Status of EPICs Operations

1. Status of EPICs Operations Pedro Calderón Riaño Guillermo Buenadicha MALLORCA 05/11/2007

2. Contents Status of operations since Palermo Pedro Calderon Future activities and open points Guillermo Buenadicha

3. Overview • Smooth operations, in general • MOS2 +32 Volts line drop • New hot stuff, 3X3, CCD6 check • New MOS CCD thermal control • Future procedure changes

4. Routine Operations • RBI clock resync every ~194 days • Last on May 29th, next on December 10th • Eclipse season fully nominal. • All performed automatically by timeline. • A MOS-2 exp in Full Frame 2 Nodes mode • The exposure was erroneously planed. This mode is not commissioned. • A TC failed during the reconfiguration after the end of the exposure. The activity has a flaw at that point -> to be corrected.

5. MOS2 +32V drop • The voltage in the +32V line drop instantaneously to 0 volts in the middle of a normal observation, the CCD stop generating events, and no other telemetry parameter showed any change or spike. • After a switch OFF / switch ON the instrument returned to full nominal. • Happened a similar incident in MOS-1 on 2002 (NCR#105), but never again. • MRB with Saclay, Leicester and ESAC • Suspected a SEU in EMVC electronic ??

6. New Hot Stuff • New versions of the MOS Offset Tables • Now at version V12 • New versions of the PN Bad Pixel Tables • Fixed the bright 64 column in CCD 11 • Changes in place since Rev 1389 (July 11th) but they were not in full use until Rev 1408 (August 16th)

7. MOS 3x3 pointed obs • Mode tested on March 30th • Real observation performed in May 2nd on PSR B0833-45 (rev 1354, OBS_ID 0510390101, routine calibration obs) • Operations OK

8. New ED for CCD6 checks • New ED now available • Last check performed on October 29th using the new ED • The operation was quick and easy • No changes in results (still full of AFFA hex events)!!!

9. CCD6 image

10. New MOS CDD thermal control • Exist only 1 circuit (plus redundant) for the 3 cameras CCD substitution heaters. If heater are ON for one camera, they are ON for all. • If a camera has problems, all cameras are heated => bad science • The new idea : avoid heating the CCD of the cameras that are still working

11. New MOS CDD thermal control • How to do that? • Allowing the unpowered CCD to cold down to the minimum tested temperature (-140 degC). • That is near to the external radiator temp, so a lot of time is needed. • Then trigger heaters ON up to operational temperature, and switch OFF again • Heaters will be ON for limited time, so the impact in the other cameras is reduced • All this is done via manual procedure

12. New MOS CDD thermal control

13. Future actions • Change of procedures to recover PN from Safe Standby • Now PN never goes normally to SSB, but the procedure should be up to date any way • The idea is switch off all PN, switch on the substitution heaters, and when all temperatures are good (remember the problem with the currents when the EPVC is cold, NCR#90), do a full switch on.

14. Future activities & open issues • MOS redundant node readout • MOS and PN, comparison of timing flux • Rev 1325 Crab timing • Periodic CCD-6 health check • PN activities foreseen • Slew survey • S2K support

15. MOS redundant node readout • Action pending since TTD@MPE, May 2006 • The rationale is twofold: • Assess the capability to react against a HW failure in MOS (similar to RGS-2 case) • Gain expertise at ESAC building MOS sequences • Sequences currently in DB? Too many… • All delivered sequences were kept since launch (and even since FM) • Naming convention has never been consistent • Not all of them used In Flight • However, there are some sequences capable of reverse clocking  tests in April 2005, MOS-1 CCD-6

16. MOS redundant node readout • How to proceed? • When • It is a task not too urgent, but desirable to be done before T. Abbey runs away • If current DB sequences are able to do the job, then the design part is not an issue • Do we aim for Spring 2008? • Who • Ideally engineers at ESAC and T. Abbey + TBD replacement? • How • Either developing new sequences from scratch, or using the DB ones, followed by tests at the Spare and/or on the real unit. • Last step would be the creation of the DB items (ED’s) to cope with eventual node failure.

17. Timing events PN/M1/M2 • Project started by M. Kirsch and John Olaffson (trainee at ESAC). • The idea is to analyze and compare the normalized flux in timing observations among EPIC cameras • Study is still ongoing, some preliminary cases required some support to understand deviations from a nominal ratio • Cases in which MOS-1 deviates (above) from MOS-2 and PN (possible influence of MOS-1 hot column under weak sources) • Cases in which both MOS deviate (below) from PN, all in counting. Analysis is required to assess influence of MOS CCD stuck mechanism and the SAS processing of GTI. • Screening of data is ongoing, also the Long Term Archive for HK analysis is being populated.

18. 1325 Crab timing… • M. Kirsch reported a 600 microseconds absolute time deviation in the Crab observation in rev 1325. • Nothing abnormal detected in ODF Timing files and no G/S problem found. • A TCS generation problem after the given epoch was found at MOC due to old Orbit products. • However, TCS vs. TCX analysis seems OK, shows TCX is independent on the MOC orbit file. • Mission long TCS vs. TCX analysis is required just to find different behaviors among files. • TCX is available and in use for timing observations through SAS.

19. Periodic CCD-6 health check • Past operations • Tests in April 2005 after CCD failure • TTD in MPE May 2006 recommended periodic switch on • Done twice in 2007 (March and October) without success… • Is it still worth it? • It is not really time consuming at MOC or SOC, since now is almost fully automatic. • Can we link this activity to some periodic calibration or diagnostic for MOS? • Helps programming the activity regularly

20. PN activities foreseen • Past non routine operations since Palermo • Minimal (not to say none!!!) • Situation seems very stable for the instrument • Any idea or suggestion to: • Improve operations? • Exercise operations under failure cases?

21. Slew survey, are we done through • Past operations • Already reported by Pedro, real target in May. • Future activities and open points • Offset maps required?  current ones are still theoretical • Calibration items?  What would be the calibration efforts and type of tests? • Others?

22. S2K in Spare support • Support in the validation of the S2K once it is integrated in the Spare chain. • Adaptation of DB items to spare (offsets, BP’s, clocks, voltage settings). • Define a mirroring mechanism to upgrade Spare DB in line with future operational concepts.