielded for x-rays

?


bchip_mpc1922Receiver_petra.config


To change a module the respective config file has to be selected. However changing it will crash the server, thus, it is not possible to change on the fly. Connact Sören if there is the need to exchange a module. However, the differences in the configs are only the hostname. (To be tested: On the fly might work, if one edits the config-file itself after switching of the server instead of selecting another config file in the GUI. But how to transport this information to the GUI? → Display the first line of the config file!) The config files are located at the hasfl2det01: /export/doocs/server/gotthard_server/cfgs/


GOTTHARD Server

The server for GOTTHARD (FLASH2) runs on hasfl2det01. Its watchdog and control (svr.GOTTHARD) can be found under FLASH.SYSTEMS - HASFL2DET01.


Main Parameters and limits

Parameter

Design

Real /tested

Max Frames

125

120

Max. exposition time

~2/3 of period time


Min. period time

ca. 930 ns


Max repetition frequ.

1 MHz

833 kHz (software limited)


Soft reset a GOTTHARD Module

  • Open console on Linux PC (connected to DESY net)
  • write "telnet cfeld-gotthard02" (or the respective Host name or IP of the module)
    • you should be connected to the GOTTHARD onboard system → </root:
  • type: "reboot"
    • the module reboots (wait ~1-2 min), the telnat connection will be cut due to reboot.


Triggering the Gotthard with a burst trigger

it is also possible to trigger the Gotthard not only with 10 Hz but with a burst trigger 

here are some Info from PIS (June 2023)

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I think one does not need to set it in GUI when running in continuous mode. In G1, whether the detector is running in burst or continuous mode depends on the setting of the "number of frames" in trigger mode. If the number of frames sets to 1, it will be in continuous mode (1 trigger -> 1 frame).

Since G1 accepts triggers from the lemo connector, one can also use the bunch train trigger. The spacing of the trigger train needs to be larger than 3.2 ms, which is the readout time of G1.

Regarding the detector setting (assuming it is 200 kHz pulse rate, 100 pulses per train):

  • timing mode: trigger
  • number of frames: 1
  • number of triggers:  M x N (M is the number of trains and N is the pulses per train, one can also take a bit more frames per train to track the pedestal/dark)
  • period: < 5 us (1/200 kHz = 5 us, the period needs to be slightly smaller than 5 us since the detection of the trigger only starts after the period is reached)
  • exposure time: > 93 ns and smaller than period

Alignment: One of the four lemo connectors on G1 outputs its exposure window. Using an oscilloscope, one can use a photodiode under the beam and align the pulses from the diode and the exposure window of G1 by fine tuning the exposure time of G1 and/or the setting of "delay after trigger" from the detector, or "delay time" of the wave-generator (if a wave-generator is used to generate the triggers for every pulse). After this, one can do a fine scan of trigger delay to find an optimal setting with highest signal after putting G1 under the beam.


by:

Dr. Jiaguo Zhang

Paul Scherrer Institut

Forschungsstrasse 111

5232 Villigen PSI

Switzerland