1. GMPS Transductor Upgrades And Realtime B Field Measurement for Reference Magnet Xiaolong Zhang, Kent Triplett, Jeff Larson

2. History of Ref.Mag. Transductor The transductor measures the GMPS excitation current and thus plays a role in regulation of B:IMAX and B:IMIN. Original Main Ring transductors were 7500A 2mV per Amp-Turn with 5Ω burden resistor – design by Q. Kerns (0435.06-EE-45928). Our transductor came from that design w/ some circuit modifications including a 20Ω burden resistor. It appears this is an 1875A unit, 8mV per Amp-Turn, DC to 300kHz.

3. History of Ref.Mag. Transductor There is some documentation about a 1200A GMPS transductor (0323-ED-36916) from 1974. However, the unit we have in service appears to match the 1875A model. We have a back up spare transductor electronics unit. Physically, it appears to be in good shape, but we have not powered it, and don’t know if it is a viable spare. There is no spare head for our transductor. John Reid may have some relevant parts at MI60 somewhere, but these have not been located.

4. Reference Magnet Transductor Head LocationProposed Location New Transductor Head

5. Transductor Head Located in the Reference Magnet Box

6. Bus Connection to Transductor Head Proposed location for new transductor head mounting

7. Now via VXI & Transductor + BDOT Buffer + Zero Crossing Detector

8. Proposed Upgrades There are a few commercial current transformer readily available with modern electronics from Hitec, Danfysik/LEM and ZES. Their specification (0 - 50KHz):  Accuracy: < 3 ppm  Output noise: < 6 ppm Advantage of the upgrade:  Improve the accuracy of the GMPS current monitoring.  Better for the feedback/feedforward system.

9. Pros: $5575/unit. Used in the lab at beam line. Cons: 4-6 weeks delievery From HITEC

10. PSU1000HF: $2615 each. This requires +/- 15 V power supply. If connecting to one of our power analyzers, we have cables made to provide this supply. SAT2000: $7699.00 each. Includes transducer head, power supply and cabling up to 30m. Both are in stock in up to 10 pcs. From ZES Zimmer Precision Power Measurement

11. Specifications - ITP Current Transducers Electrical ModelSymbol ITP 2000-SPR ITP 2000-S/SP1 ITP 2000- SBPR Units Former Danfysik Model STH-2000ISTH-2000IHFSTH-2000U PolarityBipolar Secondary Nominal CurrentI sn ±1±2- A Nominal voltage output Max. output load current Max. output load cap. V on I o,max C o,max -- ±10 5 3 V mA nF Ext. burden resistor max Ext. burden resistor min R b,max R b,min 1.5 0 -Ω Transfer ratio (I p /I s ) N 20001000- - Transfer ratio (I p /V s ) G - 200A/V Max nondestructive overload Min overload trip value I p,max I p,min 5x 1.3x I pn Offset - Initial - Drift vs. Temp. - Drift vs. Time -<2 <0.1 <1 <2 <0.6 <1 ppm ppm/°C ppm/month Transfer ratio - Deviation - Deviation vs. Temp. - Deviation vs. Time - <4 <0.1 <1 <50 <2 <2 ppm ppm/°C ppm/month Linearity Deviation Linearity Deviation vs. Temp. X d X d,temp <2 <0.1 <4 - ppm ppm/°C Output noise rms- <0.01 <3.5 <5.5 <0.01 <3 <5.5 <0.15 <5.5 <16 ppm,rms ppm,rms ppm,rms Dynamic resp. slew rate Dynamic resp. delay time dl/dt t d >20 <1TBD A/µS µS Bandwidth ±3dBf0-500-3000-50kHz From LEM Danfysik

12. Quote for Danfysik

13. Realtime B Field Monitoring By measuring the B field during the cycle and comparing to the excitation curve, it supply us with another reference for the transductor. It’ll give us another instrument for B-dot timing system reference. The available commercial product of Lakeshore Gaussmeter will be a good option. (Much more benefits if it were a spare gradient magnet.)

14. Reference Magnet BDOT Coil

15. Lakeshore 455 Single Channel

16. Benefits of These Upgrades We could measure the real time B field. Build a better GMPS feedback/feedforward system. Improve the B-dot timing system to better synchronize the beam transfer and other beam diagnosing.

17. Backup Slides

18. Transductor & BDOT Buffer & Zero Crossing Detector

19. Proposed location for new transductor head mounting

21. Specifications of Lakeshore 460 ProductPriceTotal Gaussmeter, 460,$5,975.00 Two-axis probe: 8 in long $1,537.00 Probe, metal transverse, 0.06 x 0.18 x 8 in $598.00