# Presentation: 808195

## BCM Update

- Kesselman

## OUTLINE

- Findings/Response to FDR held for HEBT, Ring, RTBT Systems at BNL 7-22-02
- Specs/Preliminaries
- Status
- Over-view of BCM electronics

## FDR (7-22-02) Committee Comments and Responses - 1

***Response:  This is not in the base-line.  It is a requirement for machine protection at low energy and there will be a discussion session on Thursday afternoon.***
**– ****The**** ****Beam Current Monitoring system appears to be in good shape.  Problems with cables and connectors.**
***Response:  Installation procedure implemented by ORNL.***
**– ****The PCI data acquisition card (also used for the BPMs) is not yet finalized.  **
***Response:  Done***
**– ****The calibrate module is not yet finalized.**
***Response:  Bergoz has provided transformer failure mechanisms.  A fused driver is under consideration. More to follow.***

***FDR (7-22-02) Committee Comments and Responses - 1***

## FDR (7-22-02) Committee Comments and Responses - 2

- 

**– ****A bandwidth-limiting filter should be placed in front of the BCM amplifiers to avoid problems caused by out-of-band high frequency signals.**
***Response:  An input capacitor has been added to limit system bandwidth to 100MHz.***
**– ****There is apparently evidence of a 600 to 700 MHz resonance in the BCM shroud.  Consider placing distributed series RC elements across the ceramic gap to shunt high frequency beam image currents.**
***Response:  Noted.  Measurements indicate minor peak and not a concern.  New design reduces volume.  ***

## FDR (7-22-02) Committee Comments and Responses - 3

**– ****The shroud and its connections to the beam tube should be designed and tested to handle SNS 50 amp current.**
***Response: New design uses no “fingers” to carry current and this is no longer a concern (design to be shown later).***
**–****The FPGA should be programmed to not allow nonsense settings.**
***Response: Agree and implemented***

## FDR (7-22-02) Committee Comments and Responses - 4

**– ****Software should verify the integrity and sensibility of measurements, e.g. check for saturation that may result from incorrect gain settings.**
***Response: We will incorporate such software.  Inclusion of the Alterra FPGA will permit appropriate logic to be added to assure correct gain settings.***
**– ****User requirements for beam current monitoring information seem to still be lacking. **
***Response:  Being dealt with at applications level***

## Major Milestones

- DTL – 1st week in May ’03
- Present perception is a 6 week slip
- Ring Hardware – Late Jan ’04
- On schedule

## Schedule

## SNS DESIGN PARAMETERS

- Energy................................1 GeV
- Intensity.............................. 1.5 x 1014 protons
- Repetition Rate.......................60 Hz
- Number of Bunches.................  1
- Injection duration...................  1.0 msec
- Revolution Period.................... 945 nsec
- Bunch Length......................... 695 nsec
- Number of turns...................... 1060

## BCM Requirements

**From SNS Diagnostics AP Requirements (11/05/02)**
- MEBT to HEBT 0.3 - 1000 us,
- 15 to 52mA
- Accuracy < 1% of FSR
- Resolution 0.5% of FSR
- Detail within mini-pulse- available on demand
- Ring to RTBT 5e10 to 2e14 Protons
- 0.015A to 100A
- Accuracy < 1% of FSR
- Resolution 0.5% of FSR
- Turn-by-turn data- available on demand
- Interpretation of requirements

## Beam Current Monitor Distribution

## System Electronics Configuration

- XFMR

- AFE

- 40 MHz/68MHz LO

- GAIN

- DAC’s & ADC’s

- DFE

- PCI DAQ

- TIMING MODULE

- CLK

- 16 MHz Reference

- Event Link

- RTDL

- RACK MOUNT PC

- PCI   BUSS

- CONTROL

- LabVIEW

- CONTROL
- SYSTEM

- XFMR

- Memory
- or
- FIFOs

- CAL

## System Status

- A Prototype system has been delivered to LBNL and then upgraded (rev C) and delivered to ORNL.  This system failed during commissioning at ORNL (due to unexplained over-voltage) and was repaired.  It is presently operating at ORNL.
- Three (3) additional rev C - BCM systems are in process for delivery in April to support Linac commissioning. We have two LANL PCI cards and are building some more.
- To replace two parts that have been made obsolete by the manufacture, requires another art-work revision.  Our plan is to leave the connectors at board end but assure they stay within the PCI board spec and incorporate minimal artwork changes (present design works).
- HEBT BCM design is complete. Final drawings are in preparation.  Ring, and RTBT BCM design is underway.
- Calibrator design for the Ring and RTBT is in progress.

## Elog 1-29-03 ORNL MEBT CommissioningSource Delay Mode

## HEBT, Ring, RTBT Current Transformers

## HEBT BCM ASSEMBLY

**HEBT BCM ASSEMBLY**

## COMPONENTS INSIDE HEBT BCM ASSEMBLY 

**COMPONENTS INSIDE HEBT BCM ASSEMBLY**

## PRELIMINARY RING/RTBT BCM DESIGN

**PRELIMINARY RING/RTBT BCM DESIGN**

## 250 us MEBT Pulse – During Berkeley Commisssioning

## Process Variables (2 Channels) -1

- Chart Data :
- Current chart – comfort display (<256 elements)
- Averaged over specified time
- Variables
- Delay time
- Time to display
- Particle count chart– (integral of current waveshape)
- Particle count, averaged over the entire macro-pulse
- Particle count, holding average over each mini-pulse (particles)
- array holding raw data for macro-pulse

## Process Variables (2 Channels) -2

- Additional PVs
- Sampling Frequency
- Gain setting – tied to data points
- Initialize Hardware Control –True/False(auto reset)
- PCI Card number
- Delay time from trigger
- Number of points to store
- FIFO Selection
- Update graphs control ON/OFF
- Calibration current value
- Conversion gain
- Current calibration value
- Control to permit calibration analysis ON/OFF
- Delay time
- Calculation time
- Droop computation
- Transformer time constant
- DC Offset value
- DC Offset calculation delay time
- DC Offset calculation time
- Control to permit droop analysis ON/OFF
- Droop Calculation - Delay time
- Droop Calculation - Calculation time

## Calibrator Purpose and Requirements

-   Calibrator Purpose
- 	Provide a dynamic, on-line measurement of FCT droop time constant
- 	Confirm the gain of the BCM at various settings
-   MEBT, DTL, CCL, SRF and HEBT (16 Transformers)
- 	**One range for BCM  (0-100 ma) **
**	****calibration current from 12 bit DAC (up to 20ma)**
-   Ring and RTBT (6 Transformers)
- 	_**Will Add **_** 3 BCM ranges.   High current driver required (up to 4 amp)**
**	****	****350 ma full scale  (35 ma from calibrator)**
**	****	****4.2 Amps full scale  (420 ma from calibrator)**
**	****	****50 Amps full scale   (4 Amps from calibrator)**
**	****High current driver has a rise time of 1.6 usec, too long for good amplitude meas.**
**	****Plan on two calibration pulse shapes, pulse for droop, sine wave for gain**
- Transformer Protection
- 	**Driver outputs fused to protect from fault currents**
**	****Limited Current from Driver Power Supplies **

## BCM Calibrator Block Diagram

- Optical Isolators

- Data/Address
- 12 Bits

- Timing/
- Control

- Memory
- 64kb/167Mhz

- 12 Bit DAC
- 125Msps

- Timing / Control
- Logic

- Differential
- Driver

- 0-10ma

- To calibration
- Winding (alt.)
- 0-2 Amp

- To Calibration
- Winding

- Shows one of two channels

## Design Features

-   Basic Design Features
**	****A Function Generator using a 12 Bit DAC and a 64kb memory**
**	****Two output ports**
**	****	****DAC output directly drives lowest current range**
**	****	****Current driver drives all other ranges ( 350ma to 50 Amp)**
**	****Isolation from local ground provided by opto-isolators and DC/DC converter**
**	****	**
-  Transformer Protection
- 	**Driver outputs fused to protect from fault currents**
**	****Limited Current from Driver Power Supplies **
-   Packaging
- 	**On a multi-layer pcb inside the pc chassis drive bay**

## Back-up

## Xfer response through New 8 Inch BCM Fixture

## Xfer function to Xfmr Out of new 8 Inch BCM

## S22 Measurement – New 8 Inch BCM Test Apparatus