# Presentation: 402135

## Triggering MICE:Very Preliminary Thoughts

- Steve Kahn
- Brookhaven National Lab

- Trigger MICE

- Oct 25, 2002 S. Kahn

## What Should the Triggering Do?

- We should like to trigger on a *good muon track.*
- We do not want to waste time writing out TPG or SciFi hits if the track is not a good muon candidate.
- Is this true?  Is there time to write out everything to a buffer and not worry about triggering at all?
- For data rate considerations alone we could take everything.
- We also don’t necessarily want to trigger if the beam conditions are bad for some reason
- Beam is mis-steered on a particular beam cycle.
- We may want to trigger an a particular part of the phase space.
- This may or may not be possible.

- Trigger MICE

- Oct 25, 2002 S. Kahn

## Data Rates

| Detector | Data Rate |
| --- | --- |
| TPG | 10 Mb/s |
| SciFi | 40 Mb/s |
| TOF | 0.5 Mb/s |

*From E. Radicioni’s Transparency*

- This data rates are not excessive

- Trigger MICE

- Oct 25, 2002 S. Kahn

## Why Trigger?

- We could trigger to reduce the background.
- TOF 1 and 2 can verify a muon.  This signal can be used to trigger a tight time gate for other detectors.
- In this case detectors would only be sensitive to background Xrays during the minimum gated time.
- This will be the triggering scheme that will be pursued.

- Trigger MICE

- Oct 25, 2002 S. Kahn

##  measurement precision can be as good as out/ in ) = 10-3

**T.O.F. III**
**Precise timing**

**Electron ID**
**Eliminate muons that decay  **

**Tracking devices: **
**He filled TPC-GEM (similar to TSLA R&D)**
**or sci-fi**
**Measurement of momentum angles and position**

**T.O.F. I & II**
**Pion /muon ID**
**precise timing**

** ****10% cooling of 200 MeV muons requires ~ 20 MV of RF**
_** **__**single particle measurements**_** =>**
** ****measurement precision can be as good as ********out****/******** in ****) = 10****-3**

**201 MHz RF**** ****cavities**

**Liquid H2 absorbers**
**or LiH ?**

**SC Solenoids;**
**Spectrometer, focus pair, compensation coil**

**LOI submitted to PSI and RAL. **
**The two labs agreed to collaborate and RAL encourages submission of proposal. 2002: prepare proposal.**** **

- Trigger MICE

- Oct 25, 2002 S. Kahn

## Triggering Using TOF System

- The figure shows the time difference between  and  with specified momentum to traverse 10 m.
- The TOF time resolution is expected to be better than 200 ps.  This is adequate to distinguish  from .
- Good Muon can be defined as a coincidence.
**TOF1 * TOF2 **with proper time delay

- Trigger MICE

- Oct 25, 2002 S. Kahn

## Data Taking Scenario

- RF Duty Cycle: 10-3  1 ms in each second

- 150 s rise time required for turn on of RF.

- 1 Hz:

- 

- RF off *flat top*

- 2 Hz :

- The choice of 1Hz or 2 Hz depends on how large the buffers are or what electronics are used.

*From V. Palladino*

- For background studies

- Trigger MICE

- Oct 25, 2002 S. Kahn

## Data Taking Scenario (cont.)

- ISIS Bunch Structure

- In 850 s there are 2600 bunches

- Assuming ~1 /bunch in TOF 1

-  0.25 /bunch in TOF 2 (geometric factor)

-  0.04 /bunch in phase w/RF (factor 1/6)

- 2600 bunches gives 100 /sec

- For 1% errors we need 105 muons

- Typical run would be 1000 sec.

- Trigger MICE

- Oct 25, 2002 S. Kahn

## RFcooling

- RFcooling

- Start of RF

- 350-850 s

- RFISIS

- 100 ns

- 230 ns

-  Bunch train

- Typical 

- TOF1

- TOF sets a starting trigger signal with a resolution of ~100 ps

- SciFi

- The SciFi is gated for 20 ns against TOF start trigger

- 20 ns

- TPG

- 500 ns

- 1024 boxes

- 500 s total

- TPG triggered off *start of RF*

- From V. Palladino

- Čdown, Ecal

- stops

- Trigger MICE

- Oct 25, 2002 S. Kahn

## Specific Detector Comments

- SciFi Detector.
- The minimum required active time is 20 ns.
- This 20 ns gate can be triggered by the TOF.
- This will specify where in the 100 ns bucket the  is.
- The SciFi need not be active during the whole RF cycle, which will reduce the background from Xrays.
- TPG Detector.
- The TPG would trigger off the *start of RF* signal.
- It would stay active for 500 s.
- The TPG is less sensitive to background.
- The Č and E-cal are reasonably fast and could be triggered in a manner similar to the SciFi.
- The Č is fast enough for a 10 ns gate.(?)

- Trigger MICE

- Oct 25, 2002 S. Kahn

## Trigger

- TOF I

- TOF II

- TOF III

- TPG or
- Fiber Tracker

- TOF I

- TOF II

- TOF III

- FTrac I

- FTrac II

- FTrac III

- FTrac IV

- TDC

- DISC

- RF gate

- Modified D0 fiber DAQ

- TDC

- TDC

- TDC

- Gate Gen.

*From K. Lee*

- Trigger MICE

- Oct 25, 2002 S. Kahn