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Pischalnikov, Y. M.

Paper Title Page
WEPMN094 Experience with Capture Cavity II 2251
  • T. W. Koeth, J. Branlard, H. Edwards, R. P. Fliller, E. R. Harms, A. Hocker, T. W. Koeth, M. McGee, Y. M. Pischalnikov, P. S. Prieto, J. Reid
    Fermilab, Batavia, Illinois
  Funding: This work supported by Universities Research Association Inc. under contract DE-AC02-76CH00300 with the U. S. DOE.

Valuable experience in operating and maintaining superconducting RF cavities in a horizontal test module has been gained with Capture Cavity II. We report on all facets of our experience to date.

WEPMN103 Mechanical Stability Study of Capture Cavity II at Fermilab 2274
  • M. McGee, Y. M. Pischalnikov
    Fermilab, Batavia, Illinois
  Problematic resonant conditions at both 18 Hz and 180 Hz were encountered and identified early during the commissioning of Capture Cavity II (CC2) at Fermilab. CC2 consists of an external vacuum vessel and a superconducting high gradient (close to 25 MV/m) 9-cell 1.3 GHz niobium cavity, transported from DESY for use in the A0 Photoinjector at Fermilab. An ANSYS modal finite element analysis (FEA) was performed in order to isolate the source of the resonance and directed the effort towards stabilization. A novel idea was implemented, by using a fast piezoelectric tuner to excite (or shake) the cavity at different frequencies (from 10 Hz to 200 Hz) as a low-range sweep for analysis purposes. Both warm (300 K) and cold (1.8 K) accelerometer measurements at the cavity were taken as the resonant 'fix' was applied. FEA results, cultural and technical noise investigation, and stabilization techniques are discussed.

Operated by Universities Research Association, Inc., under Contract No. DE-AC02-76CH03000 with the U. S. Department of Energy#mcgee@fnal.gov

WEPMN105 Fast Thermometry for Superconducting RF Cavity Testing 2280
  • D. F. Orris, L. Bellantoni, R. H. Carcagno, H. Edwards, E. R. Harms, T. N. Khabiboulline, S. Kotelnikov, A. Makulski, R. Nehring, Y. M. Pischalnikov
    Fermilab, Batavia, Illinois
  Funding: Work supported by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.

Fast readout of strategically placed low heat capacity thermometry can provide valuable information of Superconducting RF (SRF) cavity performance. Such a system has proven very effective for the development and testing of new cavity designs. Recently, several RTDs were installed in key regions of interest on a new 9 cell 3.9 GHz SRF cavity with integrated HOM design at FNAL. A data acquisition system was developed to read out these sensors with enough time and temperature resolution to measure temperature changes on the cavity due to heat generated from multipacting or quenching within power pulses. The design and performance of this fast thermometry system will be discussed along with results from tests of the 9 cell 3.9GHz SRF cavity.

WEPMN108 A Technique for Monitoring Fast Tuner Piezoactuator Preload Forces for Superconducting RF Cavities 2289
  • Y. M. Pischalnikov, J. Branlard, R. H. Carcagno, B. Chase, H. Edwards, A. Makulski, M. McGee, R. Nehring, D. F. Orris, V. Poloubotko, C. Sylvester, S. Tariq
    Fermilab, Batavia, Illinois
  Funding: Work supported by Universities Research Association Inc. under Contract No. DE-AC02-76CH03000 with the United States Department of Energy.

The technology for mechanically compensating Lorentz Force detuning in superconducting RF cavities has already been developed at DESY. One technique is based on commercial piezoelectric actuators and was successfully demonstrated on TESLA cavities*. Piezo actuators for fast tuners can operate in a frequency range up to several kHz; however, it is very important to maintain a constant preload force on the piezo stack in the range of 10 to 50% of its specified blocking force. Determining the preload force during cooldown, warm-up, or re-tuning of the cavity is difficult without instrumentation, and exceeding the specified range can permanently damage the piezo stack. A technique based on strain gauge technology for superconducting magnets has been applied to fast tuners for monitoring the preload on the piezoelectric assembly. This paper will address the design and testing of piezo actuator preload sensor technology. Results from measurements of preload sensors installed on the tuner of the DESY Capture Cavity II tested at Fermilab will be presented. These results include measurements during cooldown, warm-up, and cavity tuning along with dynamic Lorentz force compensation.

* M. Liepe et al," Dynamic Lorentz Force Compensation with a Fast Piezoelectric Tuner" PAC2001

MOPAS023 Nb3Sn Accelerator Magnet Technology R&D at Fermilab 482
  • A. V. Zlobin, G. Ambrosio, N. Andreev, E. Barzi, R. Bossert, R. H. Carcagno, G. Chlachidze, J. DiMarco, SF. Feher, V. Kashikhin, V. S. Kashikhin, M. J. Lamm, A. Nobrega, I. Novitski, D. F. Orris, Y. M. Pischalnikov, P. Schlabach, C. Sylvester, M. Tartaglia, J. C. Tompkins, D. Turrioni, G. Velev, R. Yamada
    Fermilab, Batavia, Illinois
  Funding: This work was supported by the U. S. Department of Energy

Accelerator magnets based on Nb3Sn superconductor advances magnet operation fields above 10T and increases the coil temperature margin. Development of a new accelerator magnet technology includes the demonstration of main magnet parameters (maximum field, quench performance, field quality, etc.) and their reproducibility using short models, and then the demonstration of technology scale up using long coils. Fermilab is working on the development of Nb3Sn accelerator magnets using shell-type dipole coils and react-and-wind method. As a part of the first phase of technology development Fermilab built and tested six 1-m long dipole models and several dipole mirror configurations. The last three dipoles and two mirrors reached their design fields of 10-11 T. Reproducibility of magnet field quality was demonstrated by all six short models. The technology scale up phase has started by building 2m and 4m dipole coils and testing them in a mirror configuration. This effort complements the Nb3Sn scale up work being performed in the framework of US LHC Accelerator Research Program (LARP). The status and main results of the Nb3Sn accelerator magnet development at Fermilab are reported.

WEPMN092 Capture Cavity II Results at FNAL 2245
  • J. Branlard, G. I. Cancelo, R. H. Carcagno, B. Chase, H. Edwards, R. P. Fliller, B. M. Hanna, E. R. Harms, A. Hocker, T. W. Koeth, M. J. Kucera, A. Makulski, U. Mavric, M. McGee, A. H. Paytyan, Y. M. Pischalnikov, P. S. Prieto, R. Rechenmacher, J. Reid, K. R. Treptow, N. G. Wilcer, T. J. Zmuda
    Fermilab, Batavia, Illinois
  Funding: FRA

As part of the research and development towards the International Linear Collider (ILC), several test facilities have been developed at Fermilab. This paper presents the latest LLRF results obtained with Capture Cavity II at these test facilities. The main focus will be on controls and RF operations using the SIMCON based LLRF system. Details about hardware upgrades and overall system performance will be also explained. Finally, design considerations and objectives for the future test facility at the New Muon Laboratory (NML) will be presented.