1 / 1

Inertial Sensor Development for a 1 TeV Linear Collider

cade-mcfadden
Download Presentation

Inertial Sensor Development for a 1 TeV Linear Collider

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The proposed 1 TeV X-band electron / positron linear collider will produce beams with approximately 1 nanometer vertical sizes at the collision point. The final focusing magnets for this accelerator must be held relative to each other at the nanometer level. Beam – Beam interactions provide a signal for a high gain feedback for frequencies below ~1Hz, but additional stabilization is required at higher frequencies. One option is to use inertial sensors (geophones) to provide a feedback signal. Inertial Sensor Development for a 1 TeV Linear Collider Requirements Noise: < 1 nanometer integrated above 1Hz. Frequency response: 0.1Hz to 50Hz. Must operate in 1 Tesla magnetic field Compact - ~20×20×10 cm Technology: RF capacitive position sensing Position feedback through DSP Feedback force -> measured acceleration BeCu spring, Ceramic moving parts Prototype sensor Parameters Test mass 40 grams Suspension frequency 1.5Hz Mechanical Q >100 Theoretical thermal mechanical noise <1.5×10-10M/s2/Hz1/2. Capacitor Sensor gap ~300 microns Theoretical thermal electronic noise < thermal noise Vacuum <few microns Eric Doyle, Josef Frisch, Linda Hendrickson, Thomas Himel, Thomas Markieweicz, Justin May, Richard Partridge, Andrei Seryi Work Supported by Department of Energy Contract DE-AC03-76SF0515 Technical Issues: Creep Spring must be operated at high stress to maximize unwanted 2nd mode frequency (from ANSYS simulations) Lifetime of sensor limited by creep of spring. Tests at design 75% of yield stress give creep life >20 years. Creep chart Technical Issues: Magnetic sensitivity Housing, fixed supports: Non-magnetic stainless, Aluminum Motor: (for creep / temperature compensation) Piezoelectric motor (PicomotorTM), nonmagnetic in final system Cantilever: Prototype uses Aluminum cantilever. (conductor: dB/dt problem) Final version uses Aluminum Oxide cantilever Mass: Tungsten in prototype (magnetic in first prototype!) Final version: HfO2 9.8g/cc, (heaviest non-radioactive ceramic) Technical Issues: Creak High spring stress can produce creak Also ,early prototype had problems with creak in support components (support position pot) Technical Issues: Temperature Sensitivity Non-magnetic requirement prevents the use of temperature compensated spring materials. Calculated temperature sensitivity ~.01 M/s2 / °C, 10 nano-degree temperature variation (during measurement time) would limit resolution. Design incorporates multiple thermal filters, gold plating for radiation shielding. Temperature variations probably major noise source below 0.1Hz. Preliminary Data – not verified! Initial testing of sensor vs. Strekheisen STS-2. Testing done in noisy lab environment: high Frequency noise (5-100Hz) exceeds sensor feedback actuator strength. Noise floor <~10-8m/s2/sqrt(Hz) Noise 1/f corner ~0.1Hz. Future Work: Test in quiet location Install fully non-magnetic components Try reduced spring stress to reduce creak. Add temperature stabilization

More Related