OCL (Oslo Cyclotron Lab)

Scanditronix MC 35 @ OCL

J. C. Müller OCL for the Cyclotron Workshop 2014 2

OCL Statistics & Achievements

In addition we spend ~200hrs Beam Time on a 11C PET Target installation which led to the succesful production of 11C

in December 2013.

OCL Beam Time Statistic 2013

Beam Proton Deuteron 3He 4He Overall

Hours ~600 ~200 ~280 ~320 ~1400

J. C. Müller OCL for the Cyclotron Workshop 2014 3

Troubles...

● RF Short-Circuit inside Cyclotron

● Anode Power Supply

● Accidently moving of Deflector

● Moisture

J. C. Müller OCL for the Cyclotron Workshop 2014 4

RF Short-Circuit inside Cyclotron

Fault Indication:

● RF would not start

● "Cathode delay" interlock on RF-2 turn off with irregular intervals

● "Air Grid" interlock present, with airflow OK

● Problem tuning RF-1, no reading on U-dee meter on control desk even when attempting pulse start

J. C. Müller OCL for the Cyclotron Workshop 2014 5

RF Short-Circuit inside Cyclotron

What to look for...

Second harmonic problem on RF-1: Seems independent of grid tuning capacitor

RF Detector for RF1 & 2 Anode & Dee Pickoffs RF 1 & 2

J. C. Müller OCL for the Cyclotron Workshop 2014 6

RF Short-Circuit inside Cyclotron

Reason: Grounding Mesh came loose and short-circuited the RF1-Dee

J. C. Müller OCL for the Cyclotron Workshop 2014 7

Anode Power Supply

Fault indication:

● Power supply would not start

● Error indicators

Reason:

● Airflow monitoring circuit broken

J. C. Müller OCL for the Cyclotron Workshop 2014 8

Accidently moving of Deflector

What happened:

● After a Blackout the Main Sond would not move

● Locating the responsible Servo Control Unit

● Accidently activated the Deflector Positioning Servos

● Position readback not plausible

J. C. Müller OCL for the Cyclotron Workshop 2014 9

Accidently moving of Deflector

Reason & Consequnces:

● The Timing Belt connecting the position encoding potmeter with the dc servo motor has disintegrated over time, therefor the Deflector Position was unknown

● Manual repositioning the Deflector with factory settings

● Makeshift solution for replacing the Timing Belt

● New Servo Control Unit (Ongoing Project)

J. C. Müller OCL for the Cyclotron Workshop 2014 10

Moisture

Fault Indication:

● Moisture on all cooled Devices in Summer

Reason:

● Very high humidity and therefor a dew point above the cooling water temperature → Condensation

J. C. Müller OCL for the Cyclotron Workshop 2014 11

Servo Control Unit

● After the Blackout it was decided that the old Servo Amplifier Moduls (SAMs) should be replaced

● 3x 19 inch Rack Units with 11 DC SAMs

● 2x 19 inch Rack Unit for stepper motor control

● Prove of concept for 3x DC Servo and 1x Stepper Motor Controller (Deflector and Sonds) based on NI cRIO

● 2x more Units planed for the remaining 8 DC SAMs

J. C. Müller OCL for the Cyclotron Workshop 2014 12

Servo Control Unit

J. C. Müller OCL for the Cyclotron Workshop 2014 13

OCL...

Thank you for your attention!