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Standard beamviewer (EBV: ESRF Beam Viewer)

Screenshot

EBV is an instrument to visualise the various types of x-ray beam (white, pink and monochromatic) into the visible spectrum, using a scintillator, a camera and associated software to measure the beam shape and relative power intensities. The maximum accommodated beam size (or potential beam movement) is 10mm x 10mm for the standard beamviewers.

EBV is an assembly of various modules:

  • a Control Box (ISG made)
  • a fixed giga-ethernet basler camera+lens
    • powered by the Control box
  • an extractable head that can be moved in or out of the beam (called screen)
    • pneumatic-mounted mirror+scintillator
    • scintillator
      • diamond for white beam
      • YAG for monochromatic beam
      • Energy dependent for pink beam
  • a diode read by novelec module providing an output in frequency.
  • a LED that can be switched ON and OFF.
  • optionnaly: a foil to attenuate beam (on MX beamlines)

References

BCU wiki: http://wikiserv.esrf.fr/bliss/index.php/Bvb

Control

The EBV BLISS object controls the wago box (screen, led, foil, diode), the basler camera and the associated BPM counters computed on images.

Wagobox modules

Two type of wago box exist:

  • 1-EBV wagobox able to control only one EBV :

    • 750-436 : 8-channel digital input; 24VDC
    • 750-530 : 8-channel digital output; 24 VDC; 0.5 A
    • 750-479 : 2-channel analog input module (ADC)

  • 2-EBV wagobox able to control up to 2 EBV:

    • 750-436 : 8-channel digital input; 24VDC
    • 750-530 : 8-channel digital output; 24 VDC; 0.5 A
    • 750-530 : 8-channel digital output; 24 VDC; 0.5 A
    • 750-479 : 2-channel analog input module (ADC)

If the EBV has a foil to attenuate beam (MX case), two additionnal wago modules are added:

  • 750-436 : 8-channel digital input; 24VDC
  • 750-504 : 4 Channel Digital Output

Configuration

Configuration example

plugin: bliss                 (mandatory)
name: myebv                   (mandatory)
class: EBV                    (mandatory)
modbustcp:                    (mandatory)
    url: wcidxxa              (mandatory)

single_model: False
has_foil: False
channel: 0
counter_name: mydiode

camera_tango_url: idxx/limaccds/bv1

  • modbustcp / url defines the wago control box host as in standard wago controller.

  • camera_tango_url defines the limaccds Tango device server of associated Basler camera.

Configuration optionnal parameters

  • single_model

    • default value : False
    • define which model of wago is used : if single_model is True, the wago box is a 1-EBV model otherwise it is 2-EBV model. Note that some 2-EVB models can be installed even if it controls only one BVB.

  • has_foil

    • default value : False
    • define if a foil attenuator can be controlled or not

  • channel

    • default value : 0
    • in case of a 2-EBV wago box model, defines which EBV is used : 1st one or 2nd one.

  • counter_name

    • default value : diode
    • counter name of diode current reading when EBV is used in counts/scans

  • camera_tango_url

    • default value : None
    • if provided, the EBV will be extended with the BPM powers (Bpm measurements and BeamViewer Live display)

Usage

Global status

BLISS [16]: myebv
  Out [16]: EBV [myebv] Wago(wcid21bv1)
                screen : IN
                led    : ON
                foil   : NONE
                diode range   : 1mA
                diode current : -0.351451 mA

            Bpm [id21/limaccds/bv1]

                exposure : 1.0 s
                size     : [1024, 1024]
                binning  : [1, 1]
                roi      : [0, 0, 1024, 1024]
                flip     : [False, False]
                rotation : NONE

SCREEN control

BLISS [12]: myebv.screen_in()
BLISS [13]: myebv.screen_status
  Out [13]: 'IN'

BLISS [14]: myebv.screen_out()
BLISS [15]: myebv.screen_status
  Out [15]: 'OUT'

LED control

BLISS [22]: myebv.led_on()
BLISS [23]: myebv.led_status
  Out [23]: 'ON'

BLISS [24]: myebv.led_off()
BLISS [25]: myebv.led_status
  Out [25]: 'OFF'

FOIL control

If EBV has no foil, foil_status returns None: 

BLISS [26]: myebv.foil_status
  Out [26]: 'NONE'

Trying to use it will raise error: 

BLISS [27]: myebv.foil_in()
!!! === RuntimeError: No foil on EBV [myebv] === !!!
BLISS [28]: myebv.foil_out()
!!! === RuntimeError: No foil on EBV [myebv] === !!!

EBV with foil: 

BLISS [12]: myebv.foil_in()
BLISS [13]: myebv.foil_status
  Out [13]: 'IN'

BLISS [14]: myebv.foil_out()
BLISS [15]: myebv.foil_status
  Out [15]: 'OUT'

DIODE current reading

The current diode value is returned always in mA 

BLISS [39]: myebv.current
  Out [39]: 1.52587890625e-06

Raw reading of the underlying wago without gain correction is accessible by myebv.raw_current. The value returned is in the 0-10V range.

DIODE range control

Changing diode range using string format: 

BLISS [41]: myebv.diode_range_available
  Out [41]: ['1mA', '100uA', '10uA', '1uA', '100nA', '10nA']

BLISS [42]: myebv.diode_range
  Out [42]: '10uA'

BLISS [43]: myebv.diode_range = "100uA"
BLISS [44]: myebv.diode_range
  Out [44]: '100uA'

Floating value of gain used to convert reading to mA can also be accessed via: 

BLISS [44]: myebv.diode_range
  Out [44]: '100uA'

BLISS [45]: myebv.diode_gain
  Out [45]: 10.0

BLISS [46]: myebv.diode_range = "10nA"
BLISS [47]: myebv.diode_gain
  Out [47]: 100000.0

Setting the floating gain is possible. Range will be chosen to include the maximum desired gain given: 

BLISS [48]: myebv.diode_gain = 500
BLISS [49]: myebv.diode_range
  Out [49]: '1uA'

BLISS [50]: myebv.diode_gain
  Out [50]: 1000.0

EBV and BPM counters

The BPM counter controller is accessible via the EBV object in Bliss.

BLISS [51]: myebv.bpm
  Out [51]: Bpm [id00/limaccds/simulator2]

                exposure : 1.0 s
                size     : [1024, 1024]
                binning  : [1, 1]
                roi      : [0, 0, 1024, 1024]
                flip     : [False, False]
                rotation : NONE

The EBV owns all BPM counters and the diode counter. 

BLISS [51]: ct(1, myebv)
Tue Mar 31 16:43:52 2020

 acq_time = 1.038032054901123 ( 1.038032054901123/s)
   fwhm_x = 99.04761904761904 ( 99.04761904761904/s)
   fwhm_y = 99.04761904761904 ( 99.04761904761904/s)
intensity =         99.2 (        99.2/s)
        x =        512.0 (       512.0/s)
        y =        512.0 (       512.0/s)
ebv_diode = -0.15674306466872268 (-0.15674306466872268/s)

Bpm measurements reading

Measure and return data (timestamp, intensity, center_x, center_y, fwhm_x, fwhm_y) 

BLISS [53]: myebv.bpm.raw_read()
  Out [53]: [array([1.0819428]), array([99.2]), array([512.]),
             array([512.]), array([99.04761905]), array([99.04761905])]

Visualization

The command myebv.show_beam will start/raise Flint and display a live preview from the EBV camera.

To stop the live, just close the tab in Flint.

If a scan is started, the live is automatically stopped first.

A single snapshot can be performed with the command myebv.bpm.snap()

Some parameters of the underlying camera can be read or write:

myebv.bpm.exposure = 0.01           # (sec)
myebv.bpm.bin = [2,2]               # (xbin, ybin)
myebv.bpm.roi = [100,200,300,300]   # (xpos, ypos, width, height)
myebv.bpm.flip = [True, False]      # (LR, TB)
myebv.bpm.rotation = 'None'         # in ['None', '90', '180', '270']

BPM Controller (camera only + BPM measurements)

Single cameras which are not part of an EBV set (i.e without the Wago part for the control of the LED/Foil/Screen) can be used to perform BPM measurements.

A standalone BpmController object can be associated to the camera and created from the configuration files like this:

name: mybpm
plugin: bliss
module: ebv
class: BpmController
camera_tango_url: idxx/limaccds/camname

EBV counters

The EBV has 6 sampling counters (1 for the diode and 5 for the Bpm measurements):

  • myebv.diode
  • myebv.x
  • myebv.y
  • myebv.fwhm_x
  • myebv.fwhm_y
  • myebv.intensity

myebv holds all 6 counters wheras myebv.diode returns only the diode counter.

The Bpm measurements will be performed using the current CCD exposure and image parameters (bin, roi, flip, rotation).

The camera trigger mode is forced to INTERNAL_TRIGGER and camera mode to SINGLE.

If the scan count_time is longer than the ccd exposure the Bpm measurements are sampled as many times as possible.

Note

the default counter name for the diode is diode but it can be changed in the configuration file.

BLISS [51]: ct(1, myebv)
Tue Mar 31 16:43:52 2020

 acq_time = 1.038032054901123 ( 1.038032054901123/s)
   fwhm_x = 99.04761904761904 ( 99.04761904761904/s)
   fwhm_y = 99.04761904761904 ( 99.04761904761904/s)
intensity =         99.2 (        99.2/s)
        x =        512.0 (       512.0/s)
        y =        512.0 (       512.0/s)
ebv_diode = -0.15674306466872268 (-0.15674306466872268/s)



BLISS [52]: ct(1, myebv.diode)
Tue Mar 31 16:54:15 2020

ebv_diode = -0.1567430646687215 (-0.1567430646687215/s)