RPC Temperature Studies

A. Cimmino

Temperature Studies

• 310 temperature sensors are collocated throughout the barrel.

• Temperatures are monitored by the RPC DCS system online

• Values are written in OMDS with a 0.3°C dead band (sensor resolution).

• Temperatures measured during Cruzet3 & 4 were analyzed and are here presented.

• The behavior of each single sensor has been studied.

Average Temperature for 3 Wheels during Cruzet3

Wheel0 appears to be the hottest one at all times

In 6 days the average temperature of the wheels increases of ~ 1 -1.5°C as you may see from the next slide62 sensors/Wheel

Temperature Distribution for 3 Wheels at the beginning and end of

Cruzet3

Black = 07/07/2008 2pmRed = 13/07/2008 2pm

While the average temperature is below the critical value (23°C) our concern are due to these tails

Average Temperature Plot and Distribution for Reference sensors during Cruzet3

Compatible with a horizontal line

Possible heating sources• RPC FEB LVs• DT FEB & MiniCrate LVs• ECAL Cables(???)

What happens if RPC LVs are turned off?

LVs OFF from 09/07/2008 7pm

Slopes measured in

°C/day

(8.5 ± 1.1) * 10-2

(11.5 ± 1.3) * 10-2

(9.0 ± 1.2) * 10-2

(9.9 ± 1.3) * 10-2

(9.3 ± 1.1) * 10-2

~1°C every 10 days of increase

DT minicrates ON

What happens if DT LVs are off?

Data from Cruzet4DT LV off the entire period on Sectors 6 & 7 Wheel-2RPC FEBs ON

DTemp with DT OFF & RPC ON

°C

Temperature increase distribution after 5 days with DT LVs OFF

W-2 Sector 4 RB1in & RB1out

Temperature with DT&RPC ON

DT ON – Cruzet4

Weekend = RPC ON & DT OFF

~ 2.5 °C of increase during Cruzet 4 week

---------

~1.5°C of increase in the

first day

Temperature of water during Cruzet 4

°C

Sensor stopped reading ~2.5 hours

Cooling Schema

Flow-limiters 1.5 liter/minute

1.5 x 50/2 = 37 l/min/wheel

1.5 x 50/2 = 37 l/min/wheel

Cooling

• Cooling water is shared by 2 adjacent sector

• Sectors are twined as shown in the tables

IN OUT

12 11

10 9

8 7

6 5

4 3

2 1

IN OUT

12 1

2 3

4 5

6 7

8 9

10 11

Wheels +1,0,-1,-2 Wheel +2

IN

OUTRB4

RB4RB3

RB2

RB1 RB1

RB2

RB3

DTemp between RB4 and RB1in

Even Sectors

Odd Sectors

Temperature Distribution by Stations

RB1in

RB1out

RB2

RB3

RB4

Temperatures refer to the 11/07/2008 2pmTemperatures refer to the 11/07/2008 2pm