# Presentation: 775597

## RUN-03 pp2pp Readiness

- Włodek Guryn

- Goals of the RUN-03:
- Measure AN in the 0.003 < *-t *< 0.02 (GeV/c)2
-     with 0.2% error;
- Improve nuclear slope B measurement  from current 10% error down to 3%;
- Measure **Tot** with 5-10% error, which requires luminosity measurement with 5% error.

## The Setup

- Improvements  of the to the last year’s setup:
- The setup is twice “bigger” than last year – it includes two Roman pot stations fully instrumented on each side, allowing measurement of  the angle and position of the scattered proton;
- New running conditions have been requested, implementation is in progress, to allow moving the pots down to 6mm from the beam, thus increasing the acceptance for the **A****N** measurement;
- New Si strip detectors, made by Hamamatsu, will be used – they have been delivered;
- New sequencers for Si readout are being tested at ITEP;
- New DAQ is under construction to improve data rate up to 400 Hz.

- Vacuum

- Bellows

- UHVChamber

**Roman Pot****Station 1**

**Roman Pot**
**Station 2**

- LearSlide

## Some Transport Issues

- Improvement: Measure angle and position at RP to solve for x0, y0 and scatt. angles

- Design transport: (x0, y0) are known, a11or a33 small  parallel to point focusing

**Actual transport is**** ****not known and is also coupled (x,y) because of the quad roll**

## Readiness

- Status:
- Si Detectors, pp2pp setup under control;
- Need formal approval from ASSC in CAD to take data with higher intensity and at closer distance. Implementation of safety measures is under way;
- Scheme for 5% error in luminosity measurement needs work and planning;
- Scheme for accurate tune measurement to reduce systematic error due to the transport uncertainty needs work and planning (CAD).
- No problem with tune setup since injection and ramp with * =10 m

## Event Rates 

- With 110 bunches at 10**11**/bunch, after scraping by factor of four the RUN-03 beam intensity would be 3x10**12**, compared to 5x1011 in RUN-02;
-  Roman pot operation at the distance down to 6-8mm from the beam;
- This would result in the first strip to be at ~ 8-10 mm

**Running at the above intensity, about 6 times last year’s, gives trigger rate 162 Hz at y****min**** = 15 mm, RUN-02 useful rate in the t-acceptance for spin was 9 Hz. **
**At y****min**** = 10 mm the above rate increases by 50%.**
**Use 80 Hz as conservative estimate, in case highest intensity is not achieved for y****min**** = 15 mm and 120 Hz for y****min**** = 10 mm**

## Running time

- Where  is the dilution factor, which depends on the acceptance in 
- FY-02 run, ymin= 15 mm  0.44
- FY-03 run, ymin= 10 mm  

- One data point with   AN = 0.002, P = 0.40 will require
- Ntot= 8.1 M events at ymin= 15 mm  2.0 days (14 hr/day)
- Ntot= 5.6 M events at ymin= 10 mm  1.0 days (14 hr/day)
- With the above statistics B/B < 3%
- We need roughly a TWO-DAY run this year.

## Summary

- No obvious show stoppers in preparation for the run;
- Tasks to watch, pp2pp:
- Si assembly and testing,
- new sequencer (ITEP),
- Trigger commissioning;
- Requirements for the run:
- High intensity,
- Good vertex, since transport depends on z,
- Accurate luminosity measurement,
- Will need short periods for commissioning, not a dedicated time.
**We can do physics with a short, two day run.**