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Contreras-Martinez, C.

Publications and source records attributed to Contreras-Martinez, C..

17 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Cold Test Results of Pre-Production PIP-II SSR2 Cavities with High-Power Couplers in the Fermilab Spoke Test Cryostat

As part of the PIP-II project at Fermilab, a pre-production cryomodule featuring 325 MHz Single Spoke Resonator type 2 (SSR2) superconducting RF cavities is under construction. These SSR2 cavities are fabricated by industry partners and undergo initial cold testing at our collaborating institution, IJCLab in France, utilizing low-power coupler. Subsequently, the cavities are subjected to final qualification at Fermilab, complete with tuner and high-power coupler assemblies. This paper provides an overview of the ongoing efforts dedicated to high-power testing of jacketed SSR2 cavities in the Spoke Test Cryostat (STC) at Fermilab. Performance parameters obtained from these tests are presented, offering valuable insights into the cavities operational characteristics and readiness for integration into the PIP-II cryomodule.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Cold Test Results of Pre-Production PIP-II SSR2 Cavities with High-Power Coupler in the Fermilab Spoke Test Cryostat

As part of the PIP-II project at Fermilab, a pre-production cryomodule featuring 325 MHz Single Spoke Resonator type 2 (SSR2) superconducting RF cavities is under construction. These SSR2 cavities are fabricated by industry partners and undergo initial cold testing at our collaborating institution, IJCLab in France, utilizing low-power coupler. Subsequently, the cavities are subjected to final qualification at Fermilab, complete with tuner and high-power coupler assemblies. This paper provides an overview of the ongoing efforts dedicated to high-power testing of jacketed SSR2 cavities in the Spoke Test Cryostat (STC) at Fermilab. Performance parameters obtained from these tests are presented, offering valuable insights into the cavities operational characteristics and readiness for integration into the PIP-II cryomodule.

Sukhanov, A.↗
DOE OSTI2024

PIP-II High Beta 650 Prototype Cryomodule Assembly Experience and Related Design Optimization

After shipment to the Daresbury Lab and return to Fermilab, the prototype HB650 cryomodule underwent another phase of 2K RF testing to ascertain any performance issues that may have arisen from the transport of the cryomodule. While measurements taken at room temperature after the conclusion of shipment indicated that there were no negative impacts on cavity alignment, beamline vacuum, or cavity frequency, testing at 2K was required to validate other aspects such as tuner operation, cavity coupling, cryogenic system integrity, and cavity performance. Results of this latest round of limited 2K testing will be presented.

Ozelis, J.↗
DOE OSTI2024

Testing of the SSR2 SRF Cavity Tuner for PIP-II at 2 K

The PIP-II linac will include thirty-five 325 MHz Single Spoke Resonators Type 2 (SSR2) cavities. Each cavity will be equipped with a tuner for resonance control. The tuner consists of mechanical frame with a motor for coarse frequency tuning and a piezoelectric actuator for fine frequency tuning. The tuner was tested for the first time at Fermilab on an SSR2 cavity. This dressed cavity-tuner system was tested at the single spoke testing cryo-stat (STC) in Fermilab at 2 K. The tuner performance was evaluated and is presented. Lastly, cavity-tuner mechanical modes were measured via the piezos.

Contreras-Martinez, C.↗
DOE OSTI2023

Study of Different Piezoelectric Material Stroke Displacement at Different Temperatures Using an SRF Cavity

Piezoelectric actuators are used for resonance control in superconducting linacs. The level of frequency compensation depends on the piezoelectric stroke displacement. In this study, the stroke displacement will be measured with a 1.3 GHz SRF cavity by measuring the frequency shift with respect to the voltage applied. The entire system was submerged in liquid helium. This study characterizes the PZT piezoelectric actuator (P-844K093) and a lithium niobate (P-844B0005) piezoelectric actuator. All these actuators were developed at Physik Instrumente (PI). The piezoelectric displacement was measured at different temperatures.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

PI Loop Resonance Control for Dark Photon Experiment at 2 K Using a 2.6 GHz SRF Cavity

Two 2.6 GHz SRF cavities are being used for a dark photon search at the vertical test stand (VTS) in FNAL, for the second phase of the Dark SRF experiment. During testing at 2 K the cavities experience frequency detuning caused by microphonics and slow frequency drifts. The experiment requires that the two cavities have the same frequency within the cavity's bandwidth. These two cavities are equipped with frequency tuners consisting of three piezo actuators. The piezo actuators are used for fine-fast frequency tuning. A proportional-integral (PI) loop utilizing the three piezos on the emitter was used to stabilize the cavity frequency and match the receiver cavity frequency. The results from this implementation will be discussed. The integration time was also calculated via simulation.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Testing of the 2.6 GHz SRF Cavity Tuner for the Dark Photon Experiment at 2 K

At FNAL two single cell 2.6 GHz SRF cavities are being used to search for dark photons, the experiment can be conducted at 2 K or in a dilution refrigerator. Precise frequency tuning is required for these two cavities so they can be matched in frequency. A cooling capacity constraint on the dilution refrigerator only allows piezo actuators to be part of the design of the 2.6 GHz cavity tuner. The tuner is equipped with three encapsulated piezos that deliver long and short-range frequency tuning. Modifications were implemented on the first tuner design due to the low forces on the piezos caused by the cavity. Three brass rods with Belleville washers were added to the design to increase the overall force on the piezos. The testing results at 2 K are presented with the original design tuner and with the modification.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Simulated Lorentz Force Detuning Compensation With A Double Lever Tuner On A Dressed ILC/1.3 GHZ Cavity At Room Temperature

Pulsed SRF linacs with high accelerating gradients experience large frequency shifts caused by Lorentz force detuning (LFD). A piezoelectric actuator with a resonance control algorithm can maintain the cavity frequency at the nominal level, thus reducing the RF power. This study uses a double lever tuner with a piezoelectric actuator for compensation and another piezoelectric actuator to simulate the effects of the Lorentz force pulse. A double lever tuner has an advantage by increasing the stiffness of the cavity-tuner system, thus reducing the impact of LFD. The tests are conducted at room temperature and with a dressed 1.3 GHz 9-cell cavity.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Tests Of The Extended Range SRF Cavity Tuners For The LCLS-II-HE Project*

The LCLS-II HE superconducting linac can produce multi-energy beams by supporting multiple undulator lines simultaneously. This could be achieved by using the cavity SRF tuner in the off-frequency detune mode. This off-frequency operation method was tested in the verification cryomodule (vCM) and CM 1 at Fermilab at 2 K. In both cases, the tuners achieved a frequency shift of -565$\pm$80 kHz. This study will discuss cavity frequency during each step as it is being assembled in the cryomodule string and finally when it is being tested at 2 K. Tracking the cavity frequency helped enable the tuners to reach this large frequency shift. The specific procedures of tuner setting during assembly will be presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Accelerated Lifetime Test of the SRF Dressed Cavity/Tuner System for LCLS II HE Project

The off-frequency detune method is being considered for application in the LCLS-II-HE superconducting linac to produce multi-energy electron beams for supporting multiple undulator lines simultaneously [1]. Design of the tuner has been changed to deliver roughly 3 times larger frequency tuning range. Working requirements for off-frequency operation (OFO) state that cavities be tuned at least twice a month. This specification requires the in-crease of the tuner longevity by 20 times compared with LCLS-II demands. Accelerated longevity tests of the LCLS-II HE dressed cavity with tuner were conducted at FNAL's HTS. Detail analysis of wearing and impacts on performances of the tuner's piezo and stepper motor actuators will be presented. Additionally, results of longevity testing of the dressed cavity bellow, when cooled down to 2 K and compressed by 2.6 mm for roughly 2000 cycles, will be presented.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗