1. Temperature Regulation for High-Precision Mass Measurements at ISOLTRAP Elizabeth Wingfield, Florida State, Tallahassee Advisor: Alexander Herlert

2. E. Wingfield August 10, 2006 UM REU Final Presentation Motivation for Precise Mass Measurements Courtesy: A. Herlert Nuclear Physics nuclear binding energies, Q-values shell closures, pairing, deformation, halos, isomers test of nuclear models and formulae  m/m  1·10 -7 Astrophysics nuclear synthesis r- and rp-process  m/m  1·10 -7 Weak Interaction symmetry tests CVC hypothesis  m/m  1·10 -8

3. E. Wingfield August 10, 2006 UM REU Final Presentation ISOLTRAP Setup buncher preparation trap precision trap

4. E. Wingfield August 10, 2006 UM REU Final Presentation Measurement Principles Three independent motions in a penning trap Cyclotron frequency Resonance Spectrum of 85 Rb

5. E. Wingfield August 10, 2006 UM REU Final Presentation ISOLTRAP Measurements Data from: G. Audi et al., Nucl. Phys. A 729 (2003) 3 Masses measured with ISOLTRAP: before 2002 since 2002

6. E. Wingfield August 10, 2006 UM REU Final Presentation Reducing Systematic Error Stabilizing the magnetic field  Pressure of the He recovery line  Center bore temperature Figure: Cyclotron frequencies compared to center bore temperature

7. E. Wingfield August 10, 2006 UM REU Final Presentation Temperature Regulation Setup PID Regulation  Proportional: Controls the gain with respect to the error (error = Set point – process variable) u p = K e(t)  Integral: Looks into the past, the error is integrated over a period of time to reduce oscillations of a P-controlled system u I = K/T i [e i (t-T s ) + T s e(t-T s )]  Derivative: Looks into the “future”, controls the response to a change in a system by measuring the slope of the error u D = KT d /T s [e f (t) - e f (t-T s )]

8. E. Wingfield August 10, 2006 UM REU Final Presentation Prior Temperature Regulation Performance

9. E. Wingfield August 10, 2006 UM REU Final Presentation Current Temperature Regulation Performance P: 400 I: 0.500 D: 2000 Upper limit: 30 W Lower limit: 0W

10. E. Wingfield August 10, 2006 UM REU Final Presentation LabView Update Previous LabView program was re-examined Changes:  Calculation of output value more correctly follows the text-book mathematics  Filter was added to reduce high-frequency noise  A more logical test of the power-range Figure: LabView Block Diagram

11. E. Wingfield August 10, 2006 UM REU Final Presentation Ziegler-Nichols Step Response Method for PID Tuning Applied Power (W)KTiTi TdTd 301304480120 501470480120 701307480120 701486480120 Table: Ziegler-Nichols Step-Response Analysis Didn’t Work!

12. E. Wingfield August 10, 2006 UM REU Final Presentation Many Thanks To: Alexander Herlert and the ISOLTRAP group CERN University of Michigan  Jeremy Herr  Dr. Jean Krisch  Dr. Homer Neal National Science Foundation Ford

13. E. Wingfield August 10, 2006 UM REU Final Presentation Questions?