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====== µCT ======

===== X-Ray Source =====

==== PXS5-724EA Microfocus Source ====

* 20kV-70kV targe voltage
  * 0-0.1 mA beam current
  * 10µm x 10µm focal spot on tungsten target
  * 34° (or 40°) cone angle
  * 0.13mm Beryllium windows

==== Connector ====
  - Chassis Ground
  - 4.0V DC kV Control Source
  - HV Programming (4.0V = 80kV)
  - HV Programming Ground
  - Current Programming (2.5V = 100µA)
  - Standby Power (+12V DC)
  - HV Monitor Voltage (4.0V = 80kV)
  - Current Monitor (2.5V = 100µA)
  - Monitor Ground
  - +2.5V DC mA Control Source
  - +12 DC Operate Power
  - DC Operate Ground

Mating Connector :
  * Plug: TE 206037-1 (https://www.digikey.de/product-detail/de/206037-1/A1304-ND/15600/?itemSeq=355426273)
  * Pins: TE 1-66101-9 (https://www.digikey.de/product-detail/de/1-66101-9/A31988-ND/808380/?itemSeq=355818573)
  * Backshell: TE 206322-9 (https://www.digikey.de/product-detail/de/206322-9/A33767-ND/1124058/?itemSeq=355818490)

==== Thoshiba DGO 73 ====
  * 65kV
  * 8mA beam current
  * 700µm x 700µm focal spot
  * 2mm Aluminium filter (integrated in tube?)

===== X-Ray Detector =====

==== Dexis Platinum / GXS-700 ====
  * SN: 0104430711
  * 19.5µm x 19.5µm Pixels
  * 1324x1692 Resolution
  * Sensor Firmware Version: 0.5.10, 0.3.6, 0.4.5
  * CPLD Version: 3.3.0.0
  * API Version: 1.0.10.0
  * VID 5328 PID 2010

* SN: 1093330312
  * 19.5µm x 19.5µm Pixels
  * 1552x1040 Resolution

[[https://nucwiki.org/wiki/index.php/GXS700_FOSS]]

[[https://nucwiki.org/wiki/index.php/Gendex_GXS700]]

[[https://nucwiki.org/wiki/index.php/Gendex_GXS700_Dump]]

[[https://github.com/JohnDMcMaster/gxs700]]

==== DigiPan ====

* 1244 x 61 pixels
  * 104µm pixel pitch
  * 12bits per pixel
  * 1 Start bit, 1 Control bit (always 1)

https://hackaday.io/project/62710-taking-digital-xray-shots-for-cheap-300

=== Connector ===
  - (BL) Ground
  - (RD) +5V
  - (OR) +15V
  - (GR) -15V
  - (BL) RS422 A
  - (WH) RS422 B

==== Flatpanel Detector ====

==== Fluorescent Screen ====

===== Mechanics =====
==== Stepper Motors ====
=== GRBL ===

https://github.com/gnea/grbl/wiki/Grbl-v1.1-Configuration
==== A4988 ===
https://lastminuteengineers.com/a4988-stepper-motor-driver-arduino-tutorial/

== Step Mode ==
^ MS1  ^ MS2  ^ MS3 ^ Mode  ^
| GND  | GND  | GND | 1/1   |
| VIO  | GND  | GND | 1/2   |
| GND  | VIO  | GND | 1/4   |
| VIO  | VIO  | GND | 1/8   |
| VIO  | VIO  | VIO | 1/16  |

=== Current Limit ===

Current Limit = Vref x 2.5V/A

=== TMC2208 ===

https://learn.watterott.com/de/silentstepstick/pinconfig/tmc2208/

== Step Mode ==
^ MS1  ^ MS2  ^ Mode  ^
| GND  | VIO  | 1/2   |
| VIO  | GND  | 1/4   |
| GND  | VIO  | 1/8   |
| VIO  | GND  | 1/16  |

== Current Limiting ==
The best way to set the motor current is by measuring the voltage on the Vref pin (0…2.5V) and adjusting the voltage with the potentiometer. The maximum settable motor current is 1.77A RMS (0.11Ohm sense resistors), but the SilentStepSticks can only be used up to 1.2A RMS.

Irms = (Vref * 1.77A) / 2.5V = Vref * 0.71

Vref = (Irms * 2.5V) / 1.77A = Irms * 1.41 = Imax

Vref -> Voltage on Vref pin (Measure on Wiper of Potentiometer)

Irms -> RMS (Root Mean Square) current per phase (Irms = Imax / 1.41)

Imax -> Maximum current per phase (Imax = Irms * 1.41)
==== Rotary Stage ====

* 0.1° minimum resolution
  * AMS AS5147 Magnetic Encoder (On Axis) [[https://ams.com/documents/20143/36005/AS5147U_AS5247U_DS000639_4-00.pdf/1141a423-d438-ff83-df65-0adc533d6801|Datasheet]]
  * Wormgear drive ([[https://www.aliexpress.com/item/4000911615802.html|AliExpress]]
     * 29.5mm Center Distance
     * ~50mm gear diameter

==== Source & Detector ====
  * Distances must be known
     * Source - Center of Rotation (SOD - Source Object Distance)
     * Center of Rotation - Detector (ODD - Object Detector Distance)
     * Source - Detector (SDD - Source Detector Distance)
     *

===== Reconstruction =====

==== Correction ====

Convert x-ray images to projections:

p(s) = -ln(I(s) / I(0))

p(s) : Projected Intensity
I(s) : Intensity recorded at detector after passing through an object
I(0) : Intensity at source (white reference)

==== Filtered Backprojection ====

[[https://tomroelandts.com/articles/tomography-part-1-projections]]

[[https://tomroelandts.com/articles/astra-toolbox-tutorial-reconstruction-from-projection-images-part-1]]

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