# Presentation: 235597

## Beam Loss Monitor Upgrade

**J. Lewis**
**Controls Group Meeting**
**14 September 2004**

## Motivation

**Don’t do this again.**

**Loss profile: Roman-pot 16-house quench**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Existing System Characteristics and Limitations

**Signal properties**
**Good resolution and dynamic range**
**Fast leading edge response, slow discharge**
**Tevatron Aborts**
**Fast:  ~ 50-100 μs**
**Fires on single channel over threshold**
**Minimal compatibility with multiple machine configurations**
- Two abort levels, high and low field
- Not allowed to Abort when pbars are in the machine
**Read out **
**Via the old BPM system using the External Device Bus**
- The BPM is dead.  Long live the BPM
- New system commissioned by March 2005
**Updates slowly: ~ 3 ms period**
**Difficult to enhance and maintain**
**23 years old**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Requirements for New System

**Robustness:  No false aborts**
**Reliability:   No missed aborts**
**Respond to changing machine configurations**
**Change abort channel-by-channel abort thresholds and masks in response to **_**TCLK or MDAT events**_
**Maintain resolution**
**System designed around low-noise integrator**
**Good time resolution and depth**
**Multiple integration periods, each with >4k sample history**
**Also work for MI and Booster**
**Accelerator activation due to beam losses limits increased intensity**
**Include experiments in Tevatron BLM system**
**Two camac crates with special electronics hard to maintain**

- BLM Upgrade -- J. Lewis

- 9/14/04

## System Overview

**Integrate BLM current and digitize at Tevatron  turn frequency**
**Form three running sums for additional  integration periods**
**Programmable time constants**
**One abort threshold per integration period for each channel**
**Abort thresholds and masks changed in response to machine states **
**Embedded microprocessor**
**Custom local bus on J2 **
- Isolated from VME and Ethernet

- BLM Upgrade -- J. Lewis

- 9/14/04

## Components

**Digitizer**
**4 channels with integrator and ADC**
**Generates primary abort signals**
**Timing Card**
**Synchronizes digitizers**
**Latches control signals**
**Abort Concentrator**
**Masking and multiplicity of inputs from digitizer**
**Controller**
**Interface to VME for crates with abort**
**High Voltage**
**Front-End CPU**
**MVME 2xxx: Acnet interface, etc.**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Digitizer

**4 Loss Monitor Channels**
**Dual Charge Integrator (Burr Brown ACF2101)**
- Alternately integrating or being readout and reset
- Provides continuous measurement
- 50 kHz maximum sample rate
**16-Bit SAR ADC**
**DAC to give analog scope output**
**FPGA**
**Controls integrators**
**Reads ADCs**
**Stores readings (raw measurements)**
**Forms three running sums**
- Example: 1ms, 10ms, 1s periods
**Compares readings and sums to programmed thresholds **
- Results sent to Abort Concentrator
**512 kByte RAM to store 64k raw data in circular buffer**
**Maximum 16 cards per crate**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Timing Card

**Provides synchronous integration clock to digitizers**
**External input (e.g. Tevatron AA marker)**
- Can also be divided (e.g. AA2 for MI)
**Internal oscillator**
**Time stamp buffer in sync with the digitizers’ 64k data buffers **
- Time stamp raw measurement data
**TCLK decoder to receive clock events**
**Real Time Clock for Data Tagging **
**Set via I/O from Host**
**32-bit microsecond counter **
**Reference to TCLK reset events**
**Fine time stamp**
**Synchronize with BPM**
**Keeps time for sampled measurements (Snap Shot Buffers)**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Abort Concentrator

**FPGA receives abort info from the digitizer cards, compares against abort masks and multiplicities and makes the abort signals**
**One abort input for each time-range from each channel**
- Maximum 32 channels per crate participate in abort
**Separate decisions for each time-range**
- Independent masks and multiplicities
- Ranges can be redundant
**Aborts are formed in < 20 microseconds**
**TTL Abort signals driven off on 50 ohm cables**
**One for each of 4 ranges**
**One global OR**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Controller Card

**Communicates with other cards on control bus**
**Bus master**
**Includes MDAT receiver to get machine state changes**
**Isolates Abort functions from outside world**
**FPGA VME slave and control-bus eZ80 access shared memory**
- Circular buffers for running-sum data (snapshots)
- Stores BLM thresholds and abort requirements for each machine state
**Loads parameters into digitizer and abort concentrator cards based on machine state**
**Maintains “Flash”, “Profile”,  and “Display” frame buffers (response to TCLK)**

- BLM Upgrade -- J. Lewis

- 9/14/04

## High Voltage

**1 or 4 channels depending on location**
**Voltages set via VME**
**Includes readback of return voltage from BLM daisy chain**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Chassis

**Weiner 6U VME crate**
**Low-noise power supply**
- 15mV p-p on 5V
**Excellent track-record**
**Housekeeping readout via Ethernet**
- Fans, voltages, temperatures, remote VME reset

- BLM Upgrade -- J. Lewis

- 9/14/04

## Front End CPU

**Tevatron**
**Want to recycle MVME2301 from CDF**
**30 available by 2005 shutdown**
- Need 27 plus spares
**Objections???**
**MI and Booster**
**Buy MVME 2434-1**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Software

**Programs Using Tevatron BLM Data (B. Hendricks 9/03)  **
**PA0384 (D40  )**** - Hardware diagnostics (rewrite) **
**PA0506 (T38  )**** - Ringwide hardware tests and status readbacks (rewrite)  **
**PA0422 (T40  )**** - General display program (BLM display) (rewrite)**
**PA1048 (T39  )**** - General display program (flash, display, snapshot, profile)  **
**PA0272 (T44  )**** - BLM time plot (rewrite)**
**PA1670 (T117)**** - Orbit closure (flashes and displays)**
**PA1753 (C50  )**** - Tevatron orbit program (snapshots and profiles)**
**PA0769 (C116)**** - Orbit program (old) (snapshots and profiles) (obsolete?)**
**PA1551 (W10 )**** - Orbit program (old) (snapshots and profiles) (obsolete?)**
**PA1585 (W62 )**** - Collider luminosity calculation (snapshots) (obsolete?)**
**PA1981 (W132)****- BPM library test program  **
**UL_CBSAUX****   - BPMUTI (BPM support library)**
**TEVCAL         **** - Tevatron calculation OAC (saves snapshots in file)**
**Also need store totals for experiments (JDL)**
**Need comparable lists for Main Injector and Booster**
**Front-end code is all new**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Proposed Machine States

**Tevatron Operation**
**Proton Studies (i.e. uncoalesced batch at 150)**
**Proton Injection**
**Activate Separators**
**Pbar Injection**
**Ramp**
**Squeeze**
**Scraping**
**HEP**

**F Sector (change mask) **
**P2 Beam**
**P2 & P3 Beam**
**F-Sector Restore**
**Experiments **
**CDF Silicon Biased**
**CDF Silicon Off**
**D0 Silicon Biased**
**D0 Silicon Off**

- What’s missing?

- BLM Upgrade -- J. Lewis

- 9/14/04

## Personnel

**Alan Baumbaugh  (PPD/EED)**
**System design, Controller card**
**Kelly Knickerbocker  (PPD/EED)**
**Timing card, infrastructure**
**Craig Drennan  (AD/BS)**
**Digitizer**
**Marvin Olson (AD/ID) **
**System support**
**Cecil Needles (PPD/EED)**
**Digitizer Firmware**
**Mike Utes (PPD/EED)**
**Abort Concentrator**

**Jonathan Lewis (PPD/CDF)**
**Management**
**Stephen Pordes  (AD/ID)**
**Wisdom and advice (solicited or otherwise)**
**Alberto Marchionni  (AD/MID)**
**MI contact**
**Brian Fellenz**
**HV card (just starting)**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Schedule

**Digitizer prototype in hand**
**Full-crate test Feb. 2005**
**Will need to devote BLMs from one house to new system**
**Develop and test software**
**Get operational experience**
**Install crates when old BPM electronics removed**
**Get host CPUs running ASAP**
**Install modules as available**
**Exercise (nearly) complete system in summer 2005**
**Move BLM cables to new system in 2005 Shutdown**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Experience

**Studies with 2-channel digitizer test card**
**Understand signals and noise**
**Selected sites in Tevatron, MI and Booster**
**Check calibration for Tevatron**
**Old system:  50nA ↔ 0.84 Rad/s**
**New system: 50nA ↔ 56 counts (20μs bins)**
**Explored noise suppression**
**Wide channel-to-channel variation variation**
**Filters**
- Chokes for common mode
- Resistor to increase effective integration time
**Running sums**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Booster: LM23

- 1ms/div

- ~1pC/div
- (per 20μs)

- Raw

- Choke

- Choke+25k

**720 Hz**
**noise**

**Signal**

- BLM Upgrade -- J. Lewis

- 9/14/04

## MI: LM402G

- 5 ms/div

- ~0.4pC/div
- (per 20μs)

- Large common-mode rejection from small choke
- Injection loss shows up cleanly

- BLM Upgrade -- J. Lewis

- 9/14/04

## MI: LM402G full cycle

- 25 ms/div

- ~0.2pC/div
- (per 20μs)

- Injection

- Extraction

- BLM Upgrade -- J. Lewis

- 9/14/04

## Worst Case Noise: LM322

- 1ms/div

- ~2pC/div
- (per 20μs)

- Raw

- 80 ft Choke

- Choke+25k

- BLM Upgrade -- J. Lewis

- 9/14/04

## Smoothing: LM522F

- 10 ms/div

- ~0.1pC/div
- (per 20μs)

- Raw

- Small Choke
- +25k

- Smoothed

- Smooth
- @1ms

- BLM Upgrade -- J. Lewis

- 9/14/04

## Tevatron: LMF0DT

- 5 ms/div

- ~2pC/div
- (per 20μs)

**Proton Injection Loss During Shot Setup 8/22/04**

- BLM Upgrade -- J. Lewis

- 9/14/04

## LMF12: Old and New

**1 ms/div**

**~0.2pC/div**
**(per 20μs)**

**Small Choke**

**Small Choke,**
**Smooth @ 100μs**

**LMF 12**
**0.025 R/s **
**per div**

**100 ms/div**

- BLM Upgrade -- J. Lewis

- 9/14/04

## Outstanding Issues

**Software, software, software**
**Need detailed specs for software for Tev, MI and Booster**
**Need front-end and applications programmers**
**MDAT**
**How are signals generated? **
**How do we get them?**
**Timing**
**Where do we get primary clock (AA marker)**

- BLM Upgrade -- J. Lewis

- 9/14/04