Oliver Bitterling

 Introduction to the QPS  Radiation damage in electronic systems  Construction of radiation tolerant systems  Radiation test and their results  Conclusion and outlook

 Detection of loss of the superconductivity of the LHC Magnets  Loss of local superconductivity is called a Quench  Undiscovered Quenches lead to serious damage to the accelerator  Discovered Quenches can be mitigated without damage

 The increase of availability is an important goal of the redesign of the QPS  QPS must not overlook any quenches but should only produces as few as possible false triggers  QPS is located close to the accelerator and is subjected to certain amounts of stray radiation  Radiation can cause damage and random errors inside electronic systems

 High doses of high energy radiation can destroy semiconductor lattice  Even low doses can cause statistical radiation errors

 Two high resolution ADCs are necessary to measure the current and voltage with the necessary precision

 Some components are specially constructed in a way that makes them highly resistant to radiation  Such hardware is usually used for space applications like satellites Problems: Very Expensive!!! Not available

 “Components of the shelf” (COTs) differ widely in their resistance to radiation  COTs have to be tested a irradiation facilities to determine how the react to radiation  The ADC for our project was tested at the Paul-Scherrer-Institute (PSI)  A future radiation test will be conducted at the new irradiation facility CHARM at CERN

 Typical voltage and current during a magnet ramp as stimulus  ADC survives even after high doses of radiation  Output signal is corrupted

 Typical irradiation level of 1 Gy every year (later 10 Gy)  System consists out of 200 cards with two ADCs  Resulting error rate of 1 error every 3 days

 After countermeasures error rate decreases to 1 error every year  Final version should be able to eliminate all errors

 The QPS has to be very precise to prevent damage and increase beam time  Radiation can disturb the operation of the QPS and lead to premature beam dumps  Using tolerant hardware and error specific countermeasures it is possible to develop systems able to work under radiation  Latest measurements have shown that the system is already sufficiently stable but there are still ways to improve

 Disturbances in the signal can be mitigated by using a combination of several digital filters  Normal ADC stops can be tolerated by the system  Longer stops could be prevented by automatic restart of the ADC  Configuration errors can be fixed by continuous monitoring of the configuration register and fixing any errors

 FPGAs that store their configuration inside SRAM cells are highly vulnerable to radiation effects  A possible method to allow them to function is to constantly read out the configuration, check for corruption and fix as necessary  Flash based FPGAs are more tolerant to radiation

 Triplication protects the algorithm by creating 3 instances of every part  If only one part is corrupted a majority vote will only transmit the correct result